PIC16F870/871 28/40-Pin, 8-Bit CMOS FLASH Microcontrollers * PIC16F870 * PIC16F871 Microcontroller Core Features: * High performance RISC CPU * Only 35 single word instructions to learn * All single cycle instructions except for program branches which are two-cycle * Operating speed: DC - 20 MHz clock input DC - 200 ns instruction cycle * 2K x 14 words of FLASH Program Memory 128 x 8 bytes of Data Memory (RAM) 64 x 8 bytes of EEPROM Data Memory * Pinout compatible to the PIC16CXXX 28 and 40-pin devices * Interrupt capability (up to 11 sources) * Eight level deep hardware stack * Direct, Indirect and Relative Addressing modes * Power-on Reset (POR) * Power-up Timer (PWRT) and Oscillator Start-up Timer (OST) * Watchdog Timer (WDT) with its own on-chip RC oscillator for reliable operation * Programmable code protection * Power saving SLEEP mode * Selectable oscillator options * Low power, high speed CMOS FLASH/EEPROM technology * Fully static design * In-Circuit Serial Programming(ICSP)via two pins * Single 5V In-Circuit Serial Programming capability * In-Circuit Debugging via two pins * Processor read/write access to program memory * Wide operating voltage range: 2.0V to 5.5V * High Sink/Source Current: 25 mA * Commercial and Industrial temperature ranges * Low power consumption: - < 1.6 mA typical @ 5V, 4 MHz - 20 A typical @ 3V, 32 kHz - < 1 A typical standby current 2000-2013 Microchip Technology Inc. Pin Diagram PDIP MCLR/VPP/THV RA0/AN0 RA1/AN1 RA2/AN2/VREFRA3/AN3/VREF+ RA4/T0CKI RA5/AN4 RE0/RD/AN5 RE1/WR/AN6 RE2/CS/AN7 VDD VSS OSC1/CLKI OSC2/CLKO RC0/T1OSO/T1CKI RC1/T1OSI RC2/CCP1 RC3 RD0/PSP0 RD1/PSP1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 PIC16F871 Devices Included in this Data Sheet: 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 RB7/PGD RB6/PGC RB5 RB4 RB3/PGM RB2 RB1 RB0/INT VDD VSS RD7/PSP7 RD6/PSP6 RD5/PSP5 RD4/PSP4 RC7/RX/DT RC6/TX/CK RC5 RC4 RD3/PSP3 RD2/PSP2 Peripheral Features: * Timer0: 8-bit timer/counter with 8-bit prescaler * Timer1: 16-bit timer/counter with prescaler, can be incremented during SLEEP via external crystal/clock * Timer2: 8-bit timer/counter with 8-bit period register, prescaler and postscaler * One Capture, Compare, PWM module - Capture is 16-bit, max. resolution is 12.5 ns - Compare is 16-bit, max. resolution is 200 ns - PWM max. resolution is 10-bit * 10-bit multi-channel Analog-to-Digital converter * Universal Synchronous Asynchronous Receiver Transmitter (USART/SCI) with 9-bit address detection * Parallel Slave Port (PSP) 8-bits wide, with external RD, WR and CS controls (40/44-pin only) * Brown-out detection circuitry for Brown-out Reset (BOR) DS30569C-page 1 PIC16F870/871 Pin Diagrams 28 27 26 25 24 23 22 21 20 19 18 17 16 15 RB7/PGD RB6/PGC RB5 RB4 RB3/PGM RB2 RB1 RB0/INT VDD VSS RC7/RX/DT RC6/TX/CK RC5 RC4 6 5 4 3 2 1 44 43 42 41 40 PLCC RA3/AN3/VREF+ RA2/AN2/VREFRA1/AN1 RA0/AN0 MCLR/VPP/THV NC RB7/PGD RB6/PGC RB5 RB4 NC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 MCLR/VPP/THV RA0/AN0 RA1/AN1 RA2/AN2/VREFRA3/AN3/VREF+ RA4/T0CKI RA5/AN4 VSS OSC1/CLKI OSC2/CLKO RC0/T1OSO/T1CKI RC1/T1OSI RC2/CCP1 RC3 PIC16F870 DIP, SOIC, SSOP 18 19 20 21 22 23 24 25 26 27 282 PIC16F871 39 38 37 36 35 34 33 32 31 30 9 RB3/PGM RB2 RB1 RB0/INT VDD VSS RD7/PSP7 RD6/PSP6 RD5/PSP5 RD4/PSP4 RC7/RX/DT 44 43 42 41 40 39 38 37 36 35 34 TQFP 7 8 9 10 11 12 13 14 15 16 17 RC1/T1OSI RC2/CCP1 RC3 RD0/PSP0 RD1/PSP1 RD2/PSP2 RD3/PSP3 RC4 RC5 RC6/TX/CK NC RC6/TX/CK RC5 RC4 RD3/PSP3 RD2/PSP2 RD1/PSP1 RD0/PSP0 RC3 RC2/CCP1 RC1/T1OSI NC RA4/T0CKI RA5/AN4 RE0/RD/AN5 RE1/WR/AN6 RE2/CS/AN7 VDD VSS OSC1/CLKI OSC2/CLKO RC0/T1OSO/T1CK1 NC PIC16F871 33 32 31 30 29 28 27 26 25 24 23 12 13 14 15 16 17 18 19 20 21 22 1 2 3 4 5 6 7 8 9 10 11 NC RC0/T1OSO/T1CKI OSC2/CLKO OSC1/CLKI VSS VDD RE2/CS/AN7 RE1/WR/AN6 RE0/RD/AN5 RA5/AN4 RA4/T0CKI NC NC RB4 RB5 RB6/PGC RB7/PGD MCLR/VPP/THV RA0/AN0 RA1/AN1 RA2/AN2/VREFRA3/AN3/VREF+ RC7/RX/DT RD4/PSP4 RD5/PSP5 RD6/PSP6 RD7/PSP7 VSS VDD RB0/INT RB1 RB2 RB3/PGM DS30569C-page 2 2000-2013 Microchip Technology Inc. PIC16F870/871 Key Features PICmicroTM Mid-Range MCU Family Reference Manual (DS33023) PIC16F870 PIC16F871 Operating Frequency DC - 20 MHz DC - 20 MHz RESETS (and Delays) POR, BOR (PWRT, OST) POR, BOR (PWRT, OST) FLASH Program Memory (14-bit words) 2K 2K Data Memory (bytes) 128 128 EEPROM Data Memory 64 64 Interrupts 10 11 I/O Ports Ports A,B,C Ports A,B,C,D,E 3 3 Timers Capture/Compare/PWM modules Serial Communications Parallel Communications 10-bit Analog-to-Digital Module Instruction Set 2000-2013 Microchip Technology Inc. 1 1 USART USART -- PSP 5 input channels 8 input channels 35 Instructions 35 Instructions DS30569C-page 3 PIC16F870/871 Table of Contents 1.0 Device Overview .......................................................................................................................................................................... 5 2.0 Memory Organization ................................................................................................................................................................. 11 3.0 Data EEPROM and Flash Program Memory.............................................................................................................................. 27 4.0 I/O Ports ..................................................................................................................................................................................... 33 5.0 Timer0 Module ........................................................................................................................................................................... 45 6.0 Timer1 Module ........................................................................................................................................................................... 49 7.0 Timer2 Module ........................................................................................................................................................................... 53 8.0 Capture/Compare/PWM Modules .............................................................................................................................................. 55 9.0 Addressable Universal Synchronous Asynchronous Receiver Transmitter (USART)................................................................ 61 10.0 Analog-to-Digital (A/D) Converter Module .................................................................................................................................. 79 11.0 Special Features of the CPU ...................................................................................................................................................... 87 12.0 Instruction Set Summary .......................................................................................................................................................... 103 13.0 Development Support............................................................................................................................................................... 111 14.0 Electrical Characteristics .......................................................................................................................................................... 117 15.0 DC and AC Characteristics Graphs and Tables ....................................................................................................................... 137 16.0 Packaging Information.............................................................................................................................................................. 149 Appendix A: Revision History............................................................................................................................................................. 157 Appendix B: Device Differences......................................................................................................................................................... 157 Appendix C: Conversion Considerations ........................................................................................................................................... 158 Appendix D: Migration from Mid-Range to Enhanced Devices .......................................................................................................... 158 Appendix E: Migration from High-End to Enhanced Devices............................................................................................................. 159 Index .................................................................................................................................................................................................. 161 On-Line Support................................................................................................................................................................................. 167 Systems Information and Upgrade Hot Line ...................................................................................................................................... 167 Reader Response .............................................................................................................................................................................. 168 PIC16F870/871 Product Identification System .................................................................................................................................. 169 TO OUR VALUED CUSTOMERS It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and enhanced as new volumes and updates are introduced. If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via E-mail at docerrors@mail.microchip.com or fax the Reader Response Form in the back of this data sheet to (480) 792-4150. We welcome your feedback. Most Current Data Sheet To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at: http://www.microchip.com You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page. The last character of the literature number is the version number, (e.g., DS30000A is version A of document DS30000). Errata An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the revision of silicon and revision of document to which it applies. To determine if an errata sheet exists for a particular device, please check with one of the following: * Microchip's Worldwide Web site; http://www.microchip.com * Your local Microchip sales office (see last page) * The Microchip Corporate Literature Center; U.S. FAX: (480) 792-7277 When contacting a sales office or the literature center, please specify which device, revision of silicon and data sheet (include literature number) you are using. Customer Notification System Register on our web site at www.microchip.com/cn to receive the most current information on all of our products. DS30569C-page 4 2000-2013 Microchip Technology Inc. PIC16F870/871 1.0 DEVICE OVERVIEW There are two devices (PIC16F870 and PIC16F871) covered by this data sheet. The PIC16F870 device comes in a 28-pin package and the PIC16F871 device comes in a 40-pin package. The 28-pin device does not have a Parallel Slave Port implemented. This document contains device specific information. Additional information may be found in the PICmicroTM Mid-Range MCU Family Reference Manual (DS33023), which may be obtained from your local Microchip Sales Representative or downloaded from the Microchip web site. The Reference Manual should be considered a complementary document to this data sheet, and is highly recommended reading for a better understanding of the device architecture and operation of the peripheral modules. FIGURE 1-1: The following two figures are device block diagrams sorted by pin number: 28-pin for Figure 1-1 and 40-pin for Figure 1-2. The 28-pin and 40-pin pinouts are listed in Table 1-1 and Table 1-2, respectively. PIC16F870 BLOCK DIAGRAM Device Program FLASH Data Memory Data EEPROM PIC16F870 2K 128 Bytes 64 Bytes 13 FLASH Program Memory 14 PORTA RA0/AN0 RA1/AN1 RA2/AN2/VREFRA3/AN3/VREF+ RA4/T0CKI RA5/AN4 RAM File Registers 8 Level Stack (13-bit) Program Bus 8 Data Bus Program Counter RAM Addr (1) PORTB 9 Addr MUX Instruction reg Direct Addr 7 8 Indirect Addr FSR reg STATUS reg 8 3 Power-up Timer Instruction Decode & Control Timing Generation OSC1/CLKI OSC2/CLKO Oscillator Start-up Timer Power-on Reset Watchdog Timer Brown-out Reset In-Circuit Debugger MUX ALU PORTC RB0/INT RB1 RB2 RB3/PGM RB4 RB5 RB6/PGC RB7/PGD RC0/T1OSO/T1CKI RC1/T1OSI RC2/CCP1 RC3 RC4 RC5 RC6/TX/CK RC7/RX/DT 8 W reg Low-Voltage Programming MCLR Timer0 Timer1 Data EEPROM CCP1 Note 1: VDD, VSS Timer2 10-bit A/D USART Higher order bits are from the STATUS register. 2000-2013 Microchip Technology Inc. DS30569C-page 5 PIC16F870/871 FIGURE 1-2: PIC16F871 BLOCK DIAGRAM Device Program FLASH Data Memory Data EEPROM PIC16F871 2K 128 Bytes 64 Bytes 13 Program Memory 14 PORTA RA0/AN0 RA1/AN1 RA2/AN2/VREFRA3/AN3/VREF+ RA4/T0CKI RA5/AN4 RAM File Registers 8 Level Stack (13-bit) Program Bus 8 Data Bus Program Counter FLASH RAM Addr (1) PORTB 9 Addr MUX Instruction reg Direct Addr 7 8 Indirect Addr FSR reg STATUS reg 8 3 Power-up Timer Instruction Decode & Control Timing Generation OSC1/CLKI OSC2/CLKO Oscillator Start-up Timer Power-on Reset PORTC RC0/T1OSO/T1CKI RC1/T1OSI RC2/CCP1 RC3 RC4 RC5 RC6/TX/CK RC7/RX/DT MUX ALU 8 Watchdog Timer Brown-out Reset RB0/INT RB1 RB2 RB3/PGM RB4 RB5 RB6/PGC RB7/PGD PORTD W reg RD7/PSP7:RD0/PSP0 In-Circuit Debugger Low-Voltage Programming PORTE RE0/RD/AN5 RE1/WR/AN6 MCLR Timer0 Timer1 Data EEPROM CCP1 Note 1: VDD, VSS Timer2 Parallel Slave Port RE2/CS/AN7 10-bit A/D USART Higher order bits are from the STATUS register. DS30569C-page 6 2000-2013 Microchip Technology Inc. PIC16F870/871 TABLE 1-1: PIC16F870 PINOUT DESCRIPTION DIP Pin# SOIC Pin# I/O/P Type OSC1/CLKI 9 9 I OSC2/CLKO 10 10 O -- Oscillator crystal output. Connects to crystal or resonator in Crystal Oscillator mode. In RC mode, the OSC2 pin outputs CLKO, which has 1/4 the frequency of OSC1, and denotes the instruction cycle rate. MCLR/VPP/THV 1 1 I/P ST Master Clear (Reset) input or programming voltage input or High Voltage Test mode control. This pin is an active low RESET to the device. Pin Name Buffer Type Description ST/CMOS(3) Oscillator crystal input/external clock source input. PORTA is a bi-directional I/O port. RA0/AN0 2 2 I/O TTL RA0 can also be analog input 0. RA1/AN1 3 3 I/O TTL RA1 can also be analog input 1. RA2/AN2/VREF- 4 4 I/O TTL RA2 can also be analog input 2 or negative analog reference voltage. RA3/AN3/VREF+ 5 5 I/O TTL RA3 can also be analog input 3 or positive analog reference voltage. RA4/T0CKI 6 6 I/O ST/OD RA4 can also be the clock input to the Timer0 module. Output is open drain type. RA5/AN4 7 7 I/O TTL RA5 can also be analog input 4. PORTB is a bi-directional I/O port. PORTB can be software programmed for internal weak pull-up on all inputs. RB0/INT 21 21 I/O TTL/ST(1) RB1 22 22 I/O TTL RB2 23 23 I/O TTL RB3/PGM 24 24 I/O TTL/ST(1) RB4 25 25 I/O TTL RB5 26 26 I/O TTL RB6/PGC 27 27 I/O TTL/ST(2) Interrupt-on-change pin or In-Circuit Debugger pin. Serial programming clock. RB7/PGD 28 28 I/O TTL/ST(2) Interrupt-on-change pin or In-Circuit Debugger pin. Serial programming data. RC0/T1OSO/T1CKI 11 11 I/O ST RC0 can also be the Timer1 oscillator output or Timer1 clock input. RC1/T1OSI 12 12 I/O ST RC1 can also be the Timer1 oscillator input. RC2/CCP1 13 13 I/O ST RC2 can also be the Capture1 input/Compare1 output/ PWM1 output. RC3 14 14 I/O ST RC4 15 15 I/O ST RC5 16 16 I/O ST RC6/TX/CK 17 17 I/O ST RC6 can also be the USART Asynchronous Transmit or Synchronous Clock. RC7/RX/DT 18 18 I/O ST RC7 can also be the USART Asynchronous Receive or Synchronous Data. VSS 8, 19 8, 19 P -- Ground reference for logic and I/O pins. VDD 20 20 P -- Positive supply for logic and I/O pins. RB0 can also be the external interrupt pin. RB3 can also be the low voltage programming input. Interrupt-on-change pin. Interrupt-on-change pin. PORTC is a bi-directional I/O port. Legend: Note 1: 2: 3: I = input O = output I/O = input/output P = power OD = Open Drain -- = Not used TTL = TTL input ST = Schmitt Trigger input This buffer is a Schmitt Trigger input when configured as the external interrupt or LVP mode. This buffer is a Schmitt Trigger input when used in Serial Programming mode. This buffer is a Schmitt Trigger input when configured in RC Oscillator mode and a CMOS input otherwise. 2000-2013 Microchip Technology Inc. DS30569C-page 7 PIC16F870/871 TABLE 1-2: PIC16F871 PINOUT DESCRIPTION DIP Pin# PLCC Pin# QFP Pin# I/O/P Type Buffer Type OSC1/CLKI 13 14 30 I ST/CMOS(4) OSC2/CLKO 14 15 31 O -- Oscillator crystal output. Connects to crystal or resonator in Crystal Oscillator mode. In RC mode, OSC2 pin outputs CLKO, which has 1/4 the frequency of OSC1, and denotes the instruction cycle rate. MCLR/VPP/THV 1 2 18 I/P ST Master Clear (Reset) input or programming voltage input or High Voltage Test mode control. This pin is an active low RESET to the device. RA0/AN0 2 3 19 I/O TTL RA0 can also be analog input 0. RA1/AN1 3 4 20 I/O TTL RA1 can also be analog input 1. RA2/AN2/VREF- 4 5 21 I/O TTL RA2 can also be analog input 2 or negative analog reference voltage. RA3/AN3/VREF+ 5 6 22 I/O TTL RA3 can also be analog input 3 or positive analog reference voltage. RA4/T0CKI 6 7 23 I/O ST RA4 can also be the clock input to the Timer0 timer/counter. Output is open drain type. RA5/AN4 7 8 24 I/O TTL Pin Name Description Oscillator crystal input/external clock source input. PORTA is a bi-directional I/O port. RA5 can also be analog input 4. PORTB is a bi-directional I/O port. PORTB can be software programmed for internal weak pull-up on all inputs. RB0/INT 33 36 8 I/O TTL/ST(1) RB1 34 37 9 I/O TTL RB2 35 38 10 I/O TTL RB3/PGM 36 39 11 I/O TTL/ST(1) RB4 37 41 14 I/O TTL RB5 38 42 15 I/O TTL RB6/PGC 39 43 16 I/O TTL/ST (2) Interrupt-on-change pin or In-Circuit Debugger pin. Serial programming clock. RB7/PGD 40 44 17 I/O TTL/ST(2) Interrupt-on-change pin or In-Circuit Debugger pin. Serial programming data. RB0 can also be the external interrupt pin. RB3 can also be the low voltage programming input. Interrupt-on-change pin. Interrupt-on-change pin. PORTC is a bi-directional I/O port. RC0/T1OSO/T1CKI 15 16 32 I/O ST RC0 can also be the Timer1 oscillator output or a Timer1 clock input. RC1/T1OSI 16 18 35 I/O ST RC1 can also be the Timer1 oscillator input. RC2/CCP1 17 19 36 I/O ST RC2 can also be the Capture1 input/Compare1 output/ PWM1 output. RC3 18 20 37 I/O ST RC4 23 25 42 I/O ST RC5 24 26 43 I/O ST RC6/TX/CK 25 27 44 I/O ST RC6 can also be the USART Asynchronous Transmit or Synchronous Clock. RC7/RX/DT 26 29 1 I/O ST RC7 can also be the USART Asynchronous Receive or Synchronous Data. Legend: Note 1: 2: 3: 4: I = input O = output I/O = input/output P = power -- = Not used TTL = TTL input ST = Schmitt Trigger input This buffer is a Schmitt Trigger input when configured as an external interrupt or LVP mode. This buffer is a Schmitt Trigger input when used in Serial Programming mode. This buffer is a Schmitt Trigger input when configured as general purpose I/O and a TTL input when used in the Parallel Slave Port mode (for interfacing to a microprocessor bus). This buffer is a Schmitt Trigger input when configured in RC Oscillator mode and a CMOS input otherwise. DS30569C-page 8 2000-2013 Microchip Technology Inc. PIC16F870/871 TABLE 1-2: Pin Name PIC16F871 PINOUT DESCRIPTION (CONTINUED) DIP Pin# PLCC Pin# QFP Pin# I/O/P Type Buffer Type Description PORTD is a bi-directional I/O port or parallel slave port when interfacing to a microprocessor bus. RD0/PSP0 19 21 38 I/O ST/TTL(3) RD1/PSP1 20 22 39 I/O ST/TTL(3) RD2/PSP2 21 23 40 I/O ST/TTL(3) RD3/PSP3 22 24 41 I/O ST/TTL(3) RD4/PSP4 27 30 2 I/O ST/TTL(3) RD5/PSP5 28 31 3 I/O ST/TTL(3) RD6/PSP6 29 32 4 I/O ST/TTL(3) RD7/PSP7 30 33 5 I/O ST/TTL(3) RE0/RD/AN5 8 9 25 I/O ST/TTL (3) RE0 can also be read control for the parallel slave port, or analog input 5. RE1/WR/AN6 9 10 26 I/O ST/TTL(3) RE1 can also be write control for the parallel slave port, or analog input 6. RE2/CS/AN7 10 11 27 I/O ST/TTL(3) RE2 can also be select control for the parallel slave port, or analog input 7. PORTE is a bi-directional I/O port. VSS 12,31 13,34 6,29 P -- Ground reference for logic and I/O pins. VDD 11,32 12,35 7,28 P -- Positive supply for logic and I/O pins. NC -- 1,17,28, 40 12,13, 33,34 -- These pins are not internally connected. These pins should be left unconnected. Legend: Note 1: 2: 3: 4: I = input O = output I/O = input/output P = power -- = Not used TTL = TTL input ST = Schmitt Trigger input This buffer is a Schmitt Trigger input when configured as an external interrupt or LVP mode. This buffer is a Schmitt Trigger input when used in Serial Programming mode. This buffer is a Schmitt Trigger input when configured as general purpose I/O and a TTL input when used in the Parallel Slave Port mode (for interfacing to a microprocessor bus). This buffer is a Schmitt Trigger input when configured in RC Oscillator mode and a CMOS input otherwise. 2000-2013 Microchip Technology Inc. DS30569C-page 9 PIC16F870/871 NOTES: DS30569C-page 10 2000-2013 Microchip Technology Inc. PIC16F870/871 2.0 MEMORY ORGANIZATION The PIC16F870/871 devices have three memory blocks. The Program Memory and Data Memory have separate buses, so that concurrent access can occur, and is detailed in this section. The EEPROM data memory block is detailed in Section 3.0. 2.2 The data memory is partitioned into multiple banks which contain the General Purpose Registers and the Special Function Registers. Bits RP1 (STATUS<6>) and RP0 (STATUS<5>) are the bank select bits. Additional information on device memory may be found in the PICmicroTM Mid-Range MCU Family Reference Manual (DS33023). 2.1 Program Memory Organization The PIC16F870/871 devices have a 13-bit program counter capable of addressing an 8K x 14 program memory space. The PIC16F870/871 devices have 2K x 14 words of FLASH program memory. Accessing a location above the physically implemented address will cause a wraparound. The RESET vector is at 0000h and the interrupt vector is at 0004h. FIGURE 2-1: PIC16F870/871 PROGRAM MEMORY MAP AND STACK Bank 00 0 01 1 10 2 11 3 Note: EEPROM Data Memory description can be found in Section 3.0 of this Data Sheet. GENERAL PURPOSE REGISTER FILE The register file can be accessed either directly, or indirectly through the File Select Register FSR. 13 CALL, RETURN RETFIE, RETLW RP<1:0> Each bank extends up to 7Fh (128 bytes). The lower locations of each bank are reserved for the Special Function Registers. Above the Special Function Registers are General Purpose Registers, implemented as static RAM. All implemented banks contain Special Function Registers. Some "high use" Special Function Registers from one bank may be mirrored in another bank for code reduction and quicker access. 2.2.1 PC<12:0> Data Memory Organization Stack Level 1 Stack Level 2 Stack Level 8 On-Chip Program Memory RESET Vector 0000h Interrupt Vector 0004h 0005h Page 0 07FFh 0800h 1FFFh 2000-2013 Microchip Technology Inc. DS30569C-page 11 PIC16F870/871 FIGURE 2-2: PIC16F870/871 REGISTER FILE MAP File Address Indirect addr.(*) TMR0 PCL STATUS FSR PORTA PORTB PORTC PORTD(2) PORTE(2) PCLATH INTCON PIR1 PIR2 TMR1L TMR1H T1CON TMR2 T2CON CCPR1L CCPR1H CCP1CON RCSTA TXREG RCREG ADRESH ADCON0 00h 01h 02h 03h 04h 05h 06h 07h 08h 09h 0Ah 0Bh 0Ch 0Dh 0Eh 0Fh 10h 11h 12h 13h 14h 15h 16h 17h 18h 19h 1Ah 1Bh 1Ch 1Dh 1Eh 1Fh 20h General Purpose Register File Address Indirect addr.(*) 80h OPTION_REG 81h PCL 82h STATUS 83h FSR 84h TRISA 85h TRISB 86h TRISC 87h 88h TRISD(2) (2) TRISE 89h PCLATH 8Ah INTCON 8Bh PIE1 8Ch PIE2 8Dh PCON 8Eh 8Fh 90h 91h PR2 92h 93h 94h 95h 96h 97h TXSTA 98h SPBRG 99h 9Ah 9Bh 9Ch 9Dh ADRESL 9Eh 9Fh ADCON1 General Purpose Register A0h 32 Bytes BFh C0h 96 Bytes 7Fh Bank 0 accesses 70h-7Fh Bank 1 Indirect addr.(*) 100h 101h TMR0 102h PCL 103h STATUS 104h FSR 105h 106h PORTB 107h 108h 109h 10Ah PCLATH 10Bh INTCON 10Ch EEDATA EEADR 10Dh 10Eh EEDATH 10Fh EEADRH 110h Indirect addr.(*) OPTION_REG PCL STATUS FSR TRISB PCLATH INTCON EECON1 EECON2 Reserved(1) Reserved(1) 180h 181h 182h 183h 184h 185h 186h 187h 188h 189h 18Ah 18Bh 18Ch 18Dh 18Eh 18Fh 190h 1A0h 120h accesses A0h - BFh accesses 20h-7Fh EFh F0h File Address File Address 1BFh 1C0h accesses 70h-7Fh FFh Bank 2 16Fh 170h 17Fh accesses 70h-7Fh 1EFh 1F0h 1FFh Bank 3 Unimplemented data memory locations, read as '0'. * Not a physical register. Note 1: These registers are reserved; maintain these registers clear. 2: These registers are not implemented on the PIC16F870. DS30569C-page 12 2000-2013 Microchip Technology Inc. PIC16F870/871 2.2.2 SPECIAL FUNCTION REGISTERS The Special Function Registers are registers used by the CPU and peripheral modules for controlling the desired operation of the device. These registers are implemented as static RAM. A list of these registers is given in Table 2-1. TABLE 2-1: Address The Special Function Registers can be classified into two sets: core (CPU) and peripheral. Those registers associated with the core functions are described in detail in this section. Those related to the operation of the peripheral features are described in detail in the peripheral feature section. SPECIAL FUNCTION REGISTER SUMMARY Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other RESETS(2) Bank 0 00h(4) INDF Addressing this location uses contents of FSR to address data memory (not a physical register) 0000 0000 0000 0000 01h TMR0 Timer0 Module's Register xxxx xxxx uuuu uuuu 02h(4) PCL Program Counter's (PC) Least Significant Byte 03h(4) STATUS IRP RP1 RP0 TO 0000 0000 0000 0000 PD Z DC C 0001 1xxx 000q quuu 04h(4) FSR 05h PORTA 06h PORTB PORTB Data Latch when written: PORTB pins when read 07h PORTC PORTC Data Latch when written: PORTC pins when read xxxx xxxx uuuu uuuu 08h(5) PORTD PORTD Data Latch when written: PORTD pins when read xxxx xxxx uuuu uuuu 09h(5) PORTE -- -- -- 0Ah(1,4) PCLATH -- -- -- Indirect Data Memory Address Pointer -- -- xxxx xxxx uuuu uuuu PORTA Data Latch when written: PORTA pins when read -- -- --0x 0000 --0u 0000 xxxx xxxx uuuu uuuu RE2 RE1 RE0 Write Buffer for the upper 5 bits of the Program Counter ---- -xxx ---- -uuu ---0 0000 ---0 0000 0Bh(4) INTCON GIE PEIE T0IE INTE RBIE T0IF INTF RBIF 0Ch PIR1 PSPIF(3) ADIF RCIF TXIF -- CCP1IF TMR2IF TMR1IF 0000 -000 0000 -000 0Dh PIR2 -- -- -- EEIF -- -- -- -- ---0 ---- ---0 ---- 0Eh TMR1L Holding Register for the Least Significant Byte of the 16-bit TMR1 Register 0Fh TMR1H Holding Register for the Most Significant Byte of the 16-bit TMR1 Register 10h T1CON 11h TMR2 12h T2CON -- -- T1CKPS1 xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON --00 0000 --uu uuuu TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000 Timer2 Module's Register -- 0000 000x 0000 000u 0000 0000 0000 0000 13h -- Unimplemented -- -- 14h -- Unimplemented -- -- 15h CCPR1L Capture/Compare/PWM Register1 (LSB) 16h CCPR1H Capture/Compare/PWM Register1 (MSB) 17h CCP1CON xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu -- -- CCP1X CCP1Y CCP1M3 CCP1M2 CCP1M1 SPEN RX9 SREN CREN ADDEN FERR OERR CCP1M0 --00 0000 --00 0000 18h RCSTA 19h TXREG USART Transmit Data Register 0000 0000 0000 0000 1Ah RCREG USART Receive Data Register 0000 0000 0000 0000 1Bh -- Unimplemented -- -- 1Ch -- Unimplemented -- -- 1Dh -- Unimplemented -- -- 1Eh ADRESH 1Fh ADCON0 Legend: Note 1: 2: 3: 4: 5: RX9D A/D Result Register High Byte ADCS1 ADCS0 CHS2 0000 000x 0000 000x xxxx xxxx uuuu uuuu CHS1 CHS0 GO/DONE -- ADON 0000 00-0 0000 00-0 x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as '0', r = reserved. Shaded locations are unimplemented, read as `0'. The upper byte of the program counter is not directly accessible. PCLATH is a holding register for the PC<12:8> whose contents are transferred to the upper byte of the program counter. Other (non Power-up) Resets include external RESET through MCLR and Watchdog Timer Reset. Bits PSPIE and PSPIF are reserved on the 28-pin devices; always maintain these bits clear. These registers can be addressed from any bank. PORTD, PORTE, TRISD and TRISE are not physically implemented on the 28-pin devices, read as `0'. 2000-2013 Microchip Technology Inc. DS30569C-page 13 PIC16F870/871 TABLE 2-1: Address SPECIAL FUNCTION REGISTER SUMMARY (CONTINUED) Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other RESETS(2) Bank 1 80h(4) INDF 81h OPTION_REG 82h(4) PCL 83h(4) STATUS Addressing this location uses contents of FSR to address data memory (not a physical register) RBPU INTEDG T0CS T0SE PS2 PS1 PS0 1111 1111 1111 1111 PD Z DC C 0001 1xxx 000q quuu Program Counter's (PC) Least Significant Byte IRP RP1 RP0 TO 0000 0000 0000 0000 PSA 0000 0000 0000 0000 84h(4) FSR 85h TRISA 86h TRISB PORTB Data Direction Register 87h TRISC PORTC Data Direction Register 1111 1111 1111 1111 88h(5) TRISD PORTD Data Direction Register 1111 1111 1111 1111 89h(5) TRISE IBF OBF IBOV 8Ah(1,4) PCLATH -- -- -- Indirect Data Memory Address Pointer -- -- xxxx xxxx uuuu uuuu PORTA Data Direction Register --11 1111 --11 1111 1111 1111 1111 1111 PSPMODE -- PORTE Data Direction Bits 0000 -111 0000 -111 Write Buffer for the upper 5 bits of the Program Counter ---0 0000 ---0 0000 8Bh(4) INTCON GIE PEIE T0IE INTE RBIE T0IF INTF RBIF 8Ch PIE1 PSPIE(3) ADIE RCIE TXIE -- CCP1IE TMR2IE TMR1IE 0000 -000 0000 -000 8Dh PIE2 -- -- -- EEIE -- -- -- -- ---0 ---- ---0 ---- 8Eh PCON -- -- -- -- -- -- POR BOR ---- --qq ---- --uu 0000 000x 0000 000u 8Fh -- Unimplemented -- -- 90h -- Unimplemented -- -- 91h -- Unimplemented -- -- 92h PR2 Timer2 Period Register 1111 1111 1111 1111 93h -- Unimplemented -- -- 94h -- Unimplemented -- -- 95h -- Unimplemented -- -- 96h -- Unimplemented -- -- 97h -- Unimplemented -- -- 98h TXSTA CSRC TX9 TXEN SYNC -- BRGH TRMT TX9D 99h SPBRG 9Ah -- Unimplemented -- -- 9Bh -- Unimplemented -- -- 9Ch -- Unimplemented -- -- 9Dh -- Unimplemented -- -- 9Eh ADRESL 9Fh ADCON1 Legend: Note 1: 2: 3: 4: 5: Baud Rate Generator Register 0000 -010 0000 -010 0000 0000 0000 0000 A/D Result Register Low Byte ADFM -- -- xxxx xxxx uuuu uuuu -- PCFG3 PCFG2 PCFG1 PCFG0 0--- 0000 0--- 0000 x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as '0', r = reserved. Shaded locations are unimplemented, read as `0'. The upper byte of the program counter is not directly accessible. PCLATH is a holding register for the PC<12:8> whose contents are transferred to the upper byte of the program counter. Other (non Power-up) Resets include external RESET through MCLR and Watchdog Timer Reset. Bits PSPIE and PSPIF are reserved on the 28-pin devices; always maintain these bits clear. These registers can be addressed from any bank. PORTD, PORTE, TRISD and TRISE are not physically implemented on the 28-pin devices, read as `0'. DS30569C-page 14 2000-2013 Microchip Technology Inc. PIC16F870/871 TABLE 2-1: Address SPECIAL FUNCTION REGISTER SUMMARY (CONTINUED) Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other RESETS(2) Bank 2 100h(4) INDF Addressing this location uses contents of FSR to address data memory (not a physical register) 0000 0000 0000 0000 101h TMR0 Timer0 Module's Register xxxx xxxx uuuu uuuu 102h(4) PCL Program Counter's (PC) Least Significant Byte 103h(4) STATUS 104h(4) FSR IRP RP1 RP0 0000 0000 0000 0000 TO PD Z DC C Indirect Data Memory Address Pointer 0001 1xxx 000q quuu xxxx xxxx uuuu uuuu 105h -- 106h PORTB 107h -- Unimplemented -- -- 108h -- Unimplemented -- -- 109h -- Unimplemented -- -- 10Ah(1,4) PCLATH Unimplemented -- PORTB Data Latch when written: PORTB pins when read -- -- -- GIE PEIE T0IE -- xxxx xxxx uuuu uuuu Write Buffer for the upper 5 bits of the Program Counter ---0 0000 ---0 0000 10Bh(4) INTCON 10Ch EEDATA EEPROM Data Register xxxx xxxx uuuu uuuu 10Dh EEADR EEPROM Address Register xxxx xxxx uuuu uuuu 10Eh EEDATH -- -- 10Fh EEADRH -- -- INTE RBIE T0IF INTF RBIF EEPROM Data Register High Byte -- 0000 000x 0000 000u xxxx xxxx uuuu uuuu EEPROM Address Register High Byte xxxx xxxx uuuu uuuu Bank 3 180h(4) INDF 181h OPTION_REG 182h(4) PCL 183h(4) STATUS 184h(4) FSR 185h Addressing this location uses contents of FSR to address data memory (not a physical register) INTEDG T0CS T0SE PSA PS2 PS1 PS0 PD Z DC C Program Counter's (PC) Least Significant Byte IRP RP1 RP0 TRISB 0000 0000 0000 0000 1111 1111 1111 1111 0000 0000 0000 0000 TO Indirect Data Memory Address Pointer -- 186h RBPU 0001 1xxx 000q quuu xxxx xxxx uuuu uuuu Unimplemented -- PORTB Data Direction Register -- 1111 1111 1111 1111 187h -- Unimplemented -- -- 188h -- Unimplemented -- -- 189h -- Unimplemented -- -- 18Ah(1,4) PCLATH 18Bh(4) 18Ch 18Dh EECON2 18Eh 18Fh Legend: Note 1: 2: 3: 4: 5: -- -- -- Write Buffer for the upper 5 bits of the Program Counter INTCON GIE PEIE T0IE INTE RBIE T0IF INTF RBIF 0000 000x 0000 000u EECON1 EEPGD -- -- -- WRERR WREN WR RD x--- x000 x--- u000 ---0 0000 ---0 0000 EEPROM Control Register2 (not a physical register) ---- ---- ---- ---- -- Reserved maintain clear 0000 0000 0000 0000 -- Reserved maintain clear 0000 0000 0000 0000 x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as '0', r = reserved. Shaded locations are unimplemented, read as `0'. The upper byte of the program counter is not directly accessible. PCLATH is a holding register for the PC<12:8> whose contents are transferred to the upper byte of the program counter. Other (non Power-up) Resets include external RESET through MCLR and Watchdog Timer Reset. Bits PSPIE and PSPIF are reserved on the 28-pin devices; always maintain these bits clear. These registers can be addressed from any bank. PORTD, PORTE, TRISD and TRISE are not physically implemented on the 28-pin devices, read as `0'. 2000-2013 Microchip Technology Inc. DS30569C-page 15 PIC16F870/871 2.2.2.1 STATUS Register The STATUS register contains the arithmetic status of the ALU, the RESET status and the bank select bits for data memory. The STATUS register can be the destination for any instruction, as with any other register. If the STATUS register is the destination for an instruction that affects the Z, DC or C bits, then the write to these three bits is disabled. These bits are set or cleared according to the device logic. Furthermore, the TO and PD bits are not writable, therefore, the result of an instruction with the STATUS register as destination may be different than intended. REGISTER 2-1: For example, CLRF STATUS will clear the upper three bits and set the Z bit. This leaves the STATUS register as 000u u1uu (where u = unchanged). It is recommended, therefore, that only BCF, BSF, SWAPF and MOVWF instructions are used to alter the STATUS register, because these instructions do not affect the Z, C or DC bits from the STATUS register. For other instructions not affecting any status bits, see the "Instruction Set Summary". Note 1: The C and DC bits operate as a borrow and digit borrow bit, respectively, in subtraction. See the SUBLW and SUBWF instructions for examples. STATUS REGISTER (ADDRESS: 03h, 83h, 103h, 183h) R/W-0 R/W-0 R/W-0 R-1 R-1 R/W-x R/W-x R/W-x IRP RP1 RP0 TO PD Z DC C bit 7 bit 0 bit 7-6 IRP: Register Bank Select bit (used for indirect addressing) 1 = Bank 2, 3 (100h - 1FFh) 0 = Bank 0, 1 (00h - FFh) bit 6-5 RP1:RP0: Register Bank Select bits (used for direct addressing) 11 = Bank 3 (180h - 1FFh) 10 = Bank 2 (100h - 17Fh) 11 = Bank 1 (80h - FFh) 10 = Bank 0 (00h - 7Fh) Each bank is 128 bytes. bit 4 TO: Time-out bit 1 = After power-up, CLRWDT instruction, or SLEEP instruction 0 = A WDT time-out occurred bit 3 PD: Power-down bit 1 = After power-up or by the CLRWDT instruction 0 = By execution of the SLEEP instruction bit 2 Z: Zero bit 1 = The result of an arithmetic or logic operation is zero 0 = The result of an arithmetic or logic operation is not zero bit 1 DC: Digit carry/borrow bit (ADDWF, ADDLW, SUBLW, SUBWF instructions) (for borrow, the polarity is reversed) 1 = A carry-out from the 4th low order bit of the result occurred 0 = No carry-out from the 4th low order bit of the result bit 0 C: Carry/borrow bit (ADDWF, ADDLW, SUBLW, SUBWF instructions) 1 = A carry-out from the Most Significant bit of the result occurred 0 = No carry-out from the Most Significant bit of the result occurred Note: For borrow, the polarity is reversed. A subtraction is executed by adding the two's complement of the second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high or low order bit of the source register. Legend: DS30569C-page 16 R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown 2000-2013 Microchip Technology Inc. PIC16F870/871 2.2.2.2 OPTION_REG Register The OPTION_REG register is a readable and writable register, which contains various control bits to configure the TMR0 prescaler/WDT postscaler (single assignable register known also as the prescaler), the External INT interrupt, TMR0 and the weak pull-ups on PORTB. Note: To achieve a 1:1 prescaler assignment for the TMR0 register, assign the prescaler to the Watchdog Timer. REGISTER 2-2: OPTION_REG REGISTER (ADDRESS: 81h,181h) R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 RBPU INTEDG T0CS T0SE PSA PS2 PS1 PS0 bit 7 bit 0 bit 7 RBPU: PORTB Pull-up Enable bit 1 = PORTB pull-ups are disabled 0 = PORTB pull-ups are enabled by individual port latch values bit 6 INTEDG: Interrupt Edge Select bit 1 = Interrupt on rising edge of RB0/INT pin 0 = Interrupt on falling edge of RB0/INT pin bit 5 T0CS: TMR0 Clock Source Select bit 1 = Transition on RA4/T0CKI pin 0 = Internal instruction cycle clock (CLKO) bit 4 T0SE: TMR0 Source Edge Select bit 1 = Increment on high-to-low transition on RA4/T0CKI pin 0 = Increment on low-to-high transition on RA4/T0CKI pin bit 3 PSA: Prescaler Assignment bit 1 = Prescaler is assigned to the WDT 0 = Prescaler is assigned to the Timer0 module bit 2-0 PS2:PS0: Prescaler Rate Select bits Bit Value 000 001 010 011 100 101 110 111 TMR0 Rate 1:2 1:4 1:8 1 : 16 1 : 32 1 : 64 1 : 128 1 : 256 WDT Rate 1:1 1:2 1:4 1:8 1 : 16 1 : 32 1 : 64 1 : 128 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared 2000-2013 Microchip Technology Inc. x = Bit is unknown DS30569C-page 17 PIC16F870/871 2.2.2.3 INTCON Register Note: The INTCON register is a readable and writable register, which contains various enable and flag bits for the TMR0 register overflow, RB Port change and External RB0/INT pin interrupts. REGISTER 2-3: Interrupt flag bits get set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit, GIE (INTCON<7>). User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. INTCON REGISTER (ADDRESS: 0Bh, 8Bh, 10Bh, 18Bh) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-x GIE PEIE T0IE INTE RBIE T0IF INTF RBIF bit 7 bit 0 bit 7 GIE: Global Interrupt Enable bit 1 = Enables all unmasked interrupts 0 = Disables all interrupts bit 6 PEIE: Peripheral Interrupt Enable bit 1 = Enables all unmasked peripheral interrupts 0 = Disables all peripheral interrupts bit 5 T0IE: TMR0 Overflow Interrupt Enable bit 1 = Enables the TMR0 interrupt 0 = Disables the TMR0 interrupt bit 4 INTE: RB0/INT External Interrupt Enable bit 1 = Enables the RB0/INT external interrupt 0 = Disables the RB0/INT external interrupt bit 3 RBIE: RB Port Change Interrupt Enable bit 1 = Enables the RB port change interrupt 0 = Disables the RB port change interrupt bit 2 T0IF: TMR0 Overflow Interrupt Flag bit 1 = TMR0 register has overflowed (must be cleared in software) 0 = TMR0 register did not overflow bit 1 INTF: RB0/INT External Interrupt Flag bit 1 = The RB0/INT external interrupt occurred (must be cleared in software) 0 = The RB0/INT external interrupt did not occur bit 0 RBIF: RB Port Change Interrupt Flag bit 1 = At least one of the RB7:RB4 pins changed state (must be cleared in software) 0 = None of the RB7:RB4 pins have changed state Legend: DS30569C-page 18 R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown 2000-2013 Microchip Technology Inc. PIC16F870/871 2.2.2.4 PIE1 Register The PIE1 register contains the individual enable bits for the peripheral interrupts. Note: Bit PEIE (INTCON<6>) must be set to enable any peripheral interrupt. REGISTER 2-4: PIE1 REGISTER (ADDRESS: 8Ch) R/W-0 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R/W-0 R/W-0 PSPIE(1) ADIE RCIE TXIE CCP1IE TMR2IE TMR1IE bit 7 bit 0 bit 7 PSPIE(1): Parallel Slave Port Read/Write Interrupt Enable bit 1 = Enables the PSP read/write interrupt 0 = Disables the PSP read/write interrupt bit 6 ADIE: A/D Converter Interrupt Enable bit 1 = Enables the A/D converter interrupt 0 = Disables the A/D converter interrupt bit 5 RCIE: USART Receive Interrupt Enable bit 1 = Enables the USART receive interrupt 0 = Disables the USART receive interrupt bit 4 TXIE: USART Transmit Interrupt Enable bit 1 = Enables the USART transmit interrupt 0 = Disables the USART transmit interrupt bit 3 Unimplemented: Read as `0' bit 2 CCP1IE: CCP1 Interrupt Enable bit 1 = Enables the CCP1 interrupt 0 = Disables the CCP1 interrupt bit 1 TMR2IE: TMR2 to PR2 Match Interrupt Enable bit 1 = Enables the TMR2 to PR2 match interrupt 0 = Disables the TMR2 to PR2 match interrupt bit 0 TMR1IE: TMR1 Overflow Interrupt Enable bit 1 = Enables the TMR1 overflow interrupt 0 = Disables the TMR1 overflow interrupt Note 1: PSPIE is reserved on the PIC16F870; always maintain this bit clear. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared 2000-2013 Microchip Technology Inc. x = Bit is unknown DS30569C-page 19 PIC16F870/871 2.2.2.5 PIR1 Register The PIR1 register contains the individual flag bits for the peripheral interrupts. Note: Interrupt flag bits get set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit, GIE (INTCON<7>). User software should ensure the appropriate interrupt bits are clear prior to enabling an interrupt. REGISTER 2-5: PIR1 REGISTER (ADDRESS: 0Ch) R/W-0 R/W-0 R-0 R-0 U-0 R/W-0 R/W-0 R/W-0 PSPIF(1) ADIF RCIF TXIF CCP1IF TMR2IF TMR1IF bit 7 bit 0 bit 7 PSPIF(1): Parallel Slave Port Read/Write Interrupt Flag bit 1 = A read or a write operation has taken place (must be cleared in software) 0 = No read or write has occurred bit 6 ADIF: A/D Converter Interrupt Flag bit 1 = An A/D conversion completed 0 = The A/D conversion is not complete bit 5 RCIF: USART Receive Interrupt Flag bit 1 = The USART receive buffer is full 0 = The USART receive buffer is empty bit 4 TXIF: USART Transmit Interrupt Flag bit 1 = The USART transmit buffer is empty 0 = The USART transmit buffer is full bit 3 Unimplemented: Read as `0' bit 2 CCP1IF: CCP1 Interrupt Flag bit Capture mode: 1 = A TMR1 register capture occurred (must be cleared in software) 0 = No TMR1 register capture occurred Compare mode: 1 = A TMR1 register compare match occurred (must be cleared in software) 0 = No TMR1 register compare match occurred PWM mode: Unused in this mode. bit 1 TMR2IF: TMR2 to PR2 Match Interrupt Flag bit 1 = TMR2 to PR2 match occurred (must be cleared in software) 0 = No TMR2 to PR2 match occurred bit 0 TMR1IF: TMR1 Overflow Interrupt Flag bit 1 = TMR1 register overflowed (must be cleared in software) 0 = TMR1 register did not overflow Note 1: PSPIF is reserved on the PIC16F870; always maintain this bit clear. Legend: DS30569C-page 20 R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown 2000-2013 Microchip Technology Inc. PIC16F870/871 2.2.2.6 PIE2 Register The PIE2 register contains the individual enable bit for the EEPROM write operation interrupt. REGISTER 2-6: PIE2 REGISTER (ADDRESS: 8Dh) U-0 U-0 U-0 R/W-0 U-0 U-0 U-0 U-0 -- -- -- EEIE -- -- -- -- bit 7 bit 0 bit 7-5 Unimplemented: Read as '0' bit 4 EEIE: EEPROM Write Operation Interrupt Enable bit 1 = Enable EE write interrupt 0 = Disable EE write interrupt bit 3-0 Unimplemented: Read as '0' Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared 2000-2013 Microchip Technology Inc. x = Bit is unknown DS30569C-page 21 PIC16F870/871 2.2.2.7 PIR2 Register The PIR2 register contains the flag bit for the EEPROM write operation interrupt. . Note: Interrupt flag bits get set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit, GIE (INTCON<7>). User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. REGISTER 2-7: PIR2 REGISTER (ADDRESS: 0Dh) U-0 U-0 U-0 R/W-0 U-0 U-0 U-0 U-0 -- -- -- EEIF -- -- -- -- bit 7 bit 0 bit 7-5 Unimplemented: Read as '0' bit 4 EEIF: EEPROM Write Operation Interrupt Flag bit 1 = The write operation completed (must be cleared in software) 0 = The write operation is not complete or has not been started bit 3-0 Unimplemented: Read as '0' Legend: DS30569C-page 22 R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown 2000-2013 Microchip Technology Inc. PIC16F870/871 2.2.2.8 PCON Register The Power Control (PCON) register contains flag bits to allow differentiation between a Power-on Reset (POR), a Brown-out Reset (BOR), a Watchdog Reset (WDT) and an external MCLR Reset. Note: BOR is unknown on POR. It must be set by the user and checked on subsequent RESETS to see if BOR is clear, indicating a brown-out has occurred. The BOR status bit is a don't care and is not predictable if the brown-out circuit is disabled (by clearing the BOREN bit in the configuration word). REGISTER 2-8: PCON REGISTER (ADDRESS: 8Eh) U-0 U-0 U-0 U-0 U-0 U-0 R/W-0 R/W-1 -- -- -- -- -- -- POR BOR bit 7 bit 0 bit 7-2 Unimplemented: Read as '0' bit 1 POR: Power-on Reset Status bit 1 = No Power-on Reset occurred 0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs) bit 0 BOR: Brown-out Reset Status bit 1 = No Brown-out Reset occurred 0 = A Brown-out Reset occurred (must be set in software after a Brown-out Reset occurs) Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared 2000-2013 Microchip Technology Inc. x = Bit is unknown DS30569C-page 23 PIC16F870/871 2.3 PCL and PCLATH The Program Counter (PC) is 13-bits wide. The low byte comes from the PCL register, which is a readable and writable register. The upper bits (PC<12:8>) are not readable, but are indirectly writable through the PCLATH register. On any RESET, the upper bits of the PC will be cleared. Figure 2-3 shows the two situations for the loading of the PC. The upper example in the figure shows how the PC is loaded on a write to PCL (PCLATH<4:0> PCH). The lower example in the figure shows how the PC is loaded during a CALL or GOTO instruction (PCLATH<4:3> PCH). FIGURE 2-3: LOADING OF PC IN DIFFERENT SITUATIONS PCH PCL 12 8 7 0 PC 8 PCLATH<4:0> 5 Instruction with PCL as Destination ALU PCLATH PCH 12 11 10 PCL 8 0 7 PC GOTO,CALL 2 PCLATH<4:3> 11 Opcode <10:0> PCLATH 2.3.1 COMPUTED GOTO A computed GOTO is accomplished by adding an offset to the program counter (ADDWF PCL). When doing a table read using a computed GOTO method, care should be exercised if the table location crosses a PCL memory boundary (each 256-byte block). Refer to the application note, "Implementing a Table Read" (AN556). 2.3.2 STACK The PIC16FXXX family has an 8-level deep x 13-bit wide hardware stack. The stack space is not part of either program or data space and the stack pointer is not readable or writable. The PC is PUSHed onto the stack when a CALL instruction is executed, or an interrupt causes a branch. The stack is POPed in the event of a RETURN, RETLW or a RETFIE instruction execution. PCLATH is not affected by a PUSH or POP operation. DS30569C-page 24 The stack operates as a circular buffer. This means that after the stack has been PUSHed eight times, the ninth push overwrites the value that was stored from the first push. The tenth push overwrites the second push (and so on). Note 1: There are no status bits to indicate stack overflow or stack underflow conditions. 2: There are no instructions/mnemonics called PUSH or POP. These are actions that occur from the execution of the CALL, RETURN, RETLW and RETFIE instructions, or the vectoring to an interrupt address. 2.4 Program Memory Paging The PIC16FXXX architecture is capable of addressing a continuous 8K word block of program memory. The CALL and GOTO instructions provide 11 bits of the address, which allows branches within any 2K program memory page. Therefore, the 8K words of program memory are broken into four pages. Since the PIC16F872 has only 2K words of program memory or one page, additional code is not required to ensure that the correct page is selected before a CALL or GOTO instruction is executed. The PCLATH<4:3> bits should always be maintained as zeros. If a return from a CALL instruction (or interrupt) is executed, the entire 13-bit PC is popped off the stack. Manipulation of the PCLATH is not required for the return instructions. 2.5 Indirect Addressing, INDF and FSR Registers The INDF register is not a physical register. Addressing the INDF register will cause indirect addressing. Indirect addressing is possible by using the INDF register. Any instruction using the INDF register actually accesses the register pointed to by the File Select register, FSR. Reading the INDF register itself indirectly (FSR = 0) will read 00h. Writing to the INDF register indirectly results in a no operation (although status bits may be affected). An effective 9-bit address is obtained by concatenating the 8-bit FSR register and the IRP bit (STATUS<7>), as shown in Figure 2-4. A simple program to clear RAM locations 20h-2Fh using indirect addressing is shown in Example 2-1. EXAMPLE 2-1: movlw movwf NEXT clrf incf btfss goto CONTINUE : INDIRECT ADDRESSING 0x20 FSR INDF FSR,F FSR,4 NEXT ;initialize pointer ;to RAM ;clear INDF register ;inc pointer ;all done? ;no clear next ;yes continue 2000-2013 Microchip Technology Inc. PIC16F870/871 FIGURE 2-4: DIRECT/INDIRECT ADDRESSING Direct Addressing Indirect Addressing from opcode RP1: RP0 6 Bank Select Location Select 0 IRP 7 Bank Select 00 01 10 FSR Register 0 Location Select 11 00h 80h 100h 180h 7Fh FFh 17Fh 1FFh Data Memory(1) Bank 0 Note 1: Bank 1 Bank 2 Bank 3 For register file map detail see Figure 2-2. 2000-2013 Microchip Technology Inc. DS30569C-page 25 PIC16F870/871 NOTES: DS30569C-page 26 2000-2013 Microchip Technology Inc. PIC16F870/871 3.0 DATA EEPROM AND FLASH PROGRAM MEMORY The Data EEPROM and FLASH Program Memory are readable and writable during normal operation over the entire VDD range. A bulk erase operation may not be issued from user code (which includes removing code protection). The data memory is not directly mapped in the register file space. Instead, it is indirectly addressed through the Special Function Registers (SFR). There are six SFRs used to read and write the program and data EEPROM memory. These registers are: * * * * * * EECON1 EECON2 EEDATA EEDATH EEADR EEADRH The EEPROM data memory allows byte read and write. When interfacing to the data memory block, EEDATA holds the 8-bit data for read/write and EEADR holds the address of the EEPROM location being accessed. The registers EEDATH and EEADRH are not used for data EEPROM access. The PIC16F870/871 devices have 64 bytes of data EEPROM with an address range from 0h to 3Fh. The value written to program memory does not need to be a valid instruction. Therefore, up to 14-bit numbers can be stored in memory for use as calibration parameters, serial numbers, packed 7-bit ASCII, etc. Executing a program memory location containing data that forms an invalid instruction results in a NOP. 3.1 EEADR The address registers can address up to a maximum of 256 bytes of data EEPROM or up to a maximum of 8K words of program FLASH. However, the PIC16F870/871 have 64 bytes of data EEPROM and 2K words of program FLASH. When selecting a program address value, the MSByte of the address is written to the EEADRH register and the LSByte is written to the EEADR register. When selecting a data address value, only the LSByte of the address is written to the EEADR register. On the PIC16F870/871 devices, the upper two bits of the EEADR must always be cleared to prevent inadvertent access to the wrong location in data EEPROM. This also applies to the program memory. The upper five MSbits of EEADRH must always be clear during program FLASH access. 3.2 EECON1 and EECON2 Registers The EEPROM data memory is rated for high erase/ write cycles. The write time is controlled by an on-chip timer. The write time will vary with voltage and temperature, as well as from chip-to-chip. Please refer to the specifications for exact limits. The EECON1 register is the control register for configuring and initiating the access. The EECON2 register is not a physically implemented register, but is used exclusively in the memory write sequence to prevent inadvertent writes. The program memory allows word reads and writes. Program memory access allows for checksum calculation and calibration table storage. A byte or word write automatically erases the location and writes the new data (erase before write). Writing to program memory will cease operation until the write is complete. The program memory cannot be accessed during the write, therefore code cannot execute. During the write operation, the oscillator continues to clock the peripherals, and therefore, they continue to operate. Interrupt events will be detected and essentially "queued" until the write is completed. When the write completes, the next instruction in the pipeline is executed and the branch to the interrupt vector address will occur. There are many bits used to control the read and write operations to EEPROM data and FLASH program memory. The EEPGD bit determines if the access will be a program or data memory access. When clear, any subsequent operations will work on the EEPROM data memory. When set, all subsequent operations will operate in the program memory. When interfacing to the program memory block, the EEDATH:EEDATA registers form a two-byte word, which holds the 14-bit data for read/write. The EEADRH:EEADR registers form a two-byte word, which holds the 13-bit address of the FLASH location being accessed. The PIC16F870/871 devices have 2K words of program FLASH with an address range from 0h to 7FFh. The unused upper bits in both the EEDATH and EEDATA registers all read as `0's. 2000-2013 Microchip Technology Inc. Read operations only use one additional bit, RD, which initiates the read operation from the desired memory location. Once this bit is set, the value of the desired memory location will be available in the data registers. This bit cannot be cleared by firmware. It is automatically cleared at the end of the read operation. For EEPROM data memory reads, the data will be available in the EEDATA register in the very next instruction cycle after the RD bit is set. For program memory reads, the data will be loaded into the EEDATH:EEDATA registers, following the second instruction after the RD bit is set. DS30569C-page 27 PIC16F870/871 Write operations have two control bits, WR and WREN, and two status bits, WRERR and EEIF. The WREN bit is used to enable or disable the write operation. When WREN is clear, the write operation will be disabled. Therefore, the WREN bit must be set before executing a write operation. The WR bit is used to initiate the write operation. It also is automatically cleared at the end of the write operation. The interrupt flag EEIF is used to determine when the memory write completes. This flag must be cleared in software before setting the WR bit. For EEPROM data memory, once the WREN bit and the WR bit have been set, the desired memory address in EEADR will be erased, followed by a write of the data in EEDATA. This operation takes place in parallel with the microcontroller continuing to execute normally. When the write is complete, the EEIF flag bit will be set. For program memory, once the WREN bit and the WR bit have been set, the microcontroller will cease to exe- REGISTER 3-1: cute instructions. The desired memory location pointed to by EEADRH:EEADR will be erased. Then, the data value in EEDATH:EEDATA will be programmed. When complete, the EEIF flag bit will be set and the microcontroller will continue to execute code. The WRERR bit is used to indicate when the PIC16F870/871 devices have been reset during a write operation. WRERR should be cleared after Power-on Reset. Thereafter, it should be checked on any other RESET. The WRERR bit is set when a write operation is interrupted by a MCLR Reset, or a WDT Time-out Reset, during normal operation. In these situations, following a RESET, the user should check the WRERR bit and rewrite the memory location, if set. The contents of the data registers, address registers and EEPGD bit are not affected by either MCLR Reset, or WDT Time-out Reset, during normal operation. EECON1 REGISTER (ADDRESS: 18Ch) R/W-x U-0 U-0 U-0 R/W-x R/W-0 R/S-0 R/S-0 EEPGD -- -- -- WRERR WREN WR RD bit 7 bit 0 bit 7 EEPGD: Program/Data EEPROM Select bit 1 = Accesses program memory 0 = Accesses data memory (This bit cannot be changed while a read or write operation is in progress.) bit 6-4 Unimplemented: Read as '0' bit 3 WRERR: EEPROM Error Flag bit 1 = A write operation is prematurely terminated (any MCLR Reset or any WDT Reset during normal operation) 0 = The write operation completed bit 2 WREN: EEPROM Write Enable bit 1 = Allows write cycles 0 = Inhibits write to the EEPROM bit 1 WR: Write Control bit 1 = Initiates a write cycle. (The bit is cleared by hardware once write is complete. The WR bit can only be set (not cleared) in software.) 0 = Write cycle to the EEPROM is complete bit 0 RD: Read Control bit 1 = Initiates an EEPROM read. (RD is cleared in hardware. The RD bit can only be set (not cleared) in software.) 0 = Does not initiate an EEPROM read Legend: DS30569C-page 28 R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR '1' = Bit is set '0' = Bit is cleared x = Bit is unknown 2000-2013 Microchip Technology Inc. PIC16F870/871 3.3 Reading the EEPROM Data Memory Reading EEPROM data memory only requires that the desired address to access be written to the EEADR register and clear the EEPGD bit. After the RD bit is set, data will be available in the EEDATA register on the very next instruction cycle. EEDATA will hold this value until another read operation is initiated or until it is written by firmware. The steps to reading the EEPROM data memory are: 1. 2. 3. 4. Write the address to EEDATA. Make sure that the address is not larger than the memory size of the PIC16F870/871 devices. Clear the EEPGD bit to point to EEPROM data memory. Set the RD bit to start the read operation. Read the data from the EEDATA register. EXAMPLE 3-1: EEPROM DATA READ BSF BCF MOVF MOVWF BSF BCF BSF BCF STATUS, STATUS, ADDR, W EEADR STATUS, EECON1, EECON1, STATUS, RP1 RP0 MOVF EEDATA, W RP0 EEPGD RD RP0 ; ;Bank 2 ;Write address ;to read from ;Bank 3 ;Point to Data memory ;Start read operation ;Bank 2 The steps to write to EEPROM data memory are: 1. If step 10 is not implemented, check the WR bit to see if a write is in progress. 2. Write the address to EEADR. Make sure that the address is not larger than the memory size of the PIC16F870/871 devices. 3. Write the 8-bit data value to be programmed in the EEDATA register. 4. Clear the EEPGD bit to point to EEPROM data memory. 5. Set the WREN bit to enable program operations. 6. Disable interrupts (if enabled). 7. Execute the special five instruction sequence: * Write 55h to EECON2 in two steps (first to W, then to EECON2) * Write AAh to EECON2 in two steps (first to W, then to EECON2) * Set the WR bit 8. Enable interrupts (if using interrupts). 9. Clear the WREN bit to disable program operations. 10. At the completion of the write cycle, the WR bit is cleared and the EEIF interrupt flag bit is set. (EEIF must be cleared by firmware.) If step 1 is not implemented, then firmware should check for EEIF to be set, or WR to clear, to indicate the end of the program cycle. ;W = EEDATA EXAMPLE 3-2: 3.4 Writing to the EEPROM Data Memory There are many steps in writing to the EEPROM data memory. Both address and data values must be written to the SFRs. The EEPGD bit must be cleared, and the WREN bit must be set, to enable writes. The WREN bit should be kept clear at all times, except when writing to the EEPROM data. The WR bit can only be set if the WREN bit was set in a previous operation (i.e., they both cannot be set in the same operation). The WREN bit should then be cleared by firmware after the write. Clearing the WREN bit before the write actually completes will not terminate the write in progress. Writes to EEPROM data memory must also be prefaced with a special sequence of instructions that prevent inadvertent write operations. This is a sequence of five instructions that must be executed without interruptions. The firmware should verify that a write is not in progress before starting another cycle. 2000-2013 Microchip Technology Inc. EEPROM DATA WRITE BSF STATUS, RP1 ; BSF STATUS, RP0 ;Bank 3 BTFSC EECON1, WR ;Wait for GOTO $-1 ;write to finish BCF STATUS, RP0 ;Bank 2 MOVF ADDR, W ;Address to MOVWF EEADR ;write to MOVF VALUE, W ;Data to MOVWF EEDATA ;write BSF STATUS, RP0 ;Bank 3 BCF EECON1, EEPGD ;Point to Data memory BSF EECON1, WREN ;Enable writes ;Only disable interrupts BCF INTCON, GIE ;if already enabled, ;otherwise discard MOVLW 0x55 ;Write 55h to MOVWF EECON2 ;EECON2 MOVLW 0xAA ;Write AAh to MOVWF EECON2 ;EECON2 BSF EECON1, WR ;Start write operation ;Only enable interrupts BSF INTCON, GIE ;if using interrupts, ;otherwise discard BCF EECON1, WREN ;Disable writes DS30569C-page 29 PIC16F870/871 3.5 Reading the FLASH Program Memory 3.6 Writing to the FLASH Program Memory Reading FLASH program memory is much like that of EEPROM data memory, only two NOP instructions must be inserted after the RD bit is set. These two instruction cycles that the NOP instructions execute, will be used by the microcontroller to read the data out of program memory and insert the value into the EEDATH:EEDATA registers. Data will be available following the second NOP instruction. EEDATH and EEDATA will hold their value until another read operation is initiated, or until they are written by firmware. Writing to FLASH program memory is unique, in that the microcontroller does not execute instructions while programming is taking place. The oscillator continues to run and all peripherals continue to operate and queue interrupts, if enabled. Once the write operation completes (specification D133), the processor begins executing code from where it left off. The other important difference when writing to FLASH program memory is that the WRT configuration bit, when clear, prevents any writes to program memory (see Table 3-1). The steps to reading the FLASH program memory are: Just like EEPROM data memory, there are many steps in writing to the FLASH program memory. Both address and data values must be written to the SFRs. The EEPGD bit must be set, and the WREN bit must be set to enable writes. The WREN bit should be kept clear at all times, except when writing to the FLASH program memory. The WR bit can only be set if the WREN bit was set in a previous operation (i.e., they both cannot be set in the same operation). The WREN bit should then be cleared by firmware after the write. Clearing the WREN bit before the write actually completes will not terminate the write in progress. 1. 2. 3. 4. 5. Write the address to EEADRH:EEADR. Make sure that the address is not larger than the memory size of the PIC16F870/871 devices. Set the EEPGD bit to point to FLASH program memory. Set the RD bit to start the read operation. Execute two NOP instructions to allow the microcontroller to read out of program memory. Read the data from the EEDATH:EEDATA registers. EXAMPLE 3-3: BSF BCF MOVF MOVWF MOVF MOVWF BSF BSF BSF NOP NOP BCF MOVF MOVWF MOVF MOVWF FLASH PROGRAM READ STATUS, RP1 STATUS, RP0 ADDRL, W EEADR ADDRH,W EEADRH STATUS, RP0 EECON1, EEPGD EECON1, RD STATUS, RP0 EEDATA, W DATAL EEDATH,W DATAH ; ;Bank 2 ;Write the ;address bytes ;for the desired ;address to read ;Bank 3 ;Point to Program memory ;Start read operation ;Required two NOPs ; ;Bank 2 ;DATAL = EEDATA ; ;DATAH = EEDATH ; Writes to program memory must also be prefaced with a special sequence of instructions that prevent inadvertent write operations. This is a sequence of five instructions that must be executed without interruption for each byte written. These instructions must then be followed by two NOP instructions to allow the microcontroller to setup for the write operation. Once the write is complete, the execution of instructions starts with the instruction after the second NOP. The steps to write to program memory are: 1. 2. 3. 4. 5. 6. 7. 8. 9. DS30569C-page 30 Write the address to EEADRH:EEADR. Make sure that the address is not larger than the memory size of the PIC16F870/871 devices. Write the 14-bit data value to be programmed in the EEDATH:EEDATA registers. Set the EEPGD bit to point to FLASH program memory. Set the WREN bit to enable program operations. Disable interrupts (if enabled). Execute the special five instruction sequence: * Write 55h to EECON2 in two steps (first to W, then to EECON2) * Write AAh to EECON2 in two steps (first to W, then to EECON2) * Set the WR bit Execute two NOP instructions to allow the microcontroller to setup for write operation. Enable interrupts (if using interrupts). Clear the WREN bit to disable program operations. 2000-2013 Microchip Technology Inc. PIC16F870/871 At the completion of the write cycle, the WR bit is cleared and the EEIF interrupt flag bit is set. (EEIF must be cleared by firmware.) Since the microcontroller does not execute instructions during the write cycle, the firmware does not necessarily have to check either EEIF, or WR, to determine if the write had finished. EXAMPLE 3-4: FLASH PROGRAM WRITE BSF BCF MOVF MOVWF MOVF MOVWF MOVF MOVWF MOVF MOVWF BSF BSF BSF STATUS, RP1 STATUS, RP0 ADDRL, W EEADR ADDRH, W EEADRH VALUEL, W EEDATA VALUEH, W EEDATH STATUS, RP0 EECON1, EEPGD EECON1, WREN BCF INTCON, GIE MOVLW MOVWF MOVLW MOVWF BSF NOP NOP 0x55 EECON2 0xAA EECON2 EECON1, WR BSF INTCON, GIE BCF EECON1, WREN 3.7 ; ;Bank 2 ;Write address ;of desired ;program memory ;location ;Write value to ;program at ;desired memory ;location ;Bank 3 ;Point to Program memory ;Enable writes ;Only disable interrupts ;if already enabled, ;otherwise discard ;Write 55h to ;EECON2 ;Write AAh to ;EECON2 ;Start write operation ;Two NOPs to allow micro ;to setup for write ;Only enable interrupts ;if using interrupts, ;otherwise discard ;Disable writes Write Verify The PIC16F870/871 devices do not automatically verify the value written during a write operation. Depending on the application, good programming practice may dictate that the value written to memory be verified against the original value. This should be used in applications where excessive writes can stress bits near the specified endurance limits. 2000-2013 Microchip Technology Inc. 3.8 Protection Against Spurious Writes There are conditions when the device may not want to write to the EEPROM data memory or FLASH program memory. To protect against these spurious write conditions, various mechanisms have been built into the PIC16F870/871 devices. On power-up, the WREN bit is cleared and the Power-up Timer (if enabled) prevents writes. The write initiate sequence and the WREN bit together, help prevent any accidental writes during brown-out, power glitches, or firmware malfunction. 3.9 Operation While Code Protected The PIC16F870/871 devices have two code protect mechanisms, one bit for EEPROM data memory and two bits for FLASH program memory. Data can be read and written to the EEPROM data memory, regardless of the state of the code protection bit, CPD. When code protection is enabled and CPD cleared, external access via ICSP is disabled, regardless of the state of the program memory code protect bits. This prevents the contents of EEPROM data memory from being read out of the device. The state of the program memory code protect bits, CP0 and CP1, do not affect the execution of instructions out of program memory. The PIC16F870/871 devices can always read the values in program memory, regardless of the state of the code protect bits. However, the state of the code protect bits and the WRT bit will have different effects on writing to program memory. Table 4-1 shows the effect of the code protect bits and the WRT bit on program memory. Once code protection has been enabled for either EEPROM data memory or FLASH program memory, only a full erase of the entire device will disable code protection. DS30569C-page 31 PIC16F870/871 3.10 FLASH Program Memory Write Protection The configuration word contains a bit that write protects the FLASH program memory, called WRT. This bit can only be accessed when programming the PIC16F870/871 devices via ICSP. Once write protection is enabled, only an erase of the entire device will disable it. When enabled, write protection prevents any writes to FLASH program memory. Write protection does not affect program memory reads. TABLE 3-1: READ/WRITE STATE OF INTERNAL FLASH PROGRAM MEMORY Configuration Bits Internal Read Memory Location Internal Write ICSP Read ICSP Write CP1 CP0 WRT 0 0 x All program memory Yes No No No 0 1 0 Unprotected areas Yes No Yes No 0 1 0 Protected areas Yes No No No 0 1 1 Unprotected areas Yes Yes Yes No 0 1 1 Protected areas Yes No No No 1 0 0 Unprotected areas Yes No Yes No 1 0 0 Protected areas Yes No No No 1 0 1 Unprotected areas Yes Yes Yes No 1 0 1 Protected areas Yes No No No 1 1 0 All program memory Yes No Yes Yes 1 1 1 All program memory Yes Yes Yes Yes TABLE 3-2: REGISTERS ASSOCIATED WITH DATA EEPROM/PROGRAM FLASH Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other RESETS 0Bh, 8Bh, INTCON 10Bh, 18Bh GIE PEIE T0IE INTE RBIE T0IF INTF RBIF 0000 000x 0000 000u xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu Address 10Dh EEADR 10Fh EEADRH 10Ch EEDATA 10Eh EEDATH -- -- 18Ch EECON1 EEPGD -- 18Dh EECON2 EEPROM Control Register2 (not a physical register) Legend: Note 1: EEPROM Address Register, Low Byte -- -- -- EEPROM Address, High Byte EEPROM Data Register, Low Byte EEPROM Data Register, High Byte -- -- WRERR WREN WR RD xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu x--- x000 x--- u000 -- -- x = unknown, u = unchanged, r = reserved, - = unimplemented, read as '0'. Shaded cells are not used during FLASH/EEPROM access. These bits are reserved; always maintain these bits clear. DS30569C-page 32 2000-2013 Microchip Technology Inc. PIC16F870/871 4.0 I/O PORTS FIGURE 4-1: Some pins for these I/O ports are multiplexed with an alternate function for the peripheral features on the device. In general, when a peripheral is enabled, that pin may not be used as a general purpose I/O pin. Additional information on I/O ports may be found in the PIC(R) Mid-Range MCU Family Reference Manual (DS33023). 4.1 Data Bus D Q VDD WR Port Q CK P Data Latch PORTA and the TRISA Register PORTA is a 6-bit wide bi-directional port. The corresponding data direction register is TRISA. Setting a TRISA bit (= 1) will make the corresponding PORTA pin an input (i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISA bit (= 0) will make the corresponding PORTA pin an output (i.e., put the contents of the output latch on the selected pin). BLOCK DIAGRAM OF RA3:RA0 AND RA5 PINS D WR TRIS N Q VSS Analog Input Mode Q CK TRIS Latch Other PORTA pins are multiplexed with analog inputs and analog VREF input. The operation of each pin is selected by clearing/setting the control bits in the ADCON1 register (A/D Control Register 1). Note: On a Power-on Reset, these pins are configured as analog inputs and read as '0'. The TRISA register controls the direction of the RA pins, even when they are being used as analog inputs. The user must ensure the bits in the TRISA register are maintained set when using them as analog inputs. EXAMPLE 4-1: BCF BCF CLRF BSF MOVLW MOVWF MOVLW MOVWF STATUS, RP0 0x06 ADCON1 0xCF TRISA Q ; ;Bank0 ;Initialize PORTA by ;clearing output ;data latches ;Select Bank 1 ;Configure all pins ;as digital inputs ;Value used to ;initialize data ;direction ;Set RA<3:0> as ;inputs ;RA<5:4> as outputs ;TRISA<7:6> are ;always read as '0'. 2000-2013 Microchip Technology Inc. D EN RD PORT To A/D Converter Note 1: I/O pins have protection diodes to VDD and VSS. FIGURE 4-2: Data Bus WR PORT BLOCK DIAGRAM OF RA4/T0CKI PIN D Q CK Q N Data Latch WR TRIS INITIALIZING PORTA STATUS, RP0 STATUS, RP1 PORTA TTL Input Buffer RD TRIS Reading the PORTA register reads the status of the pins, whereas writing to it will write to the port latch. All write operations are read-modify-write operations. Therefore, a write to a port implies that the port pins are read, the value is modified and then written to the port data latch. Pin RA4 is multiplexed with the Timer0 module clock input to become the RA4/T0CKI pin. The RA4/T0CKI pin is a Schmitt Trigger input and an open drain output. All other PORTA pins have TTL input levels and full CMOS output drivers. I/O pin(1) D Q CK Q I/O pin(1) VSS Schmitt Trigger Input Buffer TRIS Latch RD TRIS Q D ENEN RD PORT TMR0 Clock Input Note 1: I/O pin has protection diodes to VSS only. DS30569C-page 33 PIC16F870/871 TABLE 4-1: PORTA FUNCTIONS Name Bit# Buffer Function RA0/AN0 bit0 TTL Input/output or analog input. RA1/AN1 bit1 TTL Input/output or analog input. RA2/AN2 bit2 TTL Input/output or analog input. RA3/AN3/VREF bit3 TTL Input/output or analog input or VREF. RA4/T0CKI bit4 ST Input/output or external clock input for Timer0. Output is open drain type. RA5/AN4 bit5 TTL Input/output or analog input. Legend: TTL = TTL input, ST = Schmitt Trigger input TABLE 4-2: Address SUMMARY OF REGISTERS ASSOCIATED WITH PORTA Name Bit 7 Bit 6 05h PORTA -- -- 85h TRISA -- -- 9Fh ADCON1 ADFM Legend: -- Value on all other RESETS Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR RA5 RA4 RA3 RA2 RA1 RA0 --0x 0000 --0u 0000 PORTA Data Direction Register -- -- --11 1111 --11 1111 PCFG3 PCFG2 PCFG1 PCFG0 --0- 0000 --0- 0000 x = unknown, u = unchanged, - = unimplemented locations read as '0'. Shaded cells are not used by PORTA. DS30569C-page 34 2000-2013 Microchip Technology Inc. PIC16F870/871 4.2 PORTB and the TRISB Register PORTB is an 8-bit wide, bi-directional port. The corresponding data direction register is TRISB. Setting a TRISB bit (= 1) will make the corresponding PORTB pin an input (i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISB bit (= 0) will make the corresponding PORTB pin an output (i.e., put the contents of the output latch on the selected pin). Three pins of PORTB are multiplexed with the Low Voltage Programming function: RB3/PGM, RB6/PGC and RB7/PGD. The alternate functions of these pins are described in the Special Features Section. Each of the PORTB pins has a weak internal pull-up. A single control bit can turn on all the pull-ups. This is performed by clearing bit RBPU (OPTION_REG<7>). The weak pull-up is automatically turned off when the port pin is configured as an output. The pull-ups are disabled on a Power-on Reset. FIGURE 4-3: BLOCK DIAGRAM OF RB3:RB0 PINS Data Bus WR Port Weak P Pull-up Data Latch D Q b) Any read or write of PORTB. This will end the mismatch condition. Clear flag bit RBIF. A mismatch condition will continue to set flag bit RBIF. Reading PORTB will end the mismatch condition and allow flag bit RBIF to be cleared. The interrupt-on-change feature is recommended for wake-up on key depression operation and operations where PORTB is only used for the interrupt-on-change feature. Polling of PORTB is not recommended while using the interrupt-on-change feature. This interrupt on mismatch feature, together with software configurable pull-ups on these four pins, allow easy interface to a keypad and make it possible for wake-up on key-depression. Refer to the Embedded Control Handbook, "Implementing Wake-up on Key Stroke" (AN552). RB0/INT is discussed in detail in Section 11.10.1. FIGURE 4-4: I/O BLOCK DIAGRAM OF RB7:RB4 PINS pin(1) CK VDD RBPU(2) TRIS Latch D Q WR TRIS a) RB0/INT is an external interrupt input pin and is configured using the INTEDG bit (OPTION_REG<6>). VDD RBPU(2) This interrupt can wake the device from SLEEP. The user, in the Interrupt Service Routine, can clear the interrupt in the following manner: TTL Input Buffer CK Weak P Pull-up Data Latch Data Bus D Q I/O pin(1) WR Port CK TRIS Latch RD TRIS D Q WR TRIS RD Port TTL Input Buffer CK EN RB0/INT RB3/PGM RD TRIS Schmitt Trigger Buffer Note 1: 2: Q D I/O pins have diode protection to VDD and VSS. To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (OPTION_REG<7>). Four of PORTB's pins, RB7:RB4, have an interrupt-onchange feature. Only pins configured as inputs can cause this interrupt to occur (i.e., any RB7:RB4 pin configured as an output is excluded from the interrupton-change comparison). The input pins (of RB7:RB4) are compared with the old value latched on the last read of PORTB. The "mismatch" outputs of RB7:RB4 are OR'ed together to generate the RB Port Change Interrupt with flag bit RBIF (INTCON<0>). 2000-2013 Microchip Technology Inc. Latch Q RD Port From other RB7:RB4 pins D EN RD Port Set RBIF ST Buffer Q Q1 D RD Port EN Q3 RB7:RB6 in Serial Programming Mode Note 1: 2: I/O pins have diode protection to VDD and VSS. To enable weak pull-ups, set the appropriate TRIS bit(s) and clear the RBPU bit (OPTION_REG<7>). DS30569C-page 35 PIC16F870/871 TABLE 4-3: Name PORTB FUNCTIONS Bit# Buffer (1) Function RB0/INT bit0 TTL/ST RB1 bit1 TTL RB2 bit2 TTL RB3/PGM bit3 TTL/ST(1) RB4 bit4 TTL Input/output pin (with interrupt-on-change). Internal software programmable weak pull-up. RB5 bit5 TTL Input/output pin (with interrupt-on-change). Internal software programmable weak pull-up. RB6/PGC bit6 TTL/ST(2) Input/output pin (with interrupt-on-change) or In-Circuit Debugger pin. Internal software programmable weak pull-up. Serial programming clock. RB7/PGD bit7 TTL/ST(2) Input/output pin (with interrupt-on-change) or In-Circuit Debugger pin. Internal software programmable weak pull-up. Serial programming data. Legend: Note 1: 2: Input/output pin. Internal software programmable weak pull-up. Input/output pin. Internal software programmable weak pull-up. Input/output pin or programming pin in LVP mode. Internal software programmable weak pull-up. TTL = TTL input, ST = Schmitt Trigger input This buffer is a Schmitt Trigger input when configured as the external interrupt or LVP mode. This buffer is a Schmitt Trigger input when used in Serial Programming mode. TABLE 4-4: Address SUMMARY OF REGISTERS ASSOCIATED WITH PORTB Name 06h, 106h PORTB 86h, 186h TRISB 81h, 181h OPTION_REG Legend: Input/output pin or external interrupt input. Internal software programmable weak pull-up. Value on all other RESETS Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0 xxxx xxxx uuuu uuuu T0SE PSA PS2 PS1 PS0 PORTB Data Direction Register RBPU INTEDG T0CS 1111 1111 1111 1111 1111 1111 1111 1111 x = unknown, u = unchanged. Shaded cells are not used by PORTB. DS30569C-page 36 2000-2013 Microchip Technology Inc. PIC16F870/871 4.3 FIGURE 4-5: PORTC and the TRISC Register PORTC is an 8-bit wide, bi-directional port. The corresponding data direction register is TRISC. Setting a TRISC bit (= 1) will make the corresponding PORTC pin an input (i.e., put the corresponding output driver in a Hi-Impedance mode). Clearing a TRISC bit (= 0) will make the corresponding PORTC pin an output (i.e., put the contents of the output latch on the selected pin). PORTC BLOCK DIAGRAM (PERIPHERAL OUTPUT OVERRIDE) Port/Peripheral Select(2) Peripheral Data Out Data Bus WR PORT PORTC is multiplexed with several peripheral functions (Table 4-5). PORTC pins have Schmitt Trigger input buffers. VDD 0 D Q P 1 CK Q Data Latch WR TRIS When enabling peripheral functions, care should be taken in defining TRIS bits for each PORTC pin. Some peripherals override the TRIS bit to make a pin an output, while other peripherals override the TRIS bit to make a pin an input. Since the TRIS bit override is in effect while the peripheral is enabled, read-modifywrite instructions (BSF, BCF, XORWF) with TRISC as the destination should be avoided. The user should refer to the corresponding peripheral section for the correct TRIS bit settings. D CK I/O pin(1) Q Q N TRIS Latch Vss Schmitt Trigger RD TRIS Peripheral OE(3) Q D EN RD PORT Peripheral Input Note 1: I/O pins have diode protection to VDD and VSS. 2: Port/Peripheral Select signal selects between port data and peripheral output. 3: Peripheral OE (Output Enable) is only activated if Peripheral Select is active. TABLE 4-5: PORTC FUNCTIONS Name Bit# Buffer Type Function RC0/T1OSO/T1CKI bit0 ST Input/output port pin or Timer1 oscillator output/Timer1 clock input. RC1/T1OSI bit1 ST Input/output port pin or Timer1 oscillator input. RC2/CCP1 bit2 ST Input/output port pin or Capture1 input/Compare1 output/ PWM1 output. RC3 bit3 ST Input/output port pin. RC4 bit4 ST Input/output port pin. RC5 bit5 ST Input/output port pin. RC6/TX/CK bit6 ST Input/output port pin or USART Asynchronous Transmit or Synchronous Clock. RC7/RX/DT bit7 ST Input/output port pin or USART Asynchronous Receive or Synchronous Data. Legend: ST = Schmitt Trigger input TABLE 4-6: Address SUMMARY OF REGISTERS ASSOCIATED WITH PORTC Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other RESETS RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 xxxx xxxx uuuu uuuu 1111 1111 1111 1111 07h PORTC 87h TRISC Legend: x = unknown, u = unchanged PORTC Data Direction Register 2000-2013 Microchip Technology Inc. DS30569C-page 37 PIC16F870/871 4.4 FIGURE 4-6: PORTD and TRISD Registers PORTD BLOCK DIAGRAM (IN I/O PORT MODE) This section is not applicable to the PIC16F870. Data Bus PORTD is an 8-bit port with Schmitt Trigger input buffers. Each pin is individually configurable as an input or output. WR Port PORTD can be configured as an 8-bit wide microprocessor port (parallel slave port) by setting control bit PSPMODE (TRISE<4>). In this mode, the input buffers are TTL. D Q I/O pin(1) CK Data Latch D WR TRIS Q Schmitt Trigger Input Buffer CK TRIS Latch RD TRIS Q D ENEN RD Port Note 1: I/O pins have protection diodes to VDD and VSS. TABLE 4-7: PORTD FUNCTIONS Name Bit# Buffer Type RD0/PSP0 bit0 ST/TTL(1) Input/output port pin or parallel slave port bit0. RD1/PSP1 bit1 ST/TTL (1) Input/output port pin or parallel slave port bit1. RD2/PSP2 bit2 ST/TTL (1) Input/output port pin or parallel slave port bit2. RD3/PSP3 bit3 ST/TTL(1) Input/output port pin or parallel slave port bit3. RD4/PSP4 bit4 ST/TTL(1) Input/output port pin or parallel slave port bit4. RD5/PSP5 bit5 ST/TTL(1) Input/output port pin or parallel slave port bit5. RD6/PSP6 bit6 ST/TTL(1) Input/output port pin or parallel slave port bit6. RD7/PSP7 bit7 ST/TTL(1) Input/output port pin or parallel slave port bit7. Legend: Note 1: ST = Schmitt Trigger input, TTL = TTL input Input buffers are Schmitt Triggers when in I/O mode and TTL buffers when in Parallel Slave Port mode. TABLE 4-8: Address Function SUMMARY OF REGISTERS ASSOCIATED WITH PORTD Name 08h PORTD 88h TRISD 89h TRISE Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other RESETS RD7 RD6 RD5 RD4 RD3 RD2 RD1 RD0 xxxx xxxx uuuu uuuu 1111 1111 1111 1111 0000 -111 0000 -111 PORTD Data Direction Register IBF OBF IBOV PSPMODE -- PORTE Data Direction Bits Legend: x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used by PORTD. DS30569C-page 38 2000-2013 Microchip Technology Inc. PIC16F870/871 4.5 PORTE and TRISE Register This section is not applicable to the PIC16F870. PORTE has three pins, RE0/RD/AN5, RE1/WR/AN6 and RE2/CS/AN7, which are individually configurable as inputs or outputs. These pins have Schmitt Trigger input buffers. I/O PORTE becomes control inputs for the microprocessor port when bit PSPMODE (TRISE<4>) is set. In this mode, the user must make sure that the TRISE<2:0> bits are set (pins are configured as digital inputs). Ensure ADCON1 is configured for digital I/O. In this mode, the input buffers are TTL. FIGURE 4-7: Data Bus WR PORT On a Power-on Reset, these pins are configured as analog inputs. 2000-2013 Microchip Technology Inc. Q I/O pin(1) CK D WR TRIS Q Schmitt Trigger input buffer CK TRIS Latch RD TRIS PORTE pins are multiplexed with analog inputs. When selected as an analog input, these pins will read as '0's. Note: D Data Latch Register 4-1 shows the TRISE register, which also controls the parallel slave port operation. TRISE controls the direction of the RE pins, even when they are being used as analog inputs. The user must make sure to keep the pins configured as inputs when using them as analog inputs. PORTE BLOCK DIAGRAM (IN I/O PORT MODE) Q D EN RD PORT Note 1: I/O pins have protection diodes to VDD and VSS. DS30569C-page 39 PIC16F870/871 REGISTER 4-1: TRISE REGISTER (ADDRESS: 89h) R-0 R-0 R/W-0 R/W-0 U-0 R/W-1 R/W-1 R/W-1 IBF OBF IBOV PSPMODE -- Bit2 Bit1 Bit0 bit 7 bit 0 bit 7 Parallel Slave Port Status/Control Bits IBF: Input Buffer Full Status bit 1 = A word has been received and is waiting to be read by the CPU 0 = No word has been received bit 6 OBF: Output Buffer Full Status bit 1 = The output buffer still holds a previously written word 0 = The output buffer has been read bit 5 IBOV: Input Buffer Overflow Detect bit (in Microprocessor mode) 1 = A write occurred when a previously input word has not been read (must be cleared in software) 0 = No overflow occurred bit 4 PSPMODE: Parallel Slave Port Mode Select bit 1 = Parallel Slave Port mode 0 = General Purpose I/O mode bit 3 Unimplemented: Read as '0' PORTE Data Direction Bits bit 2 Bit2: Direction Control bit for pin RE2/CS/AN7 1 = Input 0 = Output bit 1 Bit1: Direction Control bit for pin RE1/WR/AN6 1 = Input 0 = Output bit 0 Bit0: Direction Control bit for pin RE0/RD/AN5 1 = Input 0 = Output Legend: DS30569C-page 40 R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown 2000-2013 Microchip Technology Inc. PIC16F870/871 TABLE 4-9: Name PORTE FUNCTIONS Bit# Buffer Type Function RE0/RD/AN5 bit0 ST/TTL(1) Input/output port pin or read control input in Parallel Slave Port mode or analog input: RD 1 = Not a read operation 0 = Read operation. Reads PORTD register (if chip selected.) RE1/WR/AN6 bit1 ST/TTL(1) Input/output port pin or write control input in Parallel Slave Port mode or analog input: WR 1 = Not a write operation 0 = Write operation. Writes PORTD register (if chip selected). RE2/CS/AN7 bit2 ST/TTL(1) Input/output port pin or chip select control input in Parallel Slave Port mode or analog input: CS 1 = Device is not selected 0 = Device is selected Legend: Note 1: ST = Schmitt Trigger input, TTL = TTL input Input buffers are Schmitt Triggers when in I/O mode and TTL buffers when in Parallel Slave Port mode. TABLE 4-10: Addr Name SUMMARY OF REGISTERS ASSOCIATED WITH PORTE Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 09h PORTE -- -- -- -- -- 89h TRISE IBF OBF IBOV PSPMODE -- 9Fh ADCON1 ADFM -- -- -- PCFG3 Legend: Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other RESETS RE2 RE1 RE0 ---- -xxx ---- -uuu 0000 -111 0000 -111 --0- 0000 --0- 0000 PORTE Data Direction Bits PCFG2 PCFG1 PCFG0 x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used by PORTE. 2000-2013 Microchip Technology Inc. DS30569C-page 41 PIC16F870/871 4.6 Parallel Slave Port FIGURE 4-8: PORTD AND PORTE BLOCK DIAGRAM (PARALLEL SLAVE PORT) The Parallel Slave Port is not implemented on the PIC16F870. PORTD operates as an 8-bit wide Parallel Slave Port or microprocessor port when control bit PSPMODE (TRISE<4>) is set. In Slave mode, it is asynchronously readable and writable by the external world through RD control input pin RE0/RD and WR control input pin RE1/WR. It can directly interface to an 8-bit microprocessor data bus. The external microprocessor can read or write the PORTD latch as an 8-bit latch. Setting bit PSPMODE enables port pin RE0/RD to be the RD input, RE1/WR to be the WR input and RE2/CS to be the CS (chip select) input. For this functionality, the corresponding data direction bits of the TRISE register (TRISE<2:0>) must be configured as inputs (set). The A/D port configuration bits PCFG3:PCFG0 (ADCON1<3:0>) must be set to configure pins RE2:RE0 as digital I/O. There are actually two 8-bit latches. One for data output and one for data input. The user writes 8-bit data to the PORTD data latch and reads data from the port pin latch (note that they have the same address). In this mode, the TRISD register is ignored, since the microprocessor is controlling the direction of data flow. A write to the PSP occurs when both the CS and WR lines are first detected low. When either the CS or WR lines become high (level triggered), the Input Buffer Full (IBF) status flag bit (TRISE<7>) is set on the Q4 clock cycle, following the next Q2 cycle, to signal the write is complete (Figure 4-9). The interrupt flag bit, PSPIF (PIR1<7>), is also set on the same Q4 clock cycle. IBF can only be cleared by reading the PORTD input latch. The Input Buffer Overflow (IBOV) status flag bit (TRISE<5>) is set if a second write to the PSP is attempted when the previous byte has not been read out of the buffer. Data Bus D WR Port Q RDx pin CK TTL Q RD Port D ENEN One bit of PORTD Set Interrupt Flag PSPIF (PIR1<7>) Read TTL RD Chip Select TTL CS Write TTL WR Note: I/O pin has protection diodes to VDD and VSS. A read from the PSP occurs when both the CS and RD lines are first detected low. The Output Buffer Full (OBF) status flag bit (TRISE<6>) is cleared immediately (Figure 4-10), indicating that the PORTD latch is waiting to be read by the external bus. When either the CS or RD pin becomes high (level triggered), the interrupt flag bit PSPIF is set on the Q4 clock cycle, following the next Q2 cycle, indicating that the read is complete. OBF remains low until data is written to PORTD by the user firmware. When not in PSP mode, the IBF and OBF bits are held clear. However, if flag bit IBOV was previously set, it must be cleared in firmware. An interrupt is generated and latched into flag bit PSPIF when a read or write operation is completed. PSPIF must be cleared by the user in firmware and the interrupt can be disabled by clearing the interrupt enable bit PSPIE (PIE1<7>). DS30569C-page 42 2000-2013 Microchip Technology Inc. PIC16F870/871 FIGURE 4-9: PARALLEL SLAVE PORT WRITE WAVEFORMS Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q4 Q1 Q2 Q3 Q4 CS WR RD PORTD<7:0> IBF OBF PSPIF FIGURE 4-10: PARALLEL SLAVE PORT READ WAVEFORMS Q1 Q2 Q3 Q4 Q1 Q2 Q3 CS WR RD PORTD<7:0> IBF OBF PSPIF TABLE 4-11: Address REGISTERS ASSOCIATED WITH PARALLEL SLAVE PORT Name 08h PORTD 09h PORTE 89h TRISE 0Ch PIR1 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 RE1 RE0 Port Data Latch when written: Port pins when read RE2 Value on: POR, BOR Value on all other RESETS xxxx xxxx uuuu uuuu ---- -xxx ---- -uuu -- -- -- -- -- IBF OBF IBOV PSPMODE -- PORTE Data Direction bits 0000 -111 0000 -111 PSPIF ADIF RCIF TXIF -- CCP1IF TMR2IF TMR1IF 0000 0000 0000 0000 RCIE TXIE -- CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000 -- -- PCFG3 PCFG2 --0- 0000 --0- 0000 8Ch PIE1 PSPIE ADIE 9Fh ADCON1 ADFM Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Parallel Slave Port. -- 2000-2013 Microchip Technology Inc. PCFG1 PCFG0 DS30569C-page 43 PIC16F870/871 NOTES: DS30569C-page 44 2000-2013 Microchip Technology Inc. PIC16F870/871 5.0 TIMER0 MODULE Counter mode is selected by setting bit T0CS (OPTION_REG<5>). In Counter mode, Timer0 will increment either on every rising, or falling edge of pin RA4/T0CKI. The incrementing edge is determined by the Timer0 Source Edge Select bit, T0SE (OPTION_REG<4>). Clearing bit T0SE selects the rising edge. Restrictions on the external clock input are discussed in detail in Section 5.2. The Timer0 module timer/counter has the following features: * * * * * * 8-bit timer/counter Readable and writable 8-bit software programmable prescaler Internal or external clock select Interrupt on overflow from FFh to 00h Edge select for external clock The prescaler is mutually exclusively shared between the Timer0 module and the Watchdog Timer. The prescaler is not readable or writable. Section 5.3 details the operation of the prescaler. Figure 5-1 is a block diagram of the Timer0 module and the prescaler shared with the WDT. 5.1 Additional information on the Timer0 module is available in the PIC(R) Mid-Range MCU Family Reference Manual (DS33023). The TMR0 interrupt is generated when the TMR0 register overflows from FFh to 00h. This overflow sets bit T0IF (INTCON<2>). The interrupt can be masked by clearing bit T0IE (INTCON<5>). Bit T0IF must be cleared in software by the Timer0 module Interrupt Service Routine before re-enabling this interrupt. The TMR0 interrupt cannot awaken the processor from SLEEP, since the timer is shut-off during SLEEP. Timer mode is selected by clearing bit T0CS (OPTION_REG<5>). In Timer mode, the Timer0 module will increment every instruction cycle (without prescaler). If the TMR0 register is written, the increment is inhibited for the following two instruction cycles. The user can work around this by writing an adjusted value to the TMR0 register. FIGURE 5-1: Timer0 Interrupt BLOCK DIAGRAM OF THE TIMER0/WDT PRESCALER Data Bus CLKO (= FOSC/4) 0 RA4/T0CKI pin 8 M U X 1 M U X 0 1 SYNC 2 Cycles TMR0 Reg T0SE T0CS Set Flag Bit T0IF on Overflow PSA PRESCALER 0 Watchdog Timer 1 M U X 8-bit Prescaler 8 8 - to - 1MUX PS2:PS0 PSA WDT Enable bit 1 0 MUX PSA WDT Time-out Note: T0CS, T0SE, PSA, PS2:PS0 are (OPTION_REG<5:0>). 2000-2013 Microchip Technology Inc. DS30569C-page 45 PIC16F870/871 5.2 Using Timer0 with an External Clock 5.3 When no prescaler is used, the external clock input is the same as the prescaler output. The synchronization of T0CKI with the internal phase clocks is accomplished by sampling the prescaler output on the Q2 and Q4 cycles of the internal phase clocks. Therefore, it is necessary for T0CKI to be high for at least 2 TOSC (and a small RC delay of 20 ns) and low for at least 2 TOSC (and a small RC delay of 20 ns). Refer to the electrical specification of the desired device. There is only one prescaler available, which is mutually exclusively shared between the Timer0 module and the Watchdog Timer. A prescaler assignment for the Timer0 module means that there is no prescaler for the Watchdog Timer, and vice-versa. This prescaler is not readable or writable (see Figure 5-1). The PSA and PS2:PS0 bits (OPTION_REG<3:0>) determine the prescaler assignment and prescale ratio. When assigned to the Timer0 module, all instructions writing to the TMR0 register (e.g., CLRF1, MOVWF1, BSF1,x....etc.) will clear the prescaler. When assigned to WDT, a CLRWDT instruction will clear the prescaler along with the Watchdog Timer. The prescaler is not readable or writable. Note: REGISTER 5-1: Prescaler Writing to TMR0 when the prescaler is assigned to Timer0, will clear the prescaler count, but will not change the prescaler assignment. OPTION_REG REGISTER R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 RBPU INTEDG T0CS T0SE PSA PS2 PS1 PS0 bit 7 bit 0 bit 7 RBPU bit 6 INTEDG bit 5 T0CS: TMR0 Clock Source Select bit 1 = Transition on T0CKI pin 0 = Internal instruction cycle clock (CLKO) bit 4 T0SE: TMR0 Source Edge Select bit 1 = Increment on high-to-low transition on T0CKI pin 0 = Increment on low-to-high transition on T0CKI pin bit 3 PSA: Prescaler Assignment bit 1 = Prescaler is assigned to the WDT 0 = Prescaler is assigned to the Timer0 module bit 2-0 PS2:PS0: Prescaler Rate Select bits Bit Value TMR0 Rate WDT Rate 000 001 010 011 100 101 110 111 1:2 1:4 1:8 1 : 16 1 : 32 1 : 64 1 : 128 1 : 256 1:1 1:2 1:4 1:8 1 : 16 1 : 32 1 : 64 1 : 128 Legend: Note: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown To avoid an unintended device RESET, the instruction sequence shown in the PIC(R) Mid-Range MCU Family Reference Manual (DS33023) must be executed when changing the prescaler assignment from Timer0 to the WDT. This sequence must be followed even if the WDT is disabled. DS30569C-page 46 2000-2013 Microchip Technology Inc. PIC16F870/871 TABLE 5-1: Address 01h,101h REGISTERS ASSOCIATED WITH TIMER0 Name TMR0 0Bh,8Bh, INTCON 10Bh,18Bh 81h,181h Legend: Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Timer0 Module's Register GIE PEIE T0IE Value on: POR, BOR Value on all other RESETS xxxx xxxx uuuu uuuu INTE RBIE OPTION_REG RBPU INTEDG T0CS T0SE PSA T0IF INTF RBIF 0000 000x 0000 000u PS2 PS1 PS0 1111 1111 1111 1111 x = unknown, u = unchanged, - = unimplemented locations read as '0'. Shaded cells are not used by Timer0. 2000-2013 Microchip Technology Inc. DS30569C-page 47 PIC16F870/871 NOTES: DS30569C-page 48 2000-2013 Microchip Technology Inc. PIC16F870/871 6.0 TIMER1 MODULE The Timer1 module is a 16-bit timer/counter consisting of two 8-bit registers (TMR1H and TMR1L), which are readable and writable. The TMR1 register pair (TMR1H:TMR1L) increments from 0000h to FFFFh and rolls over to 0000h. The TMR1 interrupt, if enabled, is generated on overflow, which is latched in interrupt flag bit, TMR1IF (PIR1<0>). This interrupt can be enabled/disabled by setting/clearing TMR1 interrupt enable bit, TMR1IE (PIE1<0>). Timer1 can operate in one of two modes: * As a timer * As a counter The Operating mode is determined by the clock select bit, TMR1CS (T1CON<1>). REGISTER 6-1: In Timer mode, Timer1 increments every instruction cycle. In Counter mode, it increments on every rising edge of the external clock input. Timer1 can be enabled/disabled by setting/clearing control bit, TMR1ON (T1CON<0>). Timer1 also has an internal "RESET input". This RESET can be generated by either of the two CCP modules (Section 8.0). Register 6-1 shows the Timer1 control register. When the Timer1 oscillator is enabled (T1OSCEN is set), the RC1/T1OSI and RC0/T1OSO/T1CKI pins become inputs. That is, the TRISC<1:0> value is ignored, and these pins read as `0'. Additional information on timer modules is available in the PIC(R) Mid-Range MCU Family Reference Manual (DS33023). T1CON: TIMER1 CONTROL REGISTER (ADDRESS: 10h) U-0 U-0 -- -- R/W-0 R/W-0 T1CKPS1 T1CKPS0 R/W-0 T1OSCEN R/W-0 R/W-0 bit 7 bit 0 bit 7-6 Unimplemented: Read as '0' bit 5-4 T1CKPS1:T1CKPS0: Timer1 Input Clock Prescale Select bits 11 = 1:8 Prescale value 10 = 1:4 Prescale value 01 = 1:2 Prescale value 00 = 1:1 Prescale value bit 3 T1OSCEN: Timer1 Oscillator Enable Control bit 1 = Oscillator is enabled 0 = Oscillator is shut-off (the oscillator inverter is turned off to eliminate power drain) bit 2 T1SYNC: Timer1 External Clock Input Synchronization Control bit When TMR1CS = 1: 1 = Do not synchronize external clock input 0 = Synchronize external clock input When TMR1CS = 0: This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0. bit 1 TMR1CS: Timer1 Clock Source Select bit 1 = External clock from pin RC0/T1OSO/T1CKI (on the rising edge) 0 = Internal clock (FOSC/4) bit 0 R/W-0 T1SYNC TMR1CS TMR1ON TMR1ON: Timer1 On bit 1 = Enables Timer1 0 = Stops Timer1 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared 2000-2013 Microchip Technology Inc. x = Bit is unknown DS30569C-page 49 PIC16F870/871 6.1 Timer1 Operation in Timer Mode Timer mode is selected by clearing the TMR1CS (T1CON<1>) bit. In this mode, the input clock to the timer is FOSC/4. The synchronize control bit, T1SYNC (T1CON<2>), has no effect, since the internal clock is always in sync. FIGURE 6-1: 6.2 Timer1 Counter Operation Timer1 may operate in either a Synchronous, or an Asynchronous mode, depending on the setting of the TMR1CS bit. When Timer1 is being incremented via an external source, increments occur on a rising edge. After Timer1 is enabled in Counter mode, the module must first have a falling edge before the counter begins to increment. TIMER1 INCREMENTING EDGE T1CKI (Default High) T1CKI (Default Low) Note: Arrows indicate counter increments. 6.3 Timer1 Operation in Synchronized Counter Mode Counter mode is selected by setting bit TMR1CS. In this mode, the timer increments on every rising edge of clock input on pin RC1/T1OSI, when bit T1OSCEN is set, or on pin RC0/T1OSO/T1CKI, when bit T1OSCEN is cleared. FIGURE 6-2: If T1SYNC is cleared, then the external clock input is synchronized with internal phase clocks. The synchronization is done after the prescaler stage. The prescaler stage is an asynchronous ripple counter. In this configuration, during SLEEP mode, Timer1 will not increment even if the external clock is present, since the synchronization circuit is shut-off. The prescaler, however, will continue to increment. TIMER1 BLOCK DIAGRAM Set Flag bit TMR1IF on Overflow 0 TMR1 TMR1H Synchronized Clock Input TMR1L 1 TMR1ON On/Off T1SYNC T1OSC RC0/T1OSO/T1CKI RC1/T1OSI 1 T1OSCEN FOSC/4 Enable Internal Oscillator(1) Clock Prescaler 1, 2, 4, 8 Synchronize det 0 2 T1CKPS1:T1CKPS0 Q Clock TMR1CS Note 1: When the T1OSCEN bit is cleared, the inverter is turned off. This eliminates power drain. DS30569C-page 50 2000-2013 Microchip Technology Inc. PIC16F870/871 6.4 Timer1 Operation in Asynchronous Counter Mode TABLE 6-1: CAPACITOR SELECTION FOR THE TIMER1 OSCILLATOR If control bit T1SYNC (T1CON<2>) is set, the external clock input is not synchronized. The timer continues to increment asynchronous to the internal phase clocks. The timer will continue to run during SLEEP and can generate an interrupt-on-overflow, which will wake-up the processor. However, special precautions in software are needed to read/write the timer (Section 6.4.1). Osc Type In Asynchronous Counter mode, Timer1 cannot be used as a time base for capture or compare operations. 32.768 kHz Epson C-001R32.768K-A 20 PPM 100 kHz Epson C-2 100.00 KC-P 20 PPM 200 kHz STD XTL 200.000 kHz 20 PPM 6.4.1 READING AND WRITING TIMER1 IN ASYNCHRONOUS COUNTER MODE Reading TMR1H or TMR1L while the timer is running from an external asynchronous clock, will ensure a valid read (taken care of in hardware). However, the user should keep in mind that reading the 16-bit timer in two 8-bit values itself, poses certain problems, since the timer may overflow between the reads. For writes, it is recommended that the user simply stop the timer and write the desired values. A write contention may occur by writing to the timer registers, while the register is incrementing. This may produce an unpredictable value in the timer register. Reading the 16-bit value requires some care. Examples 12-2 and 12-3 in the PIC(R) Mid-Range MCU Family Reference Manual (DS33023) show how to read and write Timer1 when it is running in Asynchronous mode. 6.5 Timer1 Oscillator A crystal oscillator circuit is built-in between pins T1OSI (input) and T1OSO (amplifier output). It is enabled by setting control bit, T1OSCEN (T1CON<3>). The oscillator is a low power oscillator, rated up to 200 kHz. It will continue to run during SLEEP. It is primarily intended for use with a 32 kHz crystal. Table 6-1 shows the capacitor selection for the Timer1 oscillator. LP Freq. C1 C2 32 kHz 33 pF 33 pF 100 kHz 15 pF 15 pF 200 kHz 15 pF 15 pF These values are for design guidance only. Crystals Tested: Note 1: 2: 6.6 Higher capacitance increases the stability of oscillator, but also increases the start-up time. Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components. Resetting Timer1 Using a CCP Trigger Output If the CCP1 module is configured in Compare mode to generate a "special event trigger" (CCP1M3:CCP1M0 = 1011), this signal will reset Timer1. Note: The special event triggers from the CCP1 module will not set interrupt flag bit TMR1IF (PIR1<0>). Timer1 must be configured for either Timer or Synchronized Counter mode to take advantage of this feature. If Timer1 is running in Asynchronous Counter mode, this RESET operation may not work. In the event that a write to Timer1 coincides with a special event trigger from CCP1, the write will take precedence. In this mode of operation, the CCPRH:CCPRL register pair effectively becomes the period register for Timer1. The Timer1 oscillator is identical to the LP oscillator. The user must provide a software time delay to ensure proper oscillator start-up. 2000-2013 Microchip Technology Inc. DS30569C-page 51 PIC16F870/871 6.7 Resetting of Timer1 Register Pair (TMR1H, TMR1L) 6.8 Timer1 Prescaler The prescaler counter is cleared on writes to the TMR1H or TMR1L registers. TMR1H and TMR1L registers are not reset to 00h on a POR, or any other RESET, except by the CCP1 special event trigger. T1CON register is reset to 00h on a Power-on Reset, or a Brown-out Reset, which shuts off the timer and leaves a 1:1 prescale. In all other RESETS, the register is unaffected. TABLE 6-2: REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER Value on all other RESETS Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR GIE PEIE T0IE INTE RBIE T0IF INTF RBIF 0000 000x 0000 000u PIR1 PSPIF(1) ADIF RCIF TXIF -- CCP1IF TMR2IF 8Ch PIE1 PSPIE(1) ADIE RCIE TXIE -- CCP1IE TMR2IE TMR1IE 0000 -000 0000 -000 0Eh TMR1L Holding Register for the Least Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu 0Fh TMR1H Holding Register for the Most Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu 10h T1CON Legend: Note 1: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Timer1 module. Bits PSPIE and PSPIF are reserved on the PIC16F870; always maintain these bits clear. Address Name 0Bh,8Bh, INTCON 10Bh, 18Bh 0Ch DS30569C-page 52 -- -- TMR1IF 0000 -000 0000 -000 T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON --00 0000 --uu uuuu 2000-2013 Microchip Technology Inc. PIC16F870/871 7.0 TIMER2 MODULE Register 7-1 shows the Timer2 control register. Timer2 is an 8-bit timer with a prescaler and a postscaler. It can be used as the PWM time base for the PWM mode of the CCP module(s). The TMR2 register is readable and writable, and is cleared on any device RESET. Additional information on timer modules is available in the PIC(R) Mid-Range MCU Family Reference Manual (DS33023). FIGURE 7-1: The input clock (FOSC/4) has a prescale option of 1:1, 1:4, or 1:16, selected by control bits T2CKPS1:T2CKPS0 (T2CON<1:0>). Sets Flag bit TMR2IF TIMER2 BLOCK DIAGRAM TMR2 Output(1) RESET The Timer2 module has an 8-bit period register, PR2. Timer2 increments from 00h until it matches PR2 and then resets to 00h on the next increment cycle. PR2 is a readable and writable register. The PR2 register is initialized to FFh upon RESET. Postscaler 1:1 to 1:16 EQ 4 The match output of TMR2 goes through a 4-bit postscaler (which gives a 1:1 to 1:16 scaling inclusive) to generate a TMR2 interrupt (latched in flag bit TMR2IF (PIR1<1>)). TMR2 Reg Prescaler 1:1, 1:4, 1:16 2 Comparator PR2 Reg FOSC/4 T2CKPS1: T2CKPS0 T2OUTPS3: T2OUTPS0 Note 1: TMR2 register output can be software selected by the SSP module as a baud clock. Timer2 can be shut-off by clearing control bit, TMR2ON (T2CON<2>), to minimize power consumption. REGISTER 7-1: T2CON: TIMER2 CONTROL REGISTER (ADDRESS 12h) U-0 -- R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 bit 7 bit 0 bit 7 Unimplemented: Read as '0' bit 6-3 TOUTPS3:TOUTPS0: Timer2 Output Postscale Select bits 0000 = 1:1 Postscale 0001 = 1:2 Postscale 0010 = 1:3 Postscale * * * 1111 = 1:16 Postscale bit 2 TMR2ON: Timer2 On bit 1 = Timer2 is on 0 = Timer2 is off bit 1-0 T2CKPS1:T2CKPS0: Timer2 Clock Prescale Select bits 00 = Prescaler is 1 01 = Prescaler is 4 1x = Prescaler is 16 Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared 2000-2013 Microchip Technology Inc. x = Bit is unknown DS30569C-page 53 PIC16F870/871 7.1 Timer2 Prescaler and Postscaler The prescaler and postscaler counters are cleared when any of the following occurs: * a write to the TMR2 register * a write to the T2CON register * any device RESET (POR, MCLR Reset, WDT Reset, or BOR) 7.2 Output of TMR2 The output of TMR2 (before the postscaler) is fed to the SSP module, which optionally uses it to generate shift clock. TMR2 is not cleared when T2CON is written. TABLE 7-1: Address REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER Name 0Bh,8Bh, INTCON 10Bh,18Bh Value on all other RESETS Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR GIE PEIE T0IE INTE RBIE T0IF INTF RBIF 0000 000x 0000 000u 0Ch PIR1 PSPIF(1) ADIF RCIF TXIF -- CCP1IF TMR2IF TMR1IF 0000 -000 0000 -000 8Ch PIE1 PSPIE(1) ADIE RCIE TXIE -- CCP1IE TMR2IE TMR1IE 0000 -000 0000 -000 11h TMR2 Timer2 Module's Register 12h T2CON 92h PR2 Legend: Note 1: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Timer2 module. Bits PSPIE and PSPIF are reserved on the PIC16F870; always maintain these bits clear. DS30569C-page 54 -- 0000 0000 0000 0000 TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000 Timer2 Period Register 1111 1111 1111 1111 2000-2013 Microchip Technology Inc. PIC16F870/871 8.0 CAPTURE/COMPARE/PWM MODULES Each Capture/Compare/PWM (CCP) module contains a 16-bit register which can operate as a: Additional information on CCP modules is available in the PIC(R) Mid-Range MCU Family Reference Manual (DS33023) and in application note AN594, "Using the CCP Modules" (DS00594). TABLE 8-1: * 16-bit Capture register * 16-bit Compare register * PWM Master/Slave Duty Cycle register Table 8-1 shows the resources and interactions of the CCP module. In the following sections, the operation of a CCP module is described. 8.1 CCP MODE - TIMER RESOURCES REQUIRED CCP Mode Timer Resource Capture Compare PWM Timer1 Timer1 Timer2 CCP1 Module Capture/Compare/PWM Register1 (CCPR1) is comprised of two 8-bit registers: CCPR1L (low byte) and CCPR1H (high byte). The CCP1CON register controls the operation of CCP1. The special event trigger is generated by a compare match and will reset Timer1 and start an A/D conversion (if the A/D module is enabled). REGISTER 8-1: CCP1CON REGISTER REGISTER (ADDRESS: 17h/1Dh) U-0 U-0 R/W-0 R/W-0 R/W-0 -- -- CCP1X CCP1Y CCP1M3 R/W-0 R/W-0 CCP1M2 CCP1M1 R/W-0 CCP1M0 bit 7 bit 0 bit 7-6 Unimplemented: Read as '0' bit 5-4 CCP1X:CCP1Y: PWM Least Significant bits Capture mode: Unused Compare mode: Unused PWM mode: These bits are the two LSbs of the PWM duty cycle. The eight MSbs are found in CCPR1L. bit 3-0 CCP1M3:CCP1M0: CCP1 Mode Select bits 0000 = Capture/Compare/PWM disabled (resets CCP1 module) 0100 = Capture mode, every falling edge 0101 = Capture mode, every rising edge 0110 = Capture mode, every 4th rising edge 0111 = Capture mode, every 16th rising edge 1000 = Compare mode, set output on match (CCP1IF bit is set) 1001 = Compare mode, clear output on match (CCP1IF bit is set) 1010 = Compare mode, generate software interrupt on match (CCP1IF bit is set, CCP1 pin is unaffected) 1011 = Compare mode, trigger special event (CCP1IF bit is set, CCP1 pin is unaffected); CCP1resets TMR1, and starts an A/D conversion (if A/D module is enabled) 11xx = PWM mode Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared 2000-2013 Microchip Technology Inc. x = Bit is unknown DS30569C-page 55 PIC16F870/871 8.2 8.2.2 Capture Mode TIMER1 MODE SELECTION In Capture mode, CCPR1H:CCPR1L captures the 16-bit value of the TMR1 register when an event occurs on pin RC2/CCP1. An event is defined as one of the following: Timer1 must be running in Timer mode, or Synchronized Counter mode, for the CCP module to use the capture feature. In Asynchronous Counter mode, the capture operation may not work. * * * * 8.2.3 Every falling edge Every rising edge Every 4th rising edge Every 16th rising edge The type of event is configured by control bits CCP1M3:CCP1M0 (CCP1CON<3:0>). When a capture is made, the interrupt request flag bit CCP1IF (PIR1<2>) is set. The interrupt flag must be cleared in software. If another capture occurs before the value in register CCPR1 is read, the old captured value is overwritten by the new value. 8.2.1 CCP PIN CONFIGURATION In Capture mode, the RC2/CCP1 pin should be configured as an input by setting the TRISC<2> bit. Note: If the RC2/CCP1 pin is configured as an output, a write to the port can cause a capture condition. FIGURE 8-1: RC2/CCP1 pin CAPTURE MODE OPERATION BLOCK DIAGRAM Prescaler 1, 4, 16 Set Flag bit CCP1IF (PIR1<2>) CCPR1H When the Capture mode is changed, a false capture interrupt may be generated. The user should keep bit CCP1IE (PIE1<2>) clear to avoid false interrupts and should clear the flag bit, CCP1IF, following any such change in Operating mode. 8.2.4 Switching from one capture prescaler to another may generate an interrupt. Also, the prescaler counter will not be cleared, therefore, the first capture may be from a non-zero prescaler. Example 8-1 shows the recommended method for switching between capture prescalers. This example also clears the prescaler counter and will not generate the "false" interrupt. EXAMPLE 8-1: CLRF MOVLW CCPR1L Capture Enable TMR1H CCP PRESCALER There are four prescaler settings, specified by bits CCP1M3:CCP1M0. Whenever the CCP module is turned off, or the CCP module is not in Capture mode, the prescaler counter is cleared. Any RESET will clear the prescaler counter. MOVWF and Edge Detect SOFTWARE INTERRUPT CHANGING BETWEEN CAPTURE PRESCALERS CCP1CON ; Turn CCP module off NEW_CAPT_PS ; Load the W reg with ; the new prescaler ; move value and CCP ON CCP1CON ; Load CCP1CON with this ; value TMR1L CCP1CON<3:0> Qs DS30569C-page 56 2000-2013 Microchip Technology Inc. PIC16F870/871 8.3 8.3.2 Compare Mode In Compare mode, the 16-bit CCPR1 register value is constantly compared against the TMR1 register pair value. When a match occurs, the RC2/CCP1 pin is: * Driven high * Driven low * Remains unchanged FIGURE 8-2: COMPARE MODE OPERATION BLOCK DIAGRAM Special event trigger will: reset Timer1, but not set interrupt flag bit TMR1IF (PIR1<0>), and set bit GO/DONE (ADCON0<2>). Special Event Trigger RC2/CCP1 pin CCPR1H CCPR1L S R TRISC<2> Output Enable 8.3.1 Output Logic Match CCP1CON<3:0> Mode Select SOFTWARE INTERRUPT MODE When Generate Software Interrupt mode is chosen, the CCP1 pin is not affected. The CCPIF bit is set, causing a CCP interrupt (if enabled). 8.3.4 SPECIAL EVENT TRIGGER In this mode, an internal hardware trigger is generated, which may be used to initiate an action. The special event trigger output of CCP1 resets the TMR1 register pair, and starts an A/D conversion (if A/D module is enabled). This allows the CCPR1 register to effectively be a 16-bit programmable period register for Timer1. Note: Set Flag bit CCP1IF (PIR1<2>) Q Timer1 must be running in Timer mode, or Synchronized Counter mode, if the CCP module is using the compare feature. In Asynchronous Counter mode, the compare operation may not work. 8.3.3 The action on the pin is based on the value of control bits, CCP1M3:CCP1M0 (CCP1CON<3:0>). At the same time, interrupt flag bit CCP1IF is set. TIMER1 MODE SELECTION The special event trigger from the CCP1 module will not set interrupt flag bit TMR1IF (PIR1<0>). Comparator TMR1H TMR1L CCP PIN CONFIGURATION The user must configure the RC2/CCP1 pin as an output by clearing the TRISC<2> bit. Note: Clearing the CCP1CON register will force the RC2/CCP1 compare output latch to the default low level. This is not the PORTC I/O data latch. 2000-2013 Microchip Technology Inc. DS30569C-page 57 PIC16F870/871 8.4 8.4.1 PWM Mode (PWM) In Pulse Width Modulation mode, the CCP1 pin produces up to a 10-bit resolution PWM output. Since the CCP1 pin is multiplexed with the PORTC data latch, the TRISC<2> bit must be cleared to make the CCP1 pin an output. Note: Clearing the CCP1CON register will force the CCP1 PWM output latch to the default low level. This is not the PORTC I/O data latch. Figure 8-3 shows a simplified block diagram of the CCP module in PWM mode. For a step-by-step procedure on how to set up the CCP module for PWM operation, see Section 8.4.3. FIGURE 8-3: SIMPLIFIED PWM BLOCK DIAGRAM Duty Cycle Registers The PWM period is specified by writing to the PR2 register. The PWM period can be calculated using the following formula: PWM period = [(PR2) + 1] * 4 * TOSC * (TMR2 prescale value) PWM frequency is defined as 1 / [PWM period]. When TMR2 is equal to PR2, the following three events occur on the next increment cycle: * TMR2 is cleared * The CCP1 pin is set (exception: if PWM duty cycle = 0%, the CCP1 pin will not be set) * The PWM duty cycle is latched from CCPR1L into CCPR1H Note: CCP1CON<5:4> CCPR1L 8.4.2 CCPR1H (Slave) RC2/CCP1 R Comparator TMR2 Q (Note 1) S TRISC<2> Comparator Clear Timer, CCP1 pin and latch D.C. PR2 Note 1: The 8-bit timer is concatenated with 2-bit internal Q clock, or 2 bits of the prescaler, to create 10-bit time base. A PWM output (Figure 8-4) has a time base (period) and a time that the output stays high (duty cycle). The frequency of the PWM is the inverse of the period (1/period). FIGURE 8-4: PWM OUTPUT Period PWM PERIOD The Timer2 postscaler (see Section 7.1) is not used in the determination of the PWM frequency. The postscaler could be used to have a servo update rate at a different frequency than the PWM output. PWM DUTY CYCLE The PWM duty cycle is specified by writing to the CCPR1L register and to the CCP1CON<5:4> bits. Up to 10-bit resolution is available. The CCPR1L contains the eight MSbs and the CCP1CON<5:4> contains the two LSbs. This 10-bit value is represented by CCPR1L:CCP1CON<5:4>. The following equation is used to calculate the PWM duty cycle in time: PWM duty cycle = (CCPR1L:CCP1CON<5:4>) * TOSC * (TMR2 prescale value) CCPR1L and CCP1CON<5:4> can be written to at any time, but the duty cycle value is not latched into CCPR1H until after a match between PR2 and TMR2 occurs (i.e., the period is complete). In PWM mode, CCPR1H is a read-only register. The CCPR1H register and a 2-bit internal latch are used to double buffer the PWM duty cycle. This double buffering is essential for glitch-free PWM operation. When the CCPR1H and 2-bit latch match TMR2, concatenated with an internal 2-bit Q clock, or 2 bits of the TMR2 prescaler, the CCP1 pin is cleared. The maximum PWM resolution (bits) for a given PWM frequency is given by the formula: Resolution Duty Cycle TMR2 = PR2 TMR2 = Duty Cycle Note: = ( FOSC log FPWM log(2) ) bits If the PWM duty cycle value is longer than the PWM period, the CCP1 pin will not be cleared. TMR2 = PR2 DS30569C-page 58 2000-2013 Microchip Technology Inc. PIC16F870/871 8.4.3 SETUP FOR PWM OPERATION The following steps should be taken when configuring the CCP module for PWM operation: 1. 2. 3. 4. 5. Set the PWM period by writing to the PR2 register. Set the PWM duty cycle by writing to the CCPR1L register and CCP1CON<5:4> bits. Make the CCP1 pin an output by clearing the TRISC<2> bit. Set the TMR2 prescale value and enable Timer2 by writing to T2CON. Configure the CCP1 module for PWM operation. TABLE 8-2: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 20 MHz PWM Frequency 1.22 kHz Timer Prescaler (1, 4, 16) PR2 Value Maximum Resolution (bits) TABLE 8-3: 4.88 kHz 19.53 kHz 78.12kHz 156.3 kHz 208.3 kHz 16 4 1 1 1 1 0xFFh 0xFFh 0xFFh 0x3Fh 0x1Fh 0x17h 10 10 10 8 7 6.5 REGISTERS ASSOCIATED WITH CAPTURE, COMPARE, AND TIMER1 Value on all other RESETS Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR 0Bh,8Bh, INTCON 10Bh, 18Bh GIE PEIE T0IE INTE RBIE T0IF INTF RBIF 0000 000x 0000 000u TMR2IF Address 0Ch PIR1 PSPIF(1) ADIF RCIF TXIF -- CCP1IF 8Ch PIE1 PSPIE(1) ADIE RCIE TXIE -- CCP1IE TMR2IE TMR1IE 0000 -000 0000 -000 87h TRISC PORTC Data Direction Register 1111 1111 1111 1111 0Eh TMR1L Holding Register for the Least Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu 0Fh TMR1H Holding Register for the Most Significant Byte of the 16-bit TMR1 Register xxxx xxxx uuuu uuuu 10h T1CON 15h CCPR1L Capture/Compare/PWM Register1 (LSB) 16h CCPR1H Capture/Compare/PWM Register1 (MSB) 17h CCP1CON Legend: Note 1: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by Capture and Timer1. The PSP is not implemented on the PIC16F870; always maintain these bits clear. -- -- -- -- 2000-2013 Microchip Technology Inc. TMR1IF 0000 -000 0000 -000 T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON --00 0000 --uu uuuu CCP1X CCP1Y xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu CCP1M3 CCP1M2 CCP1M1 CCP1M0 --00 0000 --00 0000 DS30569C-page 59 PIC16F870/871 TABLE 8-4: REGISTERS ASSOCIATED WITH PWM AND TIMER2 Value on all other RESETS Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR 0Bh,8Bh, INTCON 10Bh, 18Bh GIE PEIE T0IE INTE RBIE T0IF INTF RBIF 0000 000x 0000 000u Address 0Ch PIR1 PSPIF(1) ADIF RCIF TXIF -- CCP1IF TMR2IF TMR1IF 0000 -000 0000 -000 8Ch PIE1 PSPIE(1) ADIE RCIE TXIE -- CCP1IE TMR2IE TMR1IE 0000 -000 0000 -000 87h TRISC PORTC Data Direction Register 1111 1111 1111 1111 11h TMR2 Timer2 Module's Register 0000 0000 0000 0000 92h PR2 Timer2 Module's Period Register 1111 1111 1111 1111 12h T2CON 15h CCPR1L Capture/Compare/PWM Register1 (LSB) xxxx xxxx uuuu uuuu 16h CCPR1H Capture/Compare/PWM Register1 (MSB) xxxx xxxx uuuu uuuu -- -- TOUTPS3 TOUTPS2 TOUTPS1 TOUTPS0 TMR2ON T2CKPS1 T2CKPS0 -000 0000 -000 0000 -- CCP1X CCP1Y CCP1M3 CCP1M2 CCP1M1 CCP1M0 --00 0000 --00 0000 17h CCP1CON Legend: Note 1: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PWM and Timer2. Bits PSPIE and PSPIF are reserved on the PIC16F870; always maintain these bits clear. DS30569C-page 60 2000-2013 Microchip Technology Inc. PIC16F870/871 9.0 ADDRESSABLE UNIVERSAL SYNCHRONOUS ASYNCHRONOUS RECEIVER TRANSMITTER (USART) The USART can be configured in the following modes: * Asynchronous (full-duplex) * Synchronous - Master (half-duplex) * Synchronous - Slave (half-duplex) The Universal Synchronous Asynchronous Receiver Transmitter (USART) module is one of the two serial I/O modules. (USART is also known as a Serial Communications Interface or SCI.) The USART can be configured as a full duplex asynchronous system that can communicate with peripheral devices, such as CRT terminals and personal computers, or it can be configured as a half-duplex synchronous system that can communicate with peripheral devices, such as A/D or D/A integrated circuits, serial EEPROMs, etc. REGISTER 9-1: Bit SPEN (RCSTA<7>) and bits TRISC<7:6> have to be set in order to configure pins RC6/TX/CK and RC7/RX/DT as the Universal Synchronous Asynchronous Receiver Transmitter. The USART module also has a multi-processor communication capability using 9-bit address detection. TXSTA: TRANSMIT STATUS AND CONTROL REGISTER (ADDRESS: 98h) R/W-0 R/W-0 R/W-0 R/W-0 U-0 R/W-0 R-1 R/W-0 CSRC TX9 TXEN SYNC -- BRGH TRMT TX9D bit 7 bit 0 bit 7 CSRC: Clock Source Select bit Asynchronous mode: Don't care Synchronous mode: 1 = Master mode (clock generated internally from BRG) 0 = Slave mode (clock from external source) bit 6 TX9: 9-bit Transmit Enable bit 1 = Selects 9-bit transmission 0 = Selects 8-bit transmission bit 5 TXEN: Transmit Enable bit 1 = Transmit enabled 0 = Transmit disabled Note: SREN/CREN overrides TXEN in Sync mode. bit 4 SYNC: USART Mode Select bit 1 = Synchronous mode 0 = Asynchronous mode bit 3 Unimplemented: Read as '0' bit 2 BRGH: High Baud Rate Select bit Asynchronous mode: 1 = High speed 0 = Low speed Synchronous mode: Unused in this mode bit 1 TRMT: Transmit Shift Register Status bit 1 = TSR empty 0 = TSR full bit 0 TX9D: 9th bit of Transmit Data, can be parity bit Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared 2000-2013 Microchip Technology Inc. x = Bit is unknown DS30569C-page 61 PIC16F870/871 REGISTER 9-2: RCSTA: RECEIVE STATUS AND CONTROL REGISTER (ADDRESS 18h) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R-0 R-0 R-x SPEN RX9 SREN CREN ADDEN FERR OERR RX9D bit 7 bit 0 bit 7 SPEN: Serial Port Enable bit 1 = Serial port enabled (configures RC7/RX/DT and RC6/TX/CK pins as serial port pins) 0 = Serial port disabled bit 6 RX9: 9-bit Receive Enable bit 1 = Selects 9-bit reception 0 = Selects 8-bit reception bit 5 SREN: Single Receive Enable bit Asynchronous mode: Don't care Synchronous mode - master: 1 = Enables single receive 0 = Disables single receive This bit is cleared after reception is complete. Synchronous mode - slave: Don't care bit 4 CREN: Continuous Receive Enable bit Asynchronous mode: 1 = Enables continuous receive 0 = Disables continuous receive Synchronous mode: 1 = Enables continuous receive until enable bit CREN is cleared (CREN overrides SREN) 0 = Disables continuous receive bit 3 ADDEN: Address Detect Enable bit Asynchronous mode 9-bit (RX9 = 1): 1 = Enables address detection, enables interrupt and load of the receive buffer when RSR<8> is set 0 = Disables address detection, all bytes are received, and ninth bit can be used as parity bit bit 2 FERR: Framing Error bit 1 = Framing error (can be updated by reading RCREG register and receive next valid byte) 0 = No framing error bit 1 OERR: Overrun Error bit 1 = Overrun error (can be cleared by clearing bit CREN) 0 = No overrun error bit 0 RX9D: 9th bit of Received Data (can be parity bit, but must be calculated by user firmware) Legend: DS30569C-page 62 R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown 2000-2013 Microchip Technology Inc. PIC16F870/871 9.1 USART Baud Rate Generator (BRG) It may be advantageous to use the high baud rate (BRGH = 1), even for slower baud clocks. This is because the FOSC/(16(X + 1)) equation can reduce the baud rate error in some cases. The BRG supports both the Asynchronous and Synchronous modes of the USART. It is a dedicated 8-bit baud rate generator. The SPBRG register controls the period of a free running 8-bit timer. In Asynchronous mode, bit BRGH (TXSTA<2>) also controls the baud rate. In Synchronous mode, bit BRGH is ignored. Table 9-1 shows the formula for computation of the baud rate for different USART modes which only apply in Master mode (internal clock). Writing a new value to the SPBRG register causes the BRG timer to be reset (or cleared). This ensures the BRG does not wait for a timer overflow before outputting the new baud rate. 9.1.1 The data on the RC7/RX/DT pin is sampled three times by a majority detect circuit to determine if a high or a low level is present at the RX pin. Given the desired baud rate and FOSC, the nearest integer value for the SPBRG register can be calculated using the formula in Table 9-1. From this, the error in baud rate can be determined. TABLE 9-1: SAMPLING BAUD RATE FORMULA SYNC BRGH = 0 (Low Speed) BRGH = 1 (High Speed) 0 1 (Asynchronous) Baud Rate = FOSC/(64(X+1)) (Synchronous) Baud Rate = FOSC/(4(X+1)) Baud Rate = FOSC/(16(X+1)) N/A Legend: X = value in SPBRG (0 to 255) TABLE 9-2: Address REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other RESETS 98h TXSTA CSRC TX9 TXEN SYNC -- BRGH TRMT TX9D 0000 -010 0000 -010 18h RCSTA SPEN RX9 SREN CREN ADDEN FERR OERR RX9D 0000 000x 0000 000x 99h SPBRG 0000 0000 0000 0000 Legend: x = unknown, - = unimplemented, read as '0'. Shaded cells are not used by the BRG. Baud Rate Generator Register 2000-2013 Microchip Technology Inc. DS30569C-page 63 PIC16F870/871 TABLE 9-3: BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 0) FOSC = 20 MHz BAUD RATE (K) KBAUD % ERROR FOSC = 16 MHz SPBRG value (decimal) KBAUD % ERROR FOSC = 10 MHz SPBRG value (decimal) KBAUD % ERROR SPBRG value (decimal) 0.3 - - - - - - - - - 1.2 1.221 1.75 255 1.202 0.17 207 1.202 0.17 129 2.4 2.404 0.17 129 2.404 0.17 103 2.404 0.17 64 9.6 9.766 1.73 31 9.615 0.16 25 9.766 1.73 15 19.2 19.531 1.72 15 19.231 0.16 12 19.531 1.72 7 28.8 31.250 8.51 9 27.778 3.55 8 31.250 8.51 4 33.6 34.722 3.34 8 35.714 6.29 6 31.250 6.99 4 57.6 62.500 8.51 4 62.500 8.51 3 52.083 9.58 2 HIGH 1.221 - 255 0.977 - 255 0.610 - 255 LOW 312.500 - 0 250.000 - 0 156.250 - 0 FOSC = 4 MHz BAUD RATE (K) KBAUD FOSC = 3.6864 MHz % ERROR SPBRG value (decimal) KBAUD % ERROR SPBRG value (decimal) 0.3 0.300 0 207 0.3 0 191 1.2 1.202 0.17 51 1.2 0 47 2.4 2.404 0.17 25 2.4 0 23 9.6 8.929 6.99 6 9.6 0 5 19.2 20.833 8.51 2 19.2 0 2 28.8 31.250 8.51 1 28.8 0 1 33.6 - - - - - - 57.6 62.500 8.51 0 57.6 0 0 HIGH 0.244 - 255 0.225 - 255 LOW 62.500 - 0 57.6 - 0 DS30569C-page 64 2000-2013 Microchip Technology Inc. PIC16F870/871 TABLE 9-4: BAUD RATES FOR ASYNCHRONOUS MODE (BRGH = 1) FOSC = 20 MHz FOSC = 16 MHz BAUD RATE (K) KBAUD % ERROR SPBRG value (decimal) 0.3 - - 1.2 - - 2.4 - FOSC = 10 MHz KBAUD % ERROR SPBRG value (decimal) - - - - - - - - - KBAUD % ERROR SPBRG value (decimal) - - - - - - - - - - 2.441 1.71 255 9.6 9.615 0.16 129 9.615 0.16 103 9.615 0.16 64 19.2 19.231 0.16 64 19.231 0.16 51 19.531 1.72 31 28.8 29.070 0.94 42 29.412 2.13 33 28.409 1.36 21 33.6 33.784 0.55 36 33.333 0.79 29 32.895 2.10 18 57.6 59.524 3.34 20 58.824 2.13 16 56.818 1.36 10 HIGH 4.883 - 255 3.906 - 255 2.441 - 255 LOW 1250.000 - 0 1000.000 0 625.000 - 0 FOSC = 4 MHz BAUD RATE (K) KBAUD FOSC = 3.6864 MHz % ERROR SPBRG value (decimal) KBAUD % ERROR SPBRG value (decimal) 0.3 - - - - - - 1.2 1.202 0.17 207 1.2 0 191 2.4 2.404 0.17 103 2.4 0 95 9.6 9.615 0.16 25 9.6 0 23 19.2 19.231 0.16 12 19.2 0 11 28.8 27.798 3.55 8 28.8 0 7 33.6 35.714 6.29 6 32.9 2.04 6 57.6 62.500 8.51 3 57.6 0 3 HIGH 0.977 - 255 0.9 - 255 LOW 250.000 - 0 230.4 - 0 2000-2013 Microchip Technology Inc. DS30569C-page 65 PIC16F870/871 9.2 USART Asynchronous Mode enabled/disabled by setting/clearing enable bit TXIE ( PIE1<4>). Flag bit TXIF will be set, regardless of the state of enable bit TXIE and cannot be cleared in software. It will reset only when new data is loaded into the TXREG register. While flag bit TXIF indicates the status of the TXREG register, another bit, TRMT (TXSTA<1>), shows the status of the TSR register. Status bit TRMT is a read only bit, which is set when the TSR register is empty. No interrupt logic is tied to this bit, so the user has to poll this bit in order to determine if the TSR register is empty. In this mode, the USART uses standard non-return-tozero (NRZ) format (one START bit, eight or nine data bits, and one STOP bit). The most common data format is 8-bits. An on-chip, dedicated, 8-bit baud rate generator can be used to derive standard baud rate frequencies from the oscillator. The USART transmits and receives the LSb first. The transmitter and receiver are functionally independent, but use the same data format and baud rate. The baud rate generator produces a clock, either x16 or x64 of the bit shift rate, depending on bit BRGH (TXSTA<2>). Parity is not supported by the hardware, but can be implemented in software (and stored as the ninth data bit). Asynchronous mode is stopped during SLEEP. Note 1: The TSR register is not mapped in data memory, so it is not available to the user. 2: Flag bit TXIF is set when enable bit TXEN is set. TXIF is cleared by loading TXREG. Asynchronous mode is selected by clearing bit SYNC (TXSTA<4>). Transmission is enabled by setting enable bit TXEN (TXSTA<5>). The actual transmission will not occur until the TXREG register has been loaded with data and the baud rate generator (BRG) has produced a shift clock (Figure 9-2). The transmission can also be started by first loading the TXREG register and then setting enable bit TXEN. Normally, when transmission is first started, the TSR register is empty. At that point, transfer to the TXREG register will result in an immediate transfer to TSR, resulting in an empty TXREG. A back-to-back transfer is thus possible (Figure 9-3). Clearing enable bit TXEN during a transmission will cause the transmission to be aborted and will reset the transmitter. As a result, the RC6/TX/CK pin will revert to hi-impedance. The USART Asynchronous module consists of the following important elements: * * * * Baud Rate Generator Sampling Circuit Asynchronous Transmitter Asynchronous Receiver 9.2.1 USART ASYNCHRONOUS TRANSMITTER The USART transmitter block diagram is shown in Figure 9-1. The heart of the transmitter is the Transmit (Serial) Shift register (TSR). The Shift register obtains its data from the read/write transmit buffer, TXREG. The TXREG register is loaded with data in software. The TSR register is not loaded until the STOP bit has been transmitted from the previous load. As soon as the STOP bit is transmitted, the TSR is loaded with new data from the TXREG register (if available). Once the TXREG register transfers the data to the TSR register (occurs in one TCY), the TXREG register is empty and flag bit TXIF (PIR1<4>) is set. This interrupt can be FIGURE 9-1: In order to select 9-bit transmission, transmit bit TX9 (TXSTA<6>) should be set and the ninth bit should be written to TX9D (TXSTA<0>). The ninth bit must be written before writing the 8-bit data to the TXREG register. This is because a data write to the TXREG register can result in an immediate transfer of the data to the TSR register (if the TSR is empty). In such a case, an incorrect ninth data bit may be loaded in the TSR register. USART TRANSMIT BLOCK DIAGRAM Data Bus TXIF TXREG Register TXIE 8 MSb (8) LSb 0 Pin Buffer and Control TSR Register RC6/TX/CK pin Interrupt TXEN Baud Rate CLK TRMT SPEN SPBRG Baud Rate Generator TX9 TX9D DS30569C-page 66 2000-2013 Microchip Technology Inc. PIC16F870/871 When setting up an Asynchronous Transmission, follow these steps: 5. 1. 6. Initialize the SPBRG register for the appropriate baud rate. If a high speed baud rate is desired, set bit BRGH (Section 9.1). Enable the asynchronous serial port by clearing bit SYNC and setting bit SPEN. If interrupts are desired, then set enable bit TXIE. If 9-bit transmission is desired, then set transmit bit TX9. 2. 3. 4. FIGURE 9-2: Enable the transmission by setting bit TXEN, which will also set bit TXIF. If 9-bit transmission is selected, the ninth bit should be loaded in bit TX9D. Load data to the TXREG register (starts transmission). If using interrupts, ensure that GIE and PEIE (bits 7 and 6) of the INTCON register are set. 7. 8. ASYNCHRONOUS MASTER TRANSMISSION Write to TXREG Word 1 BRG Output (Shift Clock) RC6/TX/CK (pin) START Bit Bit 0 Bit 1 Word 1 TXIF bit (Transmit Buffer Reg. Empty Flag) TRMT bit (Transmit Shift Reg. Empty Flag) FIGURE 9-3: Bit 7/8 STOP Bit Word 1 Transmit Shift Reg ASYNCHRONOUS MASTER TRANSMISSION (BACK TO BACK) Write to TXREG Word 2 Word 1 BRG Output (Shift Clock) RC6/TX/CK (pin) START Bit Bit 0 TXIF bit (Interrupt Reg. Flag) TRMT bit (Transmit Shift Reg. Empty Flag) Note: Bit 7/8 Word 1 Transmit Shift Reg. STOP Bit START Bit Word 2 Bit 0 Word 2 Transmit Shift Reg. This timing diagram shows two consecutive transmissions. TABLE 9-5: Address Bit 1 Word 1 REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION Name 0Bh, 8Bh, INTCON 10Bh,18Bh Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other RESETS GIE PEIE T0IE INTE RBIE T0IF INTF R0IF 0000 000x 0000 000u PSPIF(1) ADIF RCIF TXIF -- CCP1IF TMR2IF TMR1IF 0000 -000 0000 -000 SPEN RX9 SREN CREN -- FERR OERR RX9D 0000 -00x 0000 -00x 0Ch PIR1 18h RCSTA 19h TXREG 8Ch PIE1 98h TXSTA 99h SPBRG Baud Rate Generator Register Legend: Note 1: x = unknown, - = unimplemented locations read as '0'. Shaded cells are not used for asynchronous transmission. Bits PSPIE and PSPIF are reserved on the PIC16F870; always maintain these bits clear. USART Transmit Register 0000 0000 0000 0000 PSPIE(1) ADIE RCIE TXIE -- CCP1IE TMR2IE TMR1IE 0000 -000 0000 -000 CSRC TX9 TXEN SYNC -- BRGH TRMT TX9D 0000 -010 0000 -010 0000 0000 0000 0000 2000-2013 Microchip Technology Inc. DS30569C-page 67 PIC16F870/871 9.2.2 USART ASYNCHRONOUS RECEIVER is possible for two bytes of data to be received and transferred to the RCREG FIFO and a third byte to begin shifting to the RSR register. On the detection of the STOP bit of the third byte, if the RCREG register is still full, the overrun error bit OERR (RCSTA<1>) will be set. The word in the RSR will be lost. The RCREG register can be read twice to retrieve the two bytes in the FIFO. Overrun bit OERR has to be cleared in software. This is done by resetting the receive logic (CREN is cleared and then set). If bit OERR is set, transfers from the RSR register to the RCREG register are inhibited, and no further data will be received. It is therefore, essential to clear error bit OERR if it is set. Framing error bit FERR (RCSTA<2>) is set if a STOP bit is detected as clear. Bit FERR and the 9th receive bit are buffered the same way as the receive data. Reading the RCREG will load bits RX9D and FERR with new values, therefore, it is essential for the user to read the RCSTA register before reading the RCREG register in order not to lose the old FERR and RX9D information. The receiver block diagram is shown in Figure 9-4. The data is received on the RC7/RX/DT pin and drives the data recovery block. The data recovery block is actually a high speed shifter, operating at x16 times the baud rate; whereas, the main receive serial shifter operates at the bit rate or at FOSC. Once Asynchronous mode is selected, reception is enabled by setting bit CREN (RCSTA<4>). The heart of the receiver is the Receive (Serial) Shift register (RSR). After sampling the STOP bit, the received data in the RSR is transferred to the RCREG register (if it is empty). If the transfer is complete, flag bit RCIF (PIR1<5>) is set. The actual interrupt can be enabled/disabled by setting/clearing enable bit RCIE (PIE1<5>). Flag bit RCIF is a read only bit, which is cleared by the hardware. It is cleared when the RCREG register has been read and is empty. The RCREG is a double-buffered register (i.e., it is a two-deep FIFO). It FIGURE 9-4: USART RECEIVE BLOCK DIAGRAM x64 Baud Rate CLK OERR FERR CREN FOSC SPBRG Baud Rate Generator 64 or 16 RSR Register MSb STOP (8) 7 1 LSb 0 START RC7/RX/DT Pin Buffer and Control Data Recovery RX9 RX9D SPEN Interrupt RCREG Register 8 RCIF Data Bus RCIE FIGURE 9-5: RX (pin) Rcv Shift Reg Rcv Buffer Reg Read Rcv Buffer Reg RCREG FIFO ASYNCHRONOUS RECEPTION START bit bit0 bit1 bit7/8 STOP bit START bit bit0 Word 1 RCREG bit7/8 STOP bit START bit bit7/8 STOP bit Word 2 RCREG RCIF (Interrupt Flag) OERR bit CREN Note: This timing diagram shows three words appearing on the RX input. The RCREG (receive buffer) is read after the third word, causing the OERR (overrun) bit to be set. DS30569C-page 68 2000-2013 Microchip Technology Inc. PIC16F870/871 When setting up an Asynchronous Reception, follow these steps: 1. 2. 3. 4. 5. 6. Flag bit RCIF will be set when reception is complete and an interrupt will be generated if enable bit RCIE is set. 7. Read the RCSTA register to get the ninth bit (if enabled) and determine if any error occurred during reception. 8. Read the 8-bit received data by reading the RCREG register. 9. If any error occurred, clear the error by clearing enable bit CREN. 10. If using interrupts, ensure that GIE and PEIE (bits 7 and 6) of the INTCON register are set. Initialize the SPBRG register for the appropriate baud rate. If a high speed baud rate is desired, set bit BRGH (Section 9.1). Enable the asynchronous serial port by clearing bit SYNC and setting bit SPEN. If interrupts are desired, then set enable bit RCIE. If 9-bit reception is desired, then set bit RX9. Enable the reception by setting bit CREN. TABLE 9-6: Address REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION Name 0Bh, 8Bh, INTCON 10Bh,18Bh 0Ch PIR1 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other RESETS GIE PEIE T0IE INTE RBIE T0IF INTF R0IF 0000 000x 0000 000u PSPIF(1) ADIF RCIF TXIF -- -000 0000 -000 0000 SPEN RX9 SREN CREN -- 0000 -00x 0000 -00x 0000 0000 0000 0000 0000 -000 0000 -000 0000 -010 0000 -010 0000 0000 0000 0000 18h RCSTA 1Ah RCREG USART Receive Register 8Ch PIE1 98h TXSTA PSPIE(1) ADIE RCIE TXIE -- CSRC TX9 TXEN SYNC -- Baud Rate Generator Register CCP1IF TMR2IF TMR1IF FERR OERR RX9D CCP1IE TMR2IE TMR1IE BRGH TRMT TX9D 99h SPBRG Legend: Note 1: x = unknown, - = unimplemented locations read as '0'. Shaded cells are not used for asynchronous reception. Bits PSPIE and PSPIF are reserved on the PIC16F870; always maintain these bits clear. 2000-2013 Microchip Technology Inc. DS30569C-page 69 PIC16F870/871 9.2.3 SETTING UP 9-BIT MODE WITH ADDRESS DETECT When setting up an Asynchronous Reception with Address Detect enabled: * Initialize the SPBRG register for the appropriate baud rate. If a high speed baud rate is desired, set bit BRGH. * Enable the asynchronous serial port by clearing bit SYNC and setting bit SPEN. * If interrupts are desired, then set enable bit RCIE. * Set bit RX9 to enable 9-bit reception. * Set ADDEN to enable address detect. * Enable the reception by setting enable bit CREN. FIGURE 9-6: * Flag bit RCIF will be set when reception is complete, and an interrupt will be generated if enable bit RCIE was set. * Read the RCSTA register to get the ninth bit and determine if any error occurred during reception. * Read the 8-bit received data by reading the RCREG register, to determine if the device is being addressed. * If any error occurred, clear the error by clearing enable bit CREN. * If the device has been addressed, clear the ADDEN bit to allow data bytes and address bytes to be read into the receive buffer, and interrupt the CPU. USART RECEIVE BLOCK DIAGRAM x64 Baud Rate CLK FERR OERR CREN FOSC SPBRG 64 Baud Rate Generator RSR Register MSb or 16 STOP (8) 7 1 LSb 0 START RC7/RX/DT Pin Buffer and Control Data Recovery RX9 8 SPEN RX9 ADDEN Enable Load of RX9 ADDEN RSR<8> Receive Buffer 8 RX9D RCREG Register FIFO 8 Interrupt RCIF Data Bus RCIE DS30569C-page 70 2000-2013 Microchip Technology Inc. PIC16F870/871 FIGURE 9-7: ASYNCHRONOUS RECEPTION WITH ADDRESS DETECT START bit bit0 RC7/RX/DT (pin) bit1 bit8 STOP bit START bit bit0 bit8 STOP bit Load RSR Bit8 = 0, Data Byte Word 1 RCREG Bit8 = 1, Address Byte Read RCIF Note: This timing diagram shows a data byte followed by an address byte. The data byte is not read into the RCREG (receive buffer) because ADDEN = 1. FIGURE 9-8: ASYNCHRONOUS RECEPTION WITH ADDRESS BYTE FIRST START bit bit0 RC7/RX/DT (pin) bit1 bit8 STOP bit START bit bit0 bit8 STOP bit Load RSR Bit8 = 1, Address Byte Word 1 RCREG Bit8 = 0, Data Byte Read RCIF Note: This timing diagram shows a data byte followed by an address byte. The data byte is not read into the RCREG (receive buffer) because ADDEN was not updated and still = 0. TABLE 9-7: Address REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION Name 0Bh, 8Bh, INTCON 10Bh,18Bh 0Ch PIR1 18h RCSTA 1Ah RCREG 8Ch PIE1 98h TXSTA 99h Legend: Note 1: SPBRG Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other RESETS GIE PEIE T0IE INTE RBIE T0IF INTF R0IF 0000 000x 0000 000u PSPIF(1) ADIF RCIF TXIF -- CCP1IF TMR2IF TMR1IF 0000 -000 0000 -000 SPEN RX9 SREN CREN ADDEN FERR OERR RX9D USART Receive Register PSPIE(1) ADIE RCIE TXIE -- CSRC TX9 TXEN SYNC -- Baud Rate Generator Register 0000 000x 0000 000x 0000 0000 0000 0000 CCP1IE TMR2IE TMR1IE 0000 -000 BRGH TRMT TX9D 0000 -000 0000 -010 0000 -010 0000 0000 0000 0000 x = unknown, - = unimplemented locations read as '0'. Shaded cells are not used for asynchronous reception. Bits PSPIE and PSPIF are reserved on the PIC16F870; always maintain these bits clear. 2000-2013 Microchip Technology Inc. DS30569C-page 71 PIC16F870/871 9.3 USART Synchronous Master Mode In Synchronous Master mode, the data is transmitted in a half-duplex manner (i.e., transmission and reception do not occur at the same time). When transmitting data, the reception is inhibited and vice versa. Synchronous mode is entered by setting bit SYNC (TXSTA<4>). In addition, enable bit SPEN (RCSTA<7>) is set in order to configure the RC6/TX/CK and RC7/RX/DT I/O pins to CK (clock) and DT (data) lines, respectively. The Master mode indicates that the processor transmits the master clock on the CK line. The Master mode is entered by setting bit CSRC (TXSTA<7>). 9.3.1 USART SYNCHRONOUS MASTER TRANSMISSION Clearing enable bit TXEN during a transmission will cause the transmission to be aborted and will reset the transmitter. The DT and CK pins will revert to hiimpedance. If either bit CREN or bit SREN is set during a transmission, the transmission is aborted and the DT pin reverts to a hi-impedance state (for a reception). The CK pin will remain an output if bit CSRC is set (internal clock). The transmitter logic, however, is not reset, although it is disconnected from the pins. In order to reset the transmitter, the user has to clear bit TXEN. If bit SREN is set (to interrupt an on-going transmission and receive a single word), then after the single word is received, bit SREN will be cleared and the serial port will revert back to transmitting, since bit TXEN is still set. The DT line will immediately switch from HiImpedance Receive mode to transmit and start driving. To avoid this, bit TXEN should be cleared. The USART transmitter block diagram is shown in Figure 9-6. The heart of the transmitter is the Transmit (Serial) Shift register (TSR). The Shift register obtains its data from the Read/Write Transmit Buffer register TXREG. The TXREG register is loaded with data in software. The TSR register is not loaded until the last bit has been transmitted from the previous load. As soon as the last bit is transmitted, the TSR is loaded with new data from the TXREG (if available). Once the TXREG register transfers the data to the TSR register (occurs in one TCYCLE), the TXREG is empty and interrupt bit TXIF (PIR1<4>) is set. The interrupt can be enabled/disabled by setting/clearing enable bit TXIE (PIE1<4>). Flag bit TXIF will be set, regardless of the state of enable bit TXIE and cannot be cleared in software. It will reset only when new data is loaded into the TXREG register. While flag bit TXIF indicates the status of the TXREG register, another bit TRMT (TXSTA<1>) shows the status of the TSR register. TRMT is a read only bit which is set when the TSR is empty. No interrupt logic is tied to this bit, so the user has to poll this bit in order to determine if the TSR register is empty. The TSR is not mapped in data memory, so it is not available to the user. In order to select 9-bit transmission, the TX9 (TXSTA<6>) bit should be set and the ninth bit should be written to bit TX9D (TXSTA<0>). The ninth bit must be written before writing the 8-bit data to the TXREG register. This is because a data write to the TXREG can result in an immediate transfer of the data to the TSR register (if the TSR is empty). If the TSR was empty and the TXREG was written before writing the "new" TX9D, the "present" value of bit TX9D is loaded. Transmission is enabled by setting enable bit TXEN (TXSTA<5>). The actual transmission will not occur until the TXREG register has been loaded with data. The first data bit will be shifted out on the next available rising edge of the clock on the CK line. Data out is stable around the falling edge of the synchronous clock (Figure 9-9). The transmission can also be started by first loading the TXREG register and then setting bit TXEN (Figure 9-10). This is advantageous when slow baud rates are selected, since the BRG is kept in RESET when bits TXEN, CREN and SREN are clear. Setting enable bit TXEN will start the BRG, creating a shift clock immediately. Normally, when transmission is first started, the TSR register is empty, so a transfer to the TXREG register will result in an immediate transfer to TSR, resulting in an empty TXREG. Back-to-back transfers are possible. 8. DS30569C-page 72 Steps to follow when setting up a Synchronous Master Transmission: 1. 2. 3. 4. 5. 6. 7. Initialize the SPBRG register for the appropriate baud rate (Section 9.1). Enable the synchronous master serial port by setting bits SYNC, SPEN and CSRC. If interrupts are desired, set enable bit TXIE. If 9-bit transmission is desired, set bit TX9. Enable the transmission by setting bit TXEN. If 9-bit transmission is selected, the ninth bit should be loaded in bit TX9D. Start transmission by loading data to the TXREG register. If using interrupts, ensure that GIE and PEIE (bits 7 and 6) of the INTCON register are set. 2000-2013 Microchip Technology Inc. PIC16F870/871 TABLE 9-8: Address REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other RESETS GIE PEIE T0IE INTE RBIE T0IF INTF R0IF 0000 000x 0000 000u PSPIF(1) ADIF RCIF TXIF -- CCP1IF TMR2IF TMR1IF 0000 -000 0000 -000 SPEN RX9 SREN CREN -- FERR OERR RX9D 0000 -00x 0000 -00x Name 0Bh, 8Bh, INTCON 10Bh,18Bh 0Ch PIR1 18h RCSTA 19h TXREG USART Transmit Register 8Ch PIE1 PSPIE(1) ADIE RCIE TXIE -- 98h TXSTA CSRC TX9 TXEN SYNC -- 99h SPBRG Legend: Note 1: CCP1IE TMR2IE TMR1IE BRGH TRMT TX9D Baud Rate Generator Register 0000 0000 0000 0000 0000 -000 0000 -000 0000 -010 0000 -010 0000 0000 0000 0000 x = unknown, - = unimplemented, read as '0'. Shaded cells are not used for synchronous master transmission. Bits PSPIE and PSPIF are reserved on the PIC16F870; always maintain these bits clear. FIGURE 9-9: SYNCHRONOUS TRANSMISSION Q1Q2 Q3Q4 Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2 Q3Q4 RC7/RX/DT pin bit 0 bit 1 Q3Q4 Q1Q2 Q3Q4 Q1Q2 Q3Q4 Q1Q2 Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4 bit 2 bit 7 bit 0 bit 1 bit 7 Word 2 Word 1 RC6/TX/CK pin Write to TXREG reg Write Word1 TXIF bit (Interrupt Flag) Write Word2 TRMT bit '1' TXEN bit '1' Note: Sync Master mode; SPBRG = 0. Continuous transmission of two 8-bit words. FIGURE 9-10: SYNCHRONOUS TRANSMISSION (THROUGH TXEN) RC7/RX/DT pin bit0 bit1 bit2 bit6 bit7 RC6/TX/CK pin Write to TXREG Reg TXIF bit TRMT bit TXEN bit 2000-2013 Microchip Technology Inc. DS30569C-page 73 PIC16F870/871 9.3.2 USART SYNCHRONOUS MASTER RECEPTION Once Synchronous mode is selected, reception is enabled by setting either enable bit SREN (RCSTA<5>), or enable bit CREN (RCSTA<4>). Data is sampled on the RC7/RX/DT pin on the falling edge of the clock. If enable bit SREN is set, then only a single word is received. If enable bit CREN is set, the reception is continuous until CREN is cleared. If both bits are set, CREN takes precedence. After clocking the last bit, the received data in the Receive Shift register (RSR) is transferred to the RCREG register (if it is empty). When the transfer is complete, interrupt flag bit RCIF (PIR1<5>) is set. The actual interrupt can be enabled/ disabled by setting/clearing enable bit RCIE (PIE1<5>). Flag bit RCIF is a read only bit, which is reset by the hardware. In this case, it is reset when the RCREG register has been read and is empty. The RCREG is a double-buffered register (i.e., it is a twodeep FIFO). It is possible for two bytes of data to be received and transferred to the RCREG FIFO and a third byte to begin shifting into the RSR register. On the clocking of the last bit of the third byte, if the RCREG register is still full, then overrun error bit OERR (RCSTA<1>) is set. The word in the RSR will be lost. The RCREG register can be read twice to retrieve the two bytes in the FIFO. Bit OERR has to be cleared in software (by clearing bit CREN). If bit OERR is set, transfers from the RSR to the RCREG are inhibited, so it is essential to clear bit OERR if it is set. The ninth receive bit is buffered the same way as the receive data. Reading the RCREG register will load bit RX9D with a new value, therefore, it is essential for the user to read the RCSTA register before reading RCREG, in order not to lose the old RX9D information. DS30569C-page 74 When setting up a Synchronous Master Reception: 1. Initialize the SPBRG register for the appropriate baud rate (Section 9.1). 2. Enable the synchronous master serial port by setting bits SYNC, SPEN and CSRC. 3. Ensure bits CREN and SREN are clear. 4. If interrupts are desired, then set enable bit RCIE. 5. If 9-bit reception is desired, then set bit RX9. 6. If a single reception is required, set bit SREN. For continuous reception, set bit CREN. 7. Interrupt flag bit RCIF will be set when reception is complete and an interrupt will be generated if enable bit RCIE was set. 8. Read the RCSTA register to get the ninth bit (if enabled) and determine if any error occurred during reception. 9. Read the 8-bit received data by reading the RCREG register. 10. If any error occurred, clear the error by clearing bit CREN. 11. If using interrupts, ensure that GIE and PEIE (bits 7 and 6) of the INTCON register are set. 2000-2013 Microchip Technology Inc. PIC16F870/871 TABLE 9-9: Address REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION Name 0Bh, 8Bh, INTCON 10Bh,18Bh Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other RESETS GIE PEIE T0IE INTE RBIE T0IF INTF R0IF 0000 000x 0000 000u PSPIF(1) ADIF RCIF TXIF -- CCP1IF TMR2IF TMR1IF 0000 -000 0000 -000 SPEN RX9 SREN CREN -- FERR OERR RX9D 0000 -00x 0000 -00x 0Ch PIR1 18h RCSTA 1Ah RCREG USART Receive Register 8Ch PIE1 PSPIE(1) ADIE RCIE TXIE -- 98h TXSTA CSRC TX9 TXEN SYNC -- 99h SPBRG Legend: Note 1: CCP1IE TMR2IE TMR1IE BRGH TRMT TX9D Baud Rate Generator Register 0000 0000 0000 0000 0000 -000 0000 -000 0000 -010 0000 -010 0000 0000 0000 0000 x = unknown, - = unimplemented, read as '0'. Shaded cells are not used for synchronous master reception. Bits PSPIE and PSPIF are reserved on the PIC16F870; always maintain these bits clear. FIGURE 9-11: SYNCHRONOUS RECEPTION (MASTER MODE, SREN) Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 RC7/RX/DT pin bit0 bit1 bit2 bit3 bit4 bit5 bit6 bit7 RC6/TX/CK pin Write to bit SREN SREN bit CREN bit '0' '0' RCIF bit (Interrupt) Read RXREG Note: Timing diagram demonstrates Sync Master mode with bit SREN = 1 and bit BRG = 0. 2000-2013 Microchip Technology Inc. DS30569C-page 75 PIC16F870/871 9.4 USART Synchronous Slave Mode When setting up a Synchronous Slave Transmission, follow these steps: Synchronous Slave mode differs from the Master mode in the fact that the shift clock is supplied externally at the RC6/TX/CK pin (instead of being supplied internally in Master mode). This allows the device to transfer or receive data while in SLEEP mode. Slave mode is entered by clearing bit CSRC (TXSTA<7>). 9.4.1 1. 2. 3. USART SYNCHRONOUS SLAVE TRANSMIT 4. 5. The operation of the Synchronous Master and Slave modes is identical, except in the case of the SLEEP mode. 6. If two words are written to the TXREG and then the SLEEP instruction is executed, the following will occur: 7. a) b) c) d) e) The first word will immediately transfer to the TSR register and transmit. The second word will remain in TXREG register. Flag bit TXIF will not be set. When the first word has been shifted out of TSR, the TXREG register will transfer the second word to the TSR and flag bit TXIF will now be set. If enable bit TXIE is set, the interrupt will wake the chip from SLEEP and if the global interrupt is enabled, the program will branch to the interrupt vector (0004h). TABLE 9-10: Address 8. REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION Name 0Bh, 8Bh, INTCON 10Bh,18Bh Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other RESETS GIE PEIE T0IE INTE RBIE T0IF INTF R0IF 0000 000x 0000 000u PSPIF(1) ADIF RCIF TXIF -- SPEN RX9 SREN CREN ADDEN 0Ch PIR1 18h RCSTA 19h TXREG USART Transmit Register 8Ch PIE1 PSPIE(1) ADIE RCIE TXIE -- 98h TXSTA CSRC TX9 TXEN SYNC -- 99h Legend: Note 1: Enable the synchronous slave serial port by setting bits SYNC and SPEN and clearing bit CSRC. Clear bits CREN and SREN. If interrupts are desired, then set enable bit TXIE. If 9-bit transmission is desired, then set bit TX9. Enable the transmission by setting enable bit TXEN. If 9-bit transmission is selected, the ninth bit should be loaded in bit TX9D. Start transmission by loading data to the TXREG register. If using interrupts, ensure that GIE and PEIE (bits 7 and 6) of the INTCON register are set. SPBRG Baud Rate Generator Register CCP1IF TMR2IF TMR1IF 0000 -000 FERR OERR RX9D 0000 000x 0000 -000 0000 000x 0000 0000 0000 0000 CCP1IE TMR2IE TMR1IE 0000 -000 0000 -000 BRGH TRMT TX9D 0000 -010 0000 -010 0000 0000 0000 0000 x = unknown, - = unimplemented, read as '0'. Shaded cells are not used for synchronous slave transmission. Bits PSPIE and PSPIF are reserved on the PIC16F870; always maintain these bits clear. DS30569C-page 76 2000-2013 Microchip Technology Inc. PIC16F870/871 9.4.2 USART SYNCHRONOUS SLAVE RECEPTION When setting up a Synchronous Slave Reception, follow these steps: The operation of the Synchronous Master and Slave modes is identical, except in the case of the SLEEP mode. Bit SREN is a "don't care" in Slave mode. 1. If receive is enabled by setting bit CREN prior to the SLEEP instruction, then a word may be received during SLEEP. On completely receiving the word, the RSR register will transfer the data to the RCREG register and if enable bit RCIE bit is set, the interrupt generated will wake the chip from SLEEP. If the global interrupt is enabled, the program will branch to the interrupt vector (0004h). 2. 3. 4. 5. 6. 7. 8. 9. TABLE 9-11: Address REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION Name 0Bh, 8Bh, INTCON 10Bh,18Bh 0Ch PIR1 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on: POR, BOR Value on all other RESETS GIE PEIE T0IE INTE RBIE T0IF INTF R0IF 0000 000x 0000 000u PSPIF(1) ADIF RCIF TXIF -- CCP1IF TMR2IF SPEN RX9 SREN CREN ADDEN FERR OERR 18h RCSTA 1Ah RCREG USART Receive Register 8Ch PIE1 PSPIE(1) ADIE RCIE TXIE -- 98h TXSTA CSRC TX9 TXEN SYNC -- 99h Legend: Note 1: Enable the synchronous master serial port by setting bits SYNC and SPEN and clearing bit CSRC. If interrupts are desired, set enable bit RCIE. If 9-bit reception is desired, set bit RX9. To enable reception, set enable bit CREN. Flag bit RCIF will be set when reception is complete and an interrupt will be generated, if enable bit RCIE was set. Read the RCSTA register to get the ninth bit (if enabled) and determine if any error occurred during reception. Read the 8-bit received data by reading the RCREG register. If any error occurred, clear the error by clearing bit CREN. If using interrupts, ensure that GIE and PEIE (bits 7 and 6) of the INTCON register are set. SPBRG TMR1IF 0000 -000 0000 -000 RX9D 0000 000x 0000 000x 0000 0000 0000 0000 Baud Rate Generator Register CCP1IE TMR2IE TMR1IE 0000 -000 0000 -000 BRGH TRMT TX9D 0000 -010 0000 -010 0000 0000 0000 0000 x = unknown, - = unimplemented, read as '0'. Shaded cells are not used for synchronous slave reception. Bits PSPIE and PSPIF are reserved on the PIC16F870, always maintain these bits clear. 2000-2013 Microchip Technology Inc. DS30569C-page 77 PIC16F870/871 NOTES: DS30569C-page 78 2000-2013 Microchip Technology Inc. PIC16F870/871 10.0 ANALOG-TO-DIGITAL (A/D) CONVERTER MODULE The A/D module has four registers. These registers are: The Analog-to-Digital (A/D) Converter module has five inputs for the 28-pin devices and eight for the other devices. The analog input charges a sample and hold capacitor. The output of the sample and hold capacitor is the input into the converter. The converter then generates a digital result of this analog level via successive approximation. The A/D conversion of the analog input signal results in a corresponding 10-bit digital number. The A/D module has high and low voltage reference input that is software selectable to some combination of VDD, VSS, RA2, or RA3. The A/D converter has a unique feature of being able to operate while the device is in SLEEP mode. To operate in SLEEP, the A/D clock must be derived from the A/D's internal RC oscillator. REGISTER 10-1: * * * * A/D Result High Register (ADRESH) A/D Result Low Register (ADRESL) A/D Control Register0 (ADCON0) A/D Control Register1 (ADCON1) The ADCON0 register, shown in Register 10-1, controls the operation of the A/D module. The ADCON1 register, shown in Register 10-2, configures the functions of the port pins. The port pins can be configured as analog inputs (RA3 can also be the voltage reference), or as digital I/O. Additional information on using the A/D module can be found in the PIC(R) Mid-Range MCU Family Reference Manual (DS33023). ADCON0 REGISTER (ADDRESS: 1Fh) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 U-0 R/W-0 ADCS1 ADCS0 CHS2 CHS1 CHS0 GO/DONE -- ADON bit 7 bit 0 bit 7-6 ADCS1:ADCS0: A/D Conversion Clock Select bits 00 = FOSC/2 01 = FOSC/8 10 = FOSC/32 11 = FRC (clock derived from the internal A/D module RC oscillator) bit 5-3 CHS2:CHS0: Analog Channel Select bits 000 = Channel 0, (RA0/AN0) 010 = Channel 2, (RA2/AN2) 011 = Channel 3, (RA3/AN3) 100 = Channel 4, (RA5/AN4) 101 = Channel 5, (RE0/AN5)(1) 110 = Channel 6, (RE1/AN6)(1) 111 = Channel 7, (RE2/AN7)(1) bit 2 GO/DONE: A/D Conversion Status bit If ADON = 1: 1 = A/D conversion in progress (setting this bit starts the A/D conversion) 0 = A/D conversion not in progress (this bit is automatically cleared by hardware when the A/D conversion is complete) bit 1 Unimplemented: Read as '0' bit 0 ADON: A/D On bit 1 = A/D converter module is operating 0 = A/D converter module is shut-off and consumes no operating current Note 1: These channels are not available on the PIC16F870 device. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared 2000-2013 Microchip Technology Inc. x = Bit is unknown DS30569C-page 79 PIC16F870/871 REGISTER 10-2: ADCON1 REGISTER (ADDRESS: 9Fh) U-0 U-0 R/W-0 U-0 R/W-0 R/W-0 R/W-0 R/W-0 ADFM -- -- -- PCFG3 PCFG2 PCFG1 PCFG0 bit 7 bit 0 bit 7 ADFM: A/D Result Format Select bit 1 = Right justified. 6 Most Significant bits of ADRESH are read as `0'. 0 = Left justified. 6 Least Significant bits of ADRESL are read as `0'. bit 6-4 Unimplemented: Read as '0' bit 3-0 PCFG3:PCFG0: A/D Port Configuration Control bits: PCFG3: AN7(1) AN6(1) AN5(1) RE2 RE1 RE0 PCFG0 AN4 RA5 AN3 RA3 AN2 RA2 AN1 RA1 AN0 RA0 VREF+ VREF- CHAN/ Refs(2) 0000 A A A A A A A A VDD VSS 8/0 0001 A A A A VREF+ A A A RA3 VSS 7/1 0010 D D D A A A A A VDD VSS 5/0 0011 D D D A VREF+ A A A RA3 VSS 4/1 0100 D D D D A D A A VDD VSS 3/0 0101 D D D D VREF+ D A A RA3 VSS 2/1 011x D D D D D D D D VDD VSS 0/0 1000 A A A A VREF+ VREF- A A RA3 RA2 6/2 6/0 1001 D D A A A A A A VDD VSS 1010 D D A A VREF+ A A A RA3 VSS 5/1 1011 D D A A VREF+ VREF- A A RA3 RA2 4/2 1100 D D D A VREF+ VREF- A A RA3 RA2 3/2 1101 D D D D VREF+ VREF- A A RA3 RA2 2/2 1110 D D D D D D D A VDD VSS 1/0 1111 D D D D VREF+ VREF- D A RA3 RA2 1/2 A = Analog input D = Digital I/O Note 1: These channels are not available on the PIC16F870 device. 2: This column indicates the number of analog channels available as A/D inputs and the number of analog channels used as voltage reference inputs. Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared The ADRESH:ADRESL registers contain the 10-bit result of the A/D conversion. When the A/D conversion is complete, the result is loaded into this A/D result register pair, the GO/DONE bit (ADCON0<2>) is cleared and the A/D interrupt flag bit ADIF is set. The block diagram of the A/D module is shown in Figure 10-1. x = Bit is unknown To determine sample time, see Section 10.1. After this acquisition time has elapsed, the A/D conversion can be started. After the A/D module has been configured as desired, the selected channel must be acquired before the conversion is started. The analog input channels must have their corresponding TRIS bits selected as inputs. DS30569C-page 80 2000-2013 Microchip Technology Inc. PIC16F870/871 These steps should be followed for doing an A/D Conversion: 1. 2. 3. 4. Configure the A/D module: * Configure analog pins/voltage reference and digital I/O (ADCON1) * Select A/D input channel (ADCON0) * Select A/D conversion clock (ADCON0) * Turn on A/D module (ADCON0) Configure A/D interrupt (if desired): * Clear ADIF bit * Set ADIE bit * Set PEIE bit * Set GIE bit FIGURE 10-1: 5. 6. 7. Wait the required acquisition time. Start conversion: * Set GO/DONE bit (ADCON0) Wait for A/D conversion to complete, by either: * Polling for the GO/DONE bit to be cleared (with interrupts enabled); OR * Waiting for the A/D interrupt Read A/D Result register pair (ADRESH:ADRESL), clear bit ADIF if required. For the next conversion, go to step 1 or step 2, as required. The A/D conversion time per bit is defined as TAD. A minimum wait of 2 TAD is required before the next acquisition starts. A/D BLOCK DIAGRAM CHS2:CHS0 111 110 101 RE2/AN7(1) RE1/AN6(1) RE0/AN5(1) 100 RA5/AN4 VAIN 011 (Input Voltage) RA3/AN3/VREF+ 010 RA2/AN2/VREF- A/D Converter 001 RA1/AN1 VDD 000 RA0/AN0 VREF+ (Reference Voltage) PCFG3:PCFG0 VREF(Reference Voltage) VSS PCFG3:PCFG0 Note 1: Not available on the PIC16F870 device. 2000-2013 Microchip Technology Inc. DS30569C-page 81 PIC16F870/871 10.1 A/D Acquisition Requirements For the A/D converter to meet its specified accuracy, the charge holding capacitor (CHOLD) must be allowed to fully charge to the input channel voltage level. The analog input model is shown in Figure 10-2. The source impedance (RS) and the internal sampling switch (RSS) impedance directly affect the time required to charge the capacitor CHOLD. The sampling switch (RSS) impedance varies over the device voltage (VDD), see Figure 10-2. The maximum recommended impedance for analog sources is 10 k. As the impedance is decreased, the acquisition time may EQUATION 10-1: TACQ TC TACQ be decreased. After the analog input channel is selected (changed), this acquisition must be done before the conversion can be started. To calculate the minimum acquisition time, Equation 10-1 may be used. This equation assumes that 1/2 LSb error is used (1024 steps for the A/D). The 1/2 LSb error is the maximum error allowed for the A/D to meet its specified resolution. To calculate the minimum acquisition time, TACQ, see the PIC(R) Mid-Range MCU Family Reference Manual (DS33023). ACQUISITION TIME = Amplifier Settling Time + Hold Capacitor Charging Time + Temperature Coefficient = = = = = = = TAMP + TC + TCOFF 2 s + TC + [(Temperature - 25C)(0.05 s/C)] CHOLD (RIC + RSS + RS) In(1/2047) - 120 pF (1 k + 7 k + 10 k) In(0.0004885) 16.47 s 2 s + 16.47 s + [(50C - 25C)(0.05 s/C) 19.72 s Note 1: The reference voltage (VREF) has no effect on the equation, since it cancels itself out. 2: The charge holding capacitor (CHOLD) is not discharged after each conversion. 3: The maximum recommended impedance for analog sources is 10 k. This is required to meet the pin leakage specification. 4: After a conversion has completed, a 2.0 TAD delay must complete before acquisition can begin again. During this time, the holding capacitor is not connected to the selected A/D input channel. FIGURE 10-2: ANALOG INPUT MODEL VDD RS VA ANx CPIN 5 pF VT = 0.6V VT = 0.6V RIC 1k Sampling Switch SS RSS CHOLD = DAC capacitance = 120 pF I LEAKAGE 500 nA VSS Legend CPIN = input capacitance VT = threshold voltage I LEAKAGE = leakage current at the pin due to various junctions RIC = interconnect resistance SS = sampling switch CHOLD = sample/hold capacitance (from DAC) DS30569C-page 82 6V 5V VDD 4V 3V 2V 5 6 7 8 9 10 11 Sampling Switch (k) 2000-2013 Microchip Technology Inc. PIC16F870/871 10.2 Selecting the A/D Conversion Clock For correct A/D conversions, the A/D conversion clock (TAD) must be selected to ensure a minimum TAD time of 1.6 s. The A/D conversion time per bit is defined as TAD. The A/D conversion requires a minimum 12 TAD per 10-bit conversion. The source of the A/D conversion clock is software selected. The four possible options for TAD are: * * * * Table 10-1 shows the resultant TAD times derived from the device operating frequencies and the A/D clock source selected. 2 TOSC 8 TOSC 32 TOSC Internal A/D module RC oscillator (2-6 s) TABLE 10-1: TAD vs. MAXIMUM DEVICE OPERATING FREQUENCIES (STANDARD DEVICES (C)) AD Clock Source (TAD) Note 1: 2: 3: 10.3 Maximum Device Frequency Operation ADCS1:ADCS0 Max. 2 TOSC 00 1.25 MHz 8 TOSC 01 5 MHz 32 TOSC 10 20 MHz RC(1, 2, 3) 11 (Note 1) The RC source has a typical TAD time of 4 s, but can vary between 2-6 s. When the device frequencies are greater than 1 MHz, the RC A/D conversion clock source is only recommended for SLEEP operation. For extended voltage devices (LC), please refer to the Electrical Characteristics (Section 14.1 and 14.2). Configuring Analog Port Pins The ADCON1 and TRIS registers control the operation of the A/D port pins. The port pins that are desired as analog inputs must have their corresponding TRIS bits set (input). If the TRIS bit is cleared (output), the digital output level (VOH or VOL) will be converted. The A/D operation is independent of the state of the CHS2:CHS0 bits and the TRIS bits. 2000-2013 Microchip Technology Inc. Note 1: When reading the port register, any pin configured as an analog input channel will read as cleared (a low level). Pins configured as digital inputs will convert an analog input. Analog levels on a digitally configured input will not affect the conversion accuracy. 2: Analog levels on any pin that is defined as a digital input (including the AN7:AN0 pins), may cause the input buffer to consume current that is out of the device specifications. DS30569C-page 83 PIC16F870/871 10.4 A/D Conversions acquisition is started. After this 2 TAD wait, acquisition on the selected channel is automatically started. The GO/DONE bit can then be set to start the conversion. Clearing the GO/DONE bit during a conversion will abort the current conversion. The A/D result register pair will NOT be updated with the partially completed A/D conversion sample. That is, the ADRESH:ADRESL registers will continue to contain the value of the last completed conversion (or the last value written to the ADRESH:ADRESL registers). After the A/D conversion is aborted, a 2 TAD wait is required before the next FIGURE 10-3: In Figure 10-3, after the GO bit is set, the first time segment has a minimum of TCY and a maximum of TAD. Note: The GO/DONE bit should NOT be set in the same instruction that turns on the A/D. A/D CONVERSION TAD CYCLES TCY to TAD TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 b9 b8 b7 b6 b5 b4 b3 TAD9 TAD10 TAD11 b2 b1 b0 Conversion starts Holding capacitor is disconnected from analog input (typically 100 ns) Set GO bit 10.4.1 ADRES is loaded GO bit is cleared ADIF bit is set Holding capacitor is connected to analog input A/D RESULT REGISTERS The ADRESH:ADRESL register pair is the location where the 10-bit A/D result is loaded at the completion of the A/D conversion. This register pair is 16-bits wide. The A/D module gives the flexibility to left or right justify the 10-bit result in the 16-bit result register. The A/D For- FIGURE 10-4: mat Select bit (ADFM) controls this justification. Figure 10-4 shows the operation of the A/D result justification. The extra bits are loaded with `0'. When an A/D result will not overwrite these locations (A/D disable), these registers may be used as two general purpose 8-bit registers. A/D RESULT JUSTIFICATION 10-bit Result ADFM = 0 ADFM = 1 7 0 2107 7 0765 0000 00 0000 00 ADRESH ADRESL 10-bit Result Right Justified DS30569C-page 84 0 ADRESH ADRESL 10-bit Result Left Justified 2000-2013 Microchip Technology Inc. PIC16F870/871 10.5 A/D Operation During SLEEP Turning off the A/D places the A/D module in its lowest current consumption state. The A/D module can operate during SLEEP mode. This requires that the A/D clock source be set to RC (ADCS1:ADCS0 = 11). When the RC clock source is selected, the A/D module waits one instruction cycle before starting the conversion. This allows the SLEEP instruction to be executed, which eliminates all digital switching noise from the conversion. When the conversion is completed, the GO/DONE bit will be cleared and the result loaded into the ADRES register. If the A/D interrupt is enabled, the device will wake-up from SLEEP. If the A/D interrupt is not enabled, the A/D module will then be turned off, although the ADON bit will remain set. Note: 10.6 Effects of a RESET A device RESET forces all registers to their RESET state. This forces the A/D module to be turned off, and any conversion is aborted. All A/D input pins are configured as analog inputs. When the A/D clock source is another clock option (not RC), a SLEEP instruction will cause the present conversion to be aborted and the A/D module to be turned off, though the ADON bit will remain set. TABLE 10-2: For the A/D module to operate in SLEEP, the A/D clock source must be set to RC (ADCS1:ADCS0 = 11). To allow the conversion to occur during SLEEP, ensure the SLEEP instruction immediately follows the instruction that sets the GO/DONE bit. The value that is in the ADRESH:ADRESL registers is not modified for a Power-on Reset. The ADRESH:ADRESL registers will contain unknown data after a Power-on Reset. REGISTERS/BITS ASSOCIATED WITH A/D Value on MCLR, WDT Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR 0Bh,8Bh, INTCON 10Bh,18Bh GIE PEIE T0IE INTE RBIE T0IF INTF RBIF 0000 000x 0000 000u Address 0Ch PIR1 PSPIF(1) ADIF RCIF TXIF -- CCP1IF TMR2IF TMR1IF 0000 -000 0000 -000 8Ch PIE1 PSPIE(1) ADIE RCIE TXIE -- CCP1IE TMR2IE TMR1IE 0000 -000 0000 -000 1Eh ADRESH A/D Result Register High Byte xxxx xxxx uuuu uuuu 9Eh ADRESL A/D Result Register Low Byte xxxx xxxx uuuu uuuu ADCS0 CHS2 CHS1 CHS0 GO/DONE -- ADON 0000 00-0 0000 00-0 -- PCFG3 PCFG2 PCFG1 PCFG0 --0- 0000 1Fh ADCON0 ADCS1 9Fh ADCON1 ADFM -- 85h TRISA -- -- PORTA Data Direction Register --11 1111 --11 1111 05h PORTA -- -- PORTA Data Latch when written: PORTA pins when read --0x 0000 --0u 0000 89h(1) TRISE IBF OBF IBOV PSPMODE -- 09h(1) PORTE -- -- -- -- -- Legend: Note 1: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used for A/D conversion. These registers/bits are not available on the 28-pin devices. 2000-2013 Microchip Technology Inc. -- PORTE Data Direction bits RE2 RE1 RE0 --0- 0000 0000 -111 0000 -111 ---- -xxx ---- -uuu DS30569C-page 85 PIC16F870/871 NOTES: DS30569C-page 86 2000-2013 Microchip Technology Inc. PIC16F870/871 11.0 SPECIAL FEATURES OF THE CPU The PIC16F870/871 devices have a host of features intended to maximize system reliability, minimize cost through elimination of external components, provide Power Saving Operating modes and offer code protection. These are: * Oscillator Selection * RESET - Power-on Reset (POR) - Power-up Timer (PWRT) - Oscillator Start-up Timer (OST) - Brown-out Reset (BOR) * Interrupts * Watchdog Timer (WDT) * SLEEP * Code Protection * ID Locations * In-Circuit Serial Programming * Low Voltage In-Circuit Serial Programming * In-Circuit Debugger SLEEP mode is designed to offer a very low current Power-down mode. The user can wake-up from SLEEP through external RESET, Watchdog Timer Wake-up, or through an interrupt. Several oscillator options are also made available to allow the part to fit the application. The RC oscillator option saves system cost while the LP crystal option saves power. A set of configuration bits is used to select various options. Additional information on special features is available in the PIC(R) Mid-Range MCU Family Reference Manual (DS33023). 11.1 Configuration Bits The configuration bits can be programmed (read as '0'), or left unprogrammed (read as '1'), to select various device configurations. The erased, or unprogrammed value of the configuration word is 3FFFh. These bits are mapped in program memory location 2007h. It is important to note that address 2007h is beyond the user program memory space, which can be accessed only during programming. PIC16F870/871 devices have a Watchdog Timer, which can be shut-off only through configuration bits. It runs off its own RC oscillator for added reliability. There are two timers that offer necessary delays on power-up. One is the Oscillator Start-up Timer (OST), intended to keep the chip in RESET until the crystal oscillator is stable. The other is the Power-up Timer (PWRT), which provides a fixed delay of 72 ms (nominal) on power-up only. It is designed to keep the part in RESET while the power supply stabilizes. With these two timers on-chip, most applications need no external RESET circuitry. 2000-2013 Microchip Technology Inc. DS30569C-page 87 PIC16F870/871 REGISTER 11-1: CP1 CP0 CONFIGURATION WORD (ADDRESS 2007h)(1) DEBUG -- WRT CPD LVP BOREN CP1 CP0 PWRTEN WDTEN FOSC1 FOSC0 bit 13 bit 0 (2) bit 13-12, bit 5-4 CP1:CP0: FLASH Program Memory Code Protection bits 11 = Code protection off 10 = Not supported 01 = Not supported 00 = Code protection on bit 11 DEBUG: In-Circuit Debugger Mode 1 = In-Circuit Debugger disabled, RB6 and RB7 are general purpose I/O pins 0 = In-Circuit Debugger enabled, RB6 and RB7 are dedicated to the debugger bit 10 Unimplemented: Read as `1' bit 9 WRT: FLASH Program Memory Write Enable 1 = Unprotected program memory may be written to by EECON control 0 = Unprotected program memory may not be written to by EECON control bit 8 CPD: Data EE Memory Code Protection 1 = Code protection off 0 = Data EEPROM memory code protected bit 7 LVP: Low Voltage In-Circuit Serial Programming Enable bit 1 = RB3/PGM pin has PGM function, low voltage programming enabled 0 = RB3 is digital I/O, HV on MCLR must be used for programming bit 6 BOREN: Brown-out Reset Enable bit(3) 1 = BOR enabled 0 = BOR disabled bit 3 PWRTEN: Power-up Timer Enable bit(3) 1 = PWRT disabled 0 = PWRT enabled bit 2 WDTEN: Watchdog Timer Enable bit 1 = WDT enabled 0 = WDT disabled bit 1-0 FOSC1:FOSC0: Oscillator Selection bits 11 = RC oscillator 10 = HS oscillator 01 = XT oscillator 00 = LP oscillator Legend: R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR `1' = Bit is set `0' = Bit is cleared x = Bit is unknown Note 1: The erased (unprogrammed) value of the configuration word is 3FFFh. 2: All of the CP1:CP0 pairs have to be given the same value to enable the code protection scheme listed. 3: Enabling Brown-out Reset automatically enables Power-up Timer (PWRT), regardless of the value of bit PWRTEN. Ensure the Power-up Timer is enabled any time Brown-out Reset is enabled. DS30569C-page 88 2000-2013 Microchip Technology Inc. PIC16F870/871 11.2 FIGURE 11-2: Oscillator Configurations 11.2.1 OSCILLATOR TYPES The PIC16F870/871 can be operated in four different Oscillator modes. The user can program two configuration bits (FOSC1 and FOSC0) to select one of these four modes: * * * * EXTERNAL CLOCK INPUT OPERATION (HS, XT OR LP OSC CONFIGURATION) LP XT HS RC Low Power Crystal Crystal/Resonator High Speed Crystal/Resonator Resistor/Capacitor 11.2.2 In XT, LP or HS modes, a crystal or ceramic resonator is connected to the OSC1/CLKI and OSC2/CLKO pins to establish oscillation (Figure 11-1). The PIC16F870/ 871 oscillator design requires the use of a parallel cut crystal. Use of a series cut crystal may give a frequency out of the crystal manufacturers specifications. When in XT, LP or HS modes, the device can have an external clock source to drive the OSC1/CLKI pin (Figure 11-2). CRYSTAL/CERAMIC RESONATOR OPERATION (HS, XT OR LP OSC CONFIGURATION) C1(1) OSC1 XTAL RF(3) OSC2 C2(1) Note 1: 2: 3: Rs (2) PIC16F870/871 OSC2 Open CRYSTAL OSCILLATOR/CERAMIC RESONATORS FIGURE 11-1: OSC1 Clock from Ext. System To Internal Logic SLEEP TABLE 11-1: CERAMIC RESONATORS Ranges Tested: Mode Freq. OSC1 OSC2 XT 455 kHz 2.0 MHz 4.0 MHz 68 - 100 pF 15 - 68 pF 15 - 68 pF 68 - 100 pF 15 - 68 pF 15 - 68 pF HS 8.0 MHz 16.0 MHz 10 - 68 pF 10 - 22 pF 10 - 68 pF 10 - 22 pF These values are for design guidance only. See notes following Table 11-2. Resonators Used: 455 kHz Panasonic EFO-A455K04B 0.3% 2.0 MHz Murata Erie CSA2.00MG 0.5% 4.0 MHz Murata Erie CSA4.00MG 0.5% 8.0 MHz Murata Erie CSA8.00MT 0.5% 16.0 MHz Murata Erie CSA16.00MX 0.5% All resonators used did not have built-in capacitors. PIC16F870/871 See Table 11-1 and Table 11-2 for recommended values of C1 and C2. A series resistor (Rs) may be required for AT strip cut crystals. RF varies with the crystal chosen. 2000-2013 Microchip Technology Inc. DS30569C-page 89 PIC16F870/871 TABLE 11-2: CAPACITOR SELECTION FOR CRYSTAL OSCILLATOR Osc Type Crystal Freq. Cap. Range C1 Cap. Range C2 LP 32 kHz 33 pF 33 pF 200 kHz 15 pF 15 pF 200 kHz 47-68 pF 47-68 pF 1 MHz 15 pF 15 pF XT HS 4 MHz 15 pF 15 pF 4 MHz 15 pF 15 pF 8 MHz 15-33 pF 15-33 pF 20 MHz 15-33 pF 15-33 pF These values are for design guidance only. See notes following this table. 11.2.3 RC OSCILLATOR For timing insensitive applications, the "RC" device option offers additional cost savings. The RC oscillator frequency is a function of the supply voltage, the resistor (REXT) and capacitor (CEXT) values, and the operating temperature. In addition to this, the oscillator frequency will vary from unit to unit due to normal process parameter variation. Furthermore, the difference in lead frame capacitance between package types will also affect the oscillation frequency, especially for low CEXT values. The user also needs to take into account variation due to tolerance of external R and C components used. Figure 11-3 shows how the R/C combination is connected to the PIC16F870/871. FIGURE 11-3: RC OSCILLATOR MODE VDD Crystals Used 32 kHz Epson C-001R32.768K-A 20 PPM 200 kHz STD XTL 200.000KHz 20 PPM 1 MHz ECS ECS-10-13-1 50 PPM 4 MHz ECS ECS-40-20-1 50 PPM CEXT VSS 8 MHz EPSON CA-301 8.000M-C 30 PPM 20 MHz EPSON CA-301 20.000M-C 30 PPM Note 1: Higher capacitance increases the stability of oscillator, but also increases the start-up time. REXT OSC1 Internal Clock PIC16F870/871 FOSC/4 OSC2/CLKO Recommended values: 3 k REXT 100 k CEXT > 20pF 2: Since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components. 3: Rs may be required in HS mode, as well as XT mode, to avoid overdriving crystals with low drive level specification. 4: When migrating from other PIC(R) devices, oscillator performance should be verified. DS30569C-page 90 2000-2013 Microchip Technology Inc. PIC16F870/871 11.3 RESET The PIC16F870/871 differentiates between various kinds of RESET: * * * * * * Power-on Reset (POR) MCLR Reset during normal operation MCLR Reset during SLEEP WDT Reset (during normal operation) WDT Wake-up (during SLEEP) Brown-out Reset (BOR) Some registers are not affected in any RESET condition. Their status is unknown on POR and unchanged in any other RESET. Most other registers are reset to a "RESET state" on Power-on Reset (POR), on the MCLR and WDT Reset, on MCLR Reset during FIGURE 11-4: SLEEP, and Brown-out Reset (BOR). They are not affected by a WDT Wake-up, which is viewed as the resumption of normal operation. The TO and PD bits are set or cleared differently in different RESET situations, as indicated in Table 11-4. These bits are used in software to determine the nature of the RESET. See Table 11-6 for a full description of RESET states of all registers. A simplified block diagram of the On-Chip Reset Circuit is shown in Figure 11-4. These devices have a MCLR noise filter in the MCLR Reset path. The filter will detect and ignore small pulses. It should be noted that a WDT Reset does not drive MCLR pin low. SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT External RESET MCLR WDT Module WDT SLEEP Time-out Reset VDD Rise Detect Power-on Reset VDD Brown-out Reset BOREN S OST/PWRT OST Chip_Reset 10-bit Ripple Counter R Q OSC1 (1) On-chip RC OSC PWRT 10-bit Ripple Counter Enable PWRT Enable OST Note 1: This is a separate oscillator from the RC oscillator of the CLKI pin. 2000-2013 Microchip Technology Inc. DS30569C-page 91 PIC16F870/871 11.4 Power-on Reset (POR) 11.7 A Power-on Reset pulse is generated on-chip when VDD rise is detected (in the range of 1.2V - 1.7V). To take advantage of the POR, tie the MCLR pin directly (or through a resistor) to VDD. This will eliminate external RC components usually needed to create a Power-on Reset. A maximum rise time for VDD is specified. See Electrical Specifications for details. When the device starts normal operation (exits the RESET condition), device operating parameters (voltage, frequency, temperature,...) must be met to ensure operation. If these conditions are not met, the device must be held in RESET until the operating conditions are met. Brown-out Reset may be used to meet the start-up conditions. For additional information, refer to Application Note, AN007, "Power-up Trouble Shooting" (DS00007). The configuration bit, BOREN, can enable or disable the Brown-out Reset circuit. If VDD falls below VBOR (parameter D005, about 4V) for longer than TBOR (parameter #35, about 100 S), the brown-out situation will reset the device. If VDD falls below VBOR for less than TBOR, a RESET may not occur. Once the brown-out occurs, the device will remain in Brown-out Reset until VDD rises above VBOR. The Power-up Timer then keeps the device in RESET for TPWRT (parameter #33, about 72 ms). If VDD should fall below VBOR during TPWRT, the Brown-out Reset process will restart when VDD rises above VBOR with the Power-up Timer Reset. The Power-up Timer is always enabled when the Brown-out Reset circuit is enabled, regardless of the state of the PWRT configuration bit. 11.8 11.5 Power-up Timer (PWRT) The Power-up Timer provides a fixed 72 ms nominal time-out on power-up only from the POR. The Powerup Timer operates on an internal RC oscillator. The chip is kept in RESET as long as the PWRT is active. The PWRT's time delay allows VDD to rise to an acceptable level. A configuration bit is provided to enable/disable the PWRT. The power-up time delay will vary from chip to chip due to VDD, temperature and process variation. See DC parameters for details (TPWRT, parameter #33). 11.6 Oscillator Start-up Timer (OST) The Oscillator Start-up Timer (OST) provides a delay of 1024 oscillator cycles (from OSC1 input) after the PWRT delay is over (if PWRT is enabled). This helps to ensure that the crystal oscillator or resonator has started and stabilized. The OST time-out is invoked only for XT, LP and HS modes and only on Power-on Reset or Wake-up from SLEEP. Brown-out Reset (BOR) Time-out Sequence On power-up, the time-out sequence is as follows: The PWRT delay starts (if enabled) when a POR Reset occurs. Then OST starts counting 1024 oscillator cycles when PWRT ends (LP, XT, HS). When the OST ends, the device comes out of RESET. If MCLR is kept low long enough, the time-outs will expire. Bringing MCLR high will begin execution immediately. This is useful for testing purposes or to synchronize more than one PIC16F870/871 device operating in parallel. Table 11-5 shows the RESET conditions for the STATUS, PCON and PC registers, while Table 11-6 shows the RESET conditions for all the registers. 11.9 Power Control/Status Register (PCON) The Power Control/Status Register, PCON, has up to two bits depending upon the device. Bit0 is Brown-out Reset Status bit, BOR. Bit BOR is unknown on a Power-on Reset. It must then be set by the user and checked on subsequent RESETS to see if bit BOR cleared, indicating a BOR occurred. When the Brown-out Reset is disabled, the state of the BOR bit is unpredictable and is, therefore, not valid at any time. Bit1 is POR (Power-on Reset Status bit). It is cleared on a Power-on Reset and unaffected otherwise. The user must set this bit following a Power-on Reset. TABLE 11-3: Oscillator Configuration XT, HS, LP RC DS30569C-page 92 TIME-OUT IN VARIOUS SITUATIONS Power-up Brown-out Wake-up from SLEEP 1024 TOSC 72 ms + 1024 TOSC 1024 TOSC -- 72 ms -- PWRTEN = 0 PWRTEN = 1 72 ms + 1024 TOSC 72 ms 2000-2013 Microchip Technology Inc. PIC16F870/871 TABLE 11-4: STATUS BITS AND THEIR SIGNIFICANCE POR BOR TO PD 0 x 1 1 Power-on Reset 0 x 0 x Illegal, TO is set on POR 0 x x 0 Illegal, PD is set on POR 1 0 1 1 Brown-out Reset 1 1 0 1 WDT Reset 1 1 0 0 WDT Wake-up 1 1 u u MCLR Reset during normal operation 1 1 0 MCLR Reset during SLEEP or interrupt wake-up from SLEEP 1 Legend: x = don't care, u = unchanged TABLE 11-5: RESET CONDITION FOR SPECIAL REGISTERS Program Counter STATUS Register PCON Register Power-on Reset 000h 0001 1xxx ---- --0x MCLR Reset during normal operation 000h 000u uuuu ---- --uu MCLR Reset during SLEEP 000h 0001 0uuu ---- --uu 000h 0000 1uuu ---- --uu PC + 1 uuu0 0uuu ---- --uu Condition WDT Reset WDT Wake-up Brown-out Reset Interrupt wake-up from SLEEP Legend: Note 1: 000h 0001 1uuu ---- --u0 PC + 1(1) uuu1 0uuu ---- --uu u = unchanged, x = unknown, - = unimplemented bit, read as '0' When the wake-up is due to an interrupt and the GIE bit is set, the PC is loaded with the interrupt vector (0004h). TABLE 11-6: INITIALIZATION CONDITIONS FOR ALL REGISTERS Devices Power-on Reset, Brown-out Reset MCLR Resets WDT Reset Wake-up via WDT or Interrupt W INDF TMR0 PIC16F870 PIC16F871 PIC16F870 PIC16F871 PIC16F870 PIC16F871 xxxx xxxx N/A xxxx xxxx uuuu uuuu N/A uuuu uuuu uuuu uuuu N/A uuuu uuuu PCL PIC16F870 PIC16F871 0000h 0000h PC + 1(2) STATUS FSR PORTA PORTB PORTC PORTD PORTE PCLATH PIC16F870 PIC16F870 PIC16F870 PIC16F870 PIC16F870 PIC16F870 PIC16F870 PIC16F870 Register PIC16F871 PIC16F871 PIC16F871 PIC16F871 PIC16F871 PIC16F871 PIC16F871 PIC16F871 0001 xxxx --0x xxxx xxxx xxxx ------0 1xxx xxxx 0000 xxxx xxxx xxxx -xxx 0000 000q uuuu --0u uuuu uuuu uuuu ------0 quuu(3) uuuu 0000 uuuu uuuu uuuu -uuu 0000 uuuq uuuu --uu uuuu uuuu uuuu ------u quuu(3) uuuu uuuu uuuu uuuu uuuu -uuu uuuu INTCON PIC16F870 PIC16F871 0000 000x 0000 000u uuuu uuuu(1) Legend: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition, r = reserved, maintain clear Note 1: One or more bits in INTCON, PIR1 and/or PIR2 will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIE bit is set, the PC is loaded with the interrupt vector (0004h). 3: See Table 11-5 for RESET value for specific condition. 2000-2013 Microchip Technology Inc. DS30569C-page 93 PIC16F870/871 TABLE 11-6: Register PIR1 INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED) Power-on Reset, Brown-out Reset MCLR Resets WDT Reset PIC16F871 r000 -000 r000 -000 ruuu -uuu(1) PIC16F870 PIC16F871 0000 -000 0000 -000 uuuu -uuu(1) Devices PIC16F870 Wake-up via WDT or Interrupt PIC16F870 PIC16F871 ---0 ------0 ------u ----(1) PIC16F870 PIC16F871 xxxx xxxx uuuu uuuu uuuu uuuu PIC16F870 PIC16F871 xxxx xxxx uuuu uuuu uuuu uuuu PIC16F870 PIC16F871 --00 0000 --uu uuuu --uu uuuu PIC16F870 PIC16F871 0000 0000 0000 0000 uuuu uuuu PIC16F870 PIC16F871 -000 0000 -000 0000 -uuu uuuu PIC16F870 PIC16F871 xxxx xxxx uuuu uuuu uuuu uuuu PIC16F870 PIC16F871 xxxx xxxx uuuu uuuu uuuu uuuu PIC16F870 PIC16F871 --00 0000 --00 0000 --uu uuuu PIC16F870 PIC16F871 0000 000x 0000 000x uuuu uuuu PIC16F870 PIC16F871 0000 0000 0000 0000 uuuu uuuu PIC16F870 PIC16F871 0000 0000 0000 0000 uuuu uuuu PIC16F870 PIC16F871 xxxx xxxx uuuu uuuu uuuu uuuu PIC16F870 PIC16F871 0000 00-0 0000 00-0 uuuu uu-u PIC16F870 PIC16F871 1111 1111 1111 1111 uuuu uuuu PIC16F870 PIC16F871 --11 1111 --11 1111 --uu uuuu PIC16F870 PIC16F871 1111 1111 1111 1111 uuuu uuuu PIC16F870 PIC16F871 1111 1111 1111 1111 uuuu uuuu PIC16F870 PIC16F871 1111 1111 1111 1111 uuuu uuuu PIC16F870 PIC16F871 0000 -111 0000 -111 uuuu -uuu PIC16F870 PIC16F871 r000 -000 r000 -000 ruuu -uuu PIC16F870 PIC16F871 0000 0000 0000 0000 uuuu uuuu PIC16F870 PIC16F871 ---0 ------0 ------u ---PIC16F870 PIC16F871 ---- --qq ---- --uu ---- --uu PIC16F870 PIC16F871 1111 1111 1111 1111 1111 1111 PIC16F870 PIC16F871 0000 -010 0000 -010 uuuu -uuu PIC16F870 PIC16F871 0000 0000 0000 0000 uuuu uuuu PIC16F870 PIC16F871 xxxx xxxx uuuu uuuu uuuu uuuu PIC16F870 PIC16F871 0--- 0000 0--- 0000 u--- uuuu PIC16F870 PIC16F871 0--- 0000 0--- 0000 u--- uuuu PIC16F870 PIC16F871 xxxx xxxx uuuu uuuu uuuu uuuu PIC16F870 PIC16F871 xxxx xxxx uuuu uuuu uuuu uuuu PIC16F870 PIC16F871 xxxx xxxx uuuu uuuu uuuu uuuu PIC16F870 PIC16F871 x--- x000 u--- u000 u--- uuuu PIC16F870 PIC16F871 ---- ------- ------- ---u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition, r = reserved, maintain clear One or more bits in INTCON, PIR1 and/or PIR2 will be affected (to cause wake-up). When the wake-up is due to an interrupt and the GIE bit is set, the PC is loaded with the interrupt vector (0004h). See Table 11-5 for RESET value for specific condition. PIR2 TMR1L TMR1H T1CON TMR2 T2CON CCPR1L CCPR1H CCP1CON RCSTA TXREG RCREG ADRESH ADCON0 OPTION_REG TRISA TRISB TRISC TRISD TRISE PIE1 PIE2 PCON PR2 TXSTA SPBRG ADRESL ADCON1 EEDATA EEADR EEDATH EEADRH EECON1 EECON2 Legend: Note 1: 2: 3: DS30569C-page 94 2000-2013 Microchip Technology Inc. PIC16F870/871 FIGURE 11-5: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD) VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1 FIGURE 11-6: VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2 FIGURE 11-7: VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET 2000-2013 Microchip Technology Inc. DS30569C-page 95 PIC16F870/871 FIGURE 11-8: SLOW RISE TIME (MCLR TIED TO VDD) 5V VDD 1V 0V MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET 11.10 Interrupts The PIC16F870/871 family has up to 14 sources of interrupt. The Interrupt Control register (INTCON) records individual interrupt requests in flag bits. It also has individual and global interrupt enable bits. Note: Individual interrupt flag bits are set, regardless of the status of their corresponding mask bit, or the GIE bit. A global interrupt enable bit, GIE (INTCON<7>), enables (if set) all unmasked interrupts, or disables (if cleared) all interrupts. When bit GIE is enabled, and an interrupt's flag bit and mask bit are set, the interrupt will vector immediately. Individual interrupts can be disabled through their corresponding enable bits in various registers. Individual interrupt bits are set, regardless of the status of the GIE bit. The GIE bit is cleared on RESET. The "return from interrupt" instruction, RETFIE, exits the interrupt routine as well as sets the GIE bit, which re-enables interrupts. The peripheral interrupt flags are contained in the special function registers, PIR1 and PIR2. The corresponding interrupt enable bits are contained in special function registers, PIE1 and PIE2, and the peripheral interrupt enable bit is contained in special function register, INTCON. When an interrupt is responded to, the GIE bit is cleared to disable any further interrupt, the return address is pushed onto the stack and the PC is loaded with 0004h. Once in the Interrupt Service Routine, the source(s) of the interrupt can be determined by polling the interrupt flag bits. The interrupt flag bit(s) must be cleared in software before re-enabling interrupts to avoid recursive interrupts. For external interrupt events, such as the INT pin or PORTB change interrupt, the interrupt latency will be three or four instruction cycles. The exact latency depends when the interrupt event occurs. The latency is the same for one or two-cycle instructions. Individual interrupt flag bits are set, regardless of the status of their corresponding mask bit, PEIE bit, or GIE bit. The RB0/INT pin interrupt, the RB port change interrupt, and the TMR0 overflow interrupt flags are contained in the INTCON register. DS30569C-page 96 2000-2013 Microchip Technology Inc. PIC16F870/871 FIGURE 11-9: INTERRUPT LOGIC EEIF EEIE PSPIF PSPIE ADIF ADIE Wake-up (If in SLEEP mode) T0IF T0IE INTF INTE RCIF RCIE TXIF TXIE Interrupt to CPU RBIF RBIE PEIE CCP1IF CCP1IE GIE TMR2IF TMR2IE TMR1IF TMR1IE The following table shows which devices have which interrupts. Device T0IF INTF RBIF PSPIF ADIF RCIF TXIF CCP1IF TMR2IF TMR1IF EEIF PIC18F870 Yes Yes Yes -- Yes Yes Yes Yes Yes Yes Yes PIC18F871 Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes 11.10.1 INT INTERRUPT External interrupt on the RB0/INT pin is edge triggered, either rising, if bit INTEDG (OPTION_REG<6>) is set, or falling, if the INTEDG bit is clear. When a valid edge appears on the RB0/INT pin, flag bit INTF (INTCON<1>) is set. This interrupt can be disabled by clearing enable bit INTE (INTCON<4>). Flag bit INTF must be cleared in software in the Interrupt Service Routine before re-enabling this interrupt. The INT interrupt can wake-up the processor from SLEEP, if bit INTE was set prior to going into SLEEP. The status of global interrupt enable bit, GIE, decides whether or not the processor branches to the interrupt vector following wake-up. See Section 11.13 for details on SLEEP mode. 2000-2013 Microchip Technology Inc. 11.10.2 TMR0 INTERRUPT An overflow (FFh 00h) in the TMR0 register will set flag bit T0IF (INTCON<2>). The interrupt can be enabled/disabled by setting/clearing enable bit T0IE (INTCON<5>) (Section 5.0). 11.10.3 PORTB INTCON CHANGE An input change on PORTB<7:4> sets flag bit RBIF (INTCON<0>). The interrupt can be enabled/disabled by setting/clearing enable bit RBIE (INTCON<4>) (Section 4.2). DS30569C-page 97 PIC16F870/871 11.11 Context Saving During Interrupts During an interrupt, only the return PC value is saved on the stack. Typically, users may wish to save key registers during an interrupt, (i.e., W register and STATUS register). This will have to be implemented in software. For the PIC16F870/871 devices, the register W_TEMP must be defined in both banks 0 and 1 and must be defined at the same offset from the bank base address (i.e., If W_TEMP is defined at 0x20 in bank 0, it must also be defined at 0xA0 in bank 1). The registers, PCLATH_TEMP and STATUS_TEMP, are only defined in bank 0. EXAMPLE 11-1: Since the upper 16 bytes of each bank are common in the PIC16F870/871 devices, temporary holding registers W_TEMP, STATUS_TEMP, and PCLATH_TEMP should be placed in here. These 16 locations don't require banking and therefore, make it easier for context save and restore. The same code shown in Example 11-1 can be used. SAVING STATUS, W, AND PCLATH REGISTERS IN RAM MOVWF SWAPF CLRF MOVWF MOVF MOVWF CLRF : :(ISR) : MOVF MOVWF SWAPF W_TEMP STATUS,W STATUS STATUS_TEMP PCLATH, W PCLATH_TEMP PCLATH MOVWF SWAPF SWAPF STATUS W_TEMP,F W_TEMP,W ;Copy ;Swap ;bank ;Save ;Only ;Save ;Page W to TEMP register status to be saved into W 0, regardless of current bank, Clears IRP,RP1,RP0 status to bank zero STATUS_TEMP register required if using pages 1, 2 and/or 3 PCLATH into W zero, regardless of current page ;(Insert user code here) PCLATH_TEMP, W PCLATH STATUS_TEMP,W DS30569C-page 98 ;Restore PCLATH ;Move W into PCLATH ;Swap STATUS_TEMP register into W ;(sets bank to original state) ;Move W into STATUS register ;Swap W_TEMP ;Swap W_TEMP into W 2000-2013 Microchip Technology Inc. PIC16F870/871 11.12 Watchdog Timer (WDT) WDT time-out period values may be found in the Electrical Specifications section under parameter #31. Values for the WDT prescaler (actually a postscaler, but shared with the Timer0 prescaler) may be assigned using the OPTION_REG register. The Watchdog Timer is a free running on-chip RC oscillator which does not require any external components. This RC oscillator is separate from the RC oscillator of the OSC1/CLKI pin. That means that the WDT will run, even if the clock on the OSC1/CLKI and OSC2/CLKO pins of the device has been stopped, for example, by execution of a SLEEP instruction. Note 1: The CLRWDT and SLEEP instructions clear the WDT and the postscaler, if assigned to the WDT, and prevent it from timing out and generating a device RESET condition. During normal operation, a WDT time-out generates a device RESET (Watchdog Timer Reset). If the device is in SLEEP mode, a WDT time-out causes the device to wake-up and continue with normal operation (Watchdog Timer Wake-up). The TO bit in the STATUS register will be cleared upon a Watchdog Timer time-out. 2: When a CLRWDT instruction is executed and the prescaler is assigned to the WDT, the prescaler count will be cleared, but the prescaler assignment is not changed. The WDT can be permanently disabled by clearing configuration bit WDTEN (Section 11.1). FIGURE 11-10: WATCHDOG TIMER BLOCK DIAGRAM From TMR0 Clock Source (Figure 5-1) 0 WDT Timer 1 Postscaler M U X 8 8 - to - 1 MUX PS2:PS0 PSA WDT Enable Bit To TMR0 (Figure 5-1) 0 1 MUX PSA WDT Time-out Note: PSA and PS2:PS0 are bits in the OPTION_REG register. TABLE 11-7: Address 2007h 81h,181h Legend: Note 1: SUMMARY OF WATCHDOG TIMER REGISTERS Name Config. bits OPTION_REG Bit 7 Bit 6 Bit 5 Bit 4 (1) BOREN(1) CP1 CP0 RBPU INTEDG T0CS T0SE Bit 3 Bit 2 PWRTEN(1) WDTEN PSA PS2 Bit 1 Bit 0 FOSC1 FOSC0 PS1 PS0 Shaded cells are not used by the Watchdog Timer. See Register 11-1 for operation of these bits. 2000-2013 Microchip Technology Inc. DS30569C-page 99 PIC16F870/871 11.13 Power-down Mode (SLEEP) Power-down mode is entered by executing a SLEEP instruction. If enabled, the Watchdog Timer will be cleared but keeps running, the PD bit (STATUS<3>) is cleared, the TO (STATUS<4>) bit is set, and the oscillator driver is turned off. The I/O ports maintain the status they had before the SLEEP instruction was executed (driving high, low, or hi-impedance). For lowest current consumption in this mode, place all I/O pins at either VDD or VSS, ensure no external circuitry is drawing current from the I/O pin, power-down the A/D and disable external clocks. Pull all I/O pins that are hi-impedance inputs, high or low externally, to avoid switching currents caused by floating inputs. The T0CKI input should also be at VDD or VSS for lowest current consumption. The contribution from on-chip pull-ups on PORTB should also be considered. The MCLR pin must be at a logic high level (VIHMC). 11.13.1 WAKE-UP FROM SLEEP The device can wake-up from SLEEP through one of the following events: 1. 2. 3. External RESET input on MCLR pin. Watchdog Timer Wake-up (if WDT was enabled). Interrupt from INT pin, RB port change or peripheral interrupt. External MCLR Reset will cause a device RESET. All other events are considered a continuation of program execution and cause a "wake-up". The TO and PD bits in the STATUS register can be used to determine the cause of device RESET. The PD bit, which is set on power-up, is cleared when SLEEP is invoked. The TO bit is cleared if a WDT time-out occurred and caused wake-up. When the SLEEP instruction is being executed, the next instruction (PC + 1) is pre-fetched. For the device to wake-up through an interrupt event, the corresponding interrupt enable bit must be set (enabled). Wake-up is regardless of the state of the GIE bit. If the GIE bit is clear (disabled), the device continues execution at the instruction after the SLEEP instruction. If the GIE bit is set (enabled), the device executes the instruction after the SLEEP instruction and then branches to the interrupt address (0004h). In cases where the execution of the instruction following SLEEP is not desirable, the user should have a NOP after the SLEEP instruction. 11.13.2 WAKE-UP USING INTERRUPTS When global interrupts are disabled (GIE cleared) and any interrupt source has both its interrupt enable bit and interrupt flag bit set, one of the following will occur: * If the interrupt occurs before the execution of a SLEEP instruction, the SLEEP instruction will complete as a NOP. Therefore, the WDT and WDT postscaler will not be cleared, the TO bit will not be set and PD bits will not be cleared. * If the interrupt occurs during or after the execution of a SLEEP instruction, the device will immediately wake-up from SLEEP. The SLEEP instruction will be completely executed before the wake-up. Therefore, the WDT and WDT postscaler will be cleared, the TO bit will be set and the PD bit will be cleared. Even if the flag bits were checked before executing a SLEEP instruction, it may be possible for flag bits to become set before the SLEEP instruction completes. To determine whether a SLEEP instruction executed, test the PD bit. If the PD bit is set, the SLEEP instruction was executed as a NOP. To ensure that the WDT is cleared, a CLRWDT instruction should be executed before a SLEEP instruction. The following peripheral interrupts can wake the device from SLEEP: 1. 2. 3. 4. 5. 6. 7. 8. 9. PSP read or write (PIC16F874/877 only). TMR1 interrupt. Timer1 must be operating as an asynchronous counter. CCP Capture mode interrupt. Special event trigger (Timer1 in Asynchronous mode using an external clock). SSP (START/STOP) bit detect interrupt. SSP transmit or receive in Slave mode (SPI/I2C). USART RX or TX (Synchronous Slave mode). A/D conversion (when A/D clock source is RC). EEPROM write operation completion Other peripherals cannot generate interrupts, since during SLEEP, no on-chip clocks are present. DS30569C-page 100 2000-2013 Microchip Technology Inc. PIC16F870/871 FIGURE 11-11: WAKE-UP FROM SLEEP THROUGH INTERRUPT Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 TOST(2) CLKO(4) INT pin INTF Flag (INTCON<1>) Interrupt Latency(2) GIE bit (INTCON<7>) Processor in SLEEP INSTRUCTION FLOW PC Instruction Fetched Instruction Executed Note 1: 2: 3: 4: PC PC+1 Inst(PC) = SLEEP Inst(PC - 1) PC+2 PC+2 Inst(PC + 1) Inst(PC + 2) SLEEP Inst(PC + 1) PC + 2 Dummy cycle 0004h 0005h Inst(0004h) Inst(0005h) Dummy cycle Inst(0004h) XT, HS or LP Oscillator mode assumed. TOST = 1024 TOSC (drawing not to scale). This delay will not be there for RC Osc mode. GIE = 1 assumed. In this case, after wake- up, the processor jumps to the interrupt routine. If GIE = 0, execution will continue in-line. CLKO is not available in these Osc modes, but shown here for timing reference. 11.14 In-Circuit Debugger When the DEBUG bit in the configuration word is programmed to a '0', the In-Circuit Debugger functionality is enabled. This function allows simple debugging functions when used with MPLAB(R) ICD. When the microcontroller has this feature enabled, some of the resources are not available for general use. Table 11-8 shows which features are consumed by the background debugger. TABLE 11-8: DEBUGGER RESOURCES I/O pins RB6, RB7 Stack 1 level Program Memory Address 0000h must be NOP 11.15 Program Verification/Code Protection If the code protection bit(s) have not been programmed, the on-chip program memory can be read out for verification purposes. 11.16 ID Locations Four memory locations (2000h - 2003h) are designated as ID locations, where the user can store checksum or other code identification numbers. These locations are not accessible during normal execution, but are readable and writable during program/verify. It is recommended that only the 4 Least Significant bits of the ID location are used. Last 100h words Data Memory 0x070 (0x0F0, 0x170, 0x1F0) 0x1EB - 0x1EF To use the In-Circuit Debugger function of the microcontroller, the design must implement In-Circuit Serial Programming connections to MCLR/VPP, VDD, GND, RB7 and RB6. This will interface to the In-Circuit Debugger module available from Microchip, or one of the third party development tool companies. 2000-2013 Microchip Technology Inc. DS30569C-page 101 PIC16F870/871 11.17 In-Circuit Serial Programming PIC16F870/871 microcontrollers can be serially programmed while in the end application circuit. This is simply done with two lines for clock and data and three other lines for power, ground, and the programming voltage. This allows customers to manufacture boards with unprogrammed devices, and then program the microcontroller just before shipping the product. This also allows the most recent firmware, or a custom firmware to be programmed. When using ICSP, the part must be supplied at 4.5V to 5.5V, if a bulk erase will be executed. This includes reprogramming of the code protect, both from an onstate to off-state. For all other cases of ICSP, the part may be programmed at the normal operating voltages. This means calibration values, unique user IDs, or user code can be reprogrammed or added. For complete details of serial programming, please refer to the EEPROM Memory Programming Specification for the PIC16F87X (DS39025). 11.18 Low Voltage ICSP Programming The LVP bit of the configuration word enables low voltage ICSP programming. This mode allows the microcontroller to be programmed via ICSP, using a VDD source in the operating voltage range. This only means that VPP does not have to be brought to VIHH, but can instead be left at the normal operating voltage. In this mode, the RB3/PGM pin is dedicated to the programming function and ceases to be a general purpose I/O pin. During programming, VDD is applied to the MCLR pin. To enter Programming mode, VDD must be applied to the RB3/PGM pin, provided the LVP bit is set. The LVP bit defaults to on (`1') from the factory. Note 1: The High Voltage Programming mode is always available, regardless of the state of the LVP bit, by applying VIHH to the MCLR pin. 2: While in Low Voltage ICSP mode, the RB3 pin can no longer be used as a general purpose I/O pin. 3: When using low voltage ICSP programming (LVP) and the pull-ups on PORTB are enabled, bit 3 in the TRISB register must be cleared to disable the pull-up on RB3 and ensure the proper operation of the device. 4: RB3 should not be allowed to float if LVP is enabled. An external pull-down device should be used to default the device to normal Operating mode. If RB3 floats high, the PIC16F870/871 devices will enter Programming mode. 5: LVP mode is enabled by default on all devices shipped from Microchip. It can be disabled by clearing the LVP bit in the CONFIG register. 6: Disabling LVP will provide maximum compatibility to other PIC16CXXX devices. If Low Voltage Programming mode is not used, the LVP bit can be programmed to a '0' and RB3/PGM becomes a digital I/O pin. However, the LVP bit may only be programmed when programming is entered with VIHH on MCLR. The LVP bit can only be charged when using high voltage on MCLR. It should be noted, that once the LVP bit is programmed to 0, only the High Voltage Programming mode is available and only High Voltage Programming mode can be used to program the device. When using low voltage ICSP, the part must be supplied at 4.5V to 5.5V, if a bulk erase will be executed. This includes reprogramming of the code protect bits from an on-state to off-state. For all other cases of low voltage ICSP, the part may be programmed at the normal operating voltage. This means calibration values, unique user IDs, or user code can be reprogrammed or added. DS30569C-page 102 2000-2013 Microchip Technology Inc. PIC16F870/871 12.0 INSTRUCTION SET SUMMARY Each PIC16F870/871 instruction is a 14-bit word, divided into an OPCODE, which specifies the instruction type, and one or more operands, which further specify the operation of the instruction. The PIC16F870/871 instruction set summary in Table 12-2 lists byte-oriented, bit-oriented, and literal and control operations. Table 12-1 shows the opcode field descriptions. For byte-oriented instructions, 'f' represents a file register designator and 'd' represents a destination designator. The file register designator specifies which file register is to be used by the instruction. The destination designator specifies where the result of the operation is to be placed. If 'd' is zero, the result is placed in the W register. If 'd' is one, the result is placed in the file register specified in the instruction. For bit-oriented instructions, 'b' represents a bit field designator which selects the number of the bit affected by the operation, while 'f' represents the address of the file in which the bit is located. For literal and control operations, 'k' represents an eight or eleven bit constant or literal value. TABLE 12-1: OPCODE FIELD DESCRIPTIONS Field Description f Register file address (0x00 to 0x7F) W Working register (accumulator) b Bit address within an 8-bit file register k Literal field, constant data or label x Don't care location (= 0 or 1). The assembler will generate code with x = 0. It is the recommended form of use for compatibility with all Microchip software tools. d Destination select; d = 0: store result in W, d = 1: store result in file register f. Default is d = 1. PC Program Counter TO Time-out bit PD Power-down bit The instruction set is highly orthogonal and is grouped into three basic categories: * Byte-oriented operations * Bit-oriented operations * Literal and control operations All instructions are executed within one single instruction cycle, unless a conditional test is true, or the program counter is changed as a result of an instruction. In this case, the execution takes two instruction cycles, with the second cycle executed as a NOP. One instruction cycle consists of four oscillator periods. Thus, for an oscillator frequency of 4 MHz, the normal instruction execution time is 1 s. If a conditional test is true, or the program counter is changed as a result of an instruction, the instruction execution time is 2 s. Table 12-2 lists the instructions recognized by the MPASMTM assembler. Figure 12-1 shows the general formats that the instructions can have. Note: To maintain upward compatibility with future PIC16F870/871 products, do not use the OPTION and TRIS instructions. All examples use the following format to represent a hexadecimal number: 0xhh where h signifies a hexadecimal digit. FIGURE 12-1: GENERAL FORMAT FOR INSTRUCTIONS Byte-oriented file register operations 13 8 7 6 OPCODE d f (FILE #) 0 d = 0 for destination W d = 1 for destination f f = 7-bit file register address Bit-oriented file register operations 13 10 9 7 6 OPCODE b (BIT #) 0 f (FILE #) b = 3-bit bit address f = 7-bit file register address Literal and control operations General 13 8 7 OPCODE 0 k (literal) k = 8-bit immediate value CALL and GOTO instructions only 13 11 OPCODE 10 0 k (literal) k = 11-bit immediate value A description of each instruction is available in the PIC(R) Mid-Range MCU Family Reference Manual (DS33023). 2000-2013 Microchip Technology Inc. DS30569C-page 103 PIC16F870/871 TABLE 12-2: PIC16F870/871 INSTRUCTION SET Mnemonic, Operands 14-Bit Opcode Description Cycles MSb LSb Status Affected Notes BYTE-ORIENTED FILE REGISTER OPERATIONS ADDWF ANDWF CLRF CLRW COMF DECF DECFSZ INCF INCFSZ IORWF MOVF MOVWF NOP RLF RRF SUBWF SWAPF XORWF f, d f, d f f, d f, d f, d f, d f, d f, d f, d f f, d f, d f, d f, d f, d Add W and f AND W with f Clear f Clear W Complement f Decrement f Decrement f, Skip if 0 Increment f Increment f, Skip if 0 Inclusive OR W with f Move f Move W to f No Operation Rotate Left f through Carry Rotate Right f through Carry Subtract W from f Swap nibbles in f Exclusive OR W with f BCF BSF BTFSC BTFSS f, b f, b f, b f, b Bit Clear f Bit Set f Bit Test f, Skip if Clear Bit Test f, Skip if Set 1 1 1 1 1 1 1(2) 1 1(2) 1 1 1 1 1 1 1 1 1 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 dfff dfff lfff 0xxx dfff dfff dfff dfff dfff dfff dfff lfff 0xx0 dfff dfff dfff dfff dfff ffff ffff ffff xxxx ffff ffff ffff ffff ffff ffff ffff ffff 0000 ffff ffff ffff ffff ffff 00bb 01bb 10bb 11bb bfff bfff bfff bfff ffff ffff ffff ffff 111x 1001 0kkk 0000 1kkk 1000 00xx 0000 01xx 0000 0000 110x 1010 kkkk kkkk kkkk 0110 kkkk kkkk kkkk 0000 kkkk 0000 0110 kkkk kkkk kkkk kkkk kkkk 0100 kkkk kkkk kkkk 1001 kkkk 1000 0011 kkkk kkkk 0111 0101 0001 0001 1001 0011 1011 1010 1111 0100 1000 0000 0000 1101 1100 0010 1110 0110 C,DC,Z Z Z Z Z Z Z Z Z C C C,DC,Z Z 1,2 1,2 2 1,2 1,2 1,2,3 1,2 1,2,3 1,2 1,2 1,2 1,2 1,2 1,2 1,2 BIT-ORIENTED FILE REGISTER OPERATIONS 1 1 1 (2) 1 (2) 01 01 01 01 1,2 1,2 3 3 LITERAL AND CONTROL OPERATIONS ADDLW ANDLW CALL CLRWDT GOTO IORLW MOVLW RETFIE RETLW RETURN SLEEP SUBLW XORLW Note 1: 2: 3: Note: k k k k k k k k k Add literal and W AND literal with W Call subroutine Clear Watchdog Timer Go to address Inclusive OR literal with W Move literal to W Return from interrupt Return with literal in W Return from Subroutine Go into Standby mode Subtract W from literal Exclusive OR literal with W 1 1 2 1 2 1 1 2 2 2 1 1 1 11 11 10 00 10 11 11 00 11 00 00 11 11 C,DC,Z Z TO,PD Z TO,PD C,DC,Z Z When an I/O register is modified as a function of itself ( e.g., MOVF PORTB, 1), the value used will be that value present on the pins themselves. For example, if the data latch is '1' for a pin configured as input and is driven low by an external device, the data will be written back with a '0'. If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be cleared if assigned to the Timer0 module. If Program Counter (PC) is modified, or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. Additional information on the mid-range instruction set is available in the PIC(R) Mid-Range MCU Family Reference Manual (DS33023). DS30569C-page 104 2000-2013 Microchip Technology Inc. PIC16F870/871 12.1 Instruction Descriptions ADDLW Add Literal and W BCF Bit Clear f Syntax: [ label ] ADDLW Syntax: [ label ] BCF Operands: 0 k 255 Operands: 0 f 127 0b7 Operation: (W) + k (W) Status Affected: C, DC, Z Operation: 0 (f<b>) Description: The contents of the W register are added to the eight-bit literal 'k' and the result is placed in the W register. Status Affected: None Description: Bit 'b' in register 'f' is cleared. ADDWF Add W and f BSF Bit Set f Syntax: [ label ] ADDWF Syntax: [ label ] BSF Operands: 0 f 127 d Operands: 0 f 127 0b7 Operation: (W) + (f) (destination) Operation: 1 (f<b>) Status Affected: C, DC, Z Status Affected: None Description: Add the contents of the W register with register 'f'. If 'd' is 0, the result is stored in the W register. If 'd' is 1, the result is stored back in register 'f'. Description: Bit 'b' in register 'f' is set. ANDLW AND Literal with W BTFSS Bit Test f, Skip if Set Syntax: [ label ] ANDLW Syntax: [ label ] BTFSS f,b Operands: 0 k 255 Operands: Operation: (W) .AND. (k) (W) 0 f 127 0b<7 Status Affected: Z Operation: skip if (f<b>) = 1 Description: The contents of W register are AND'ed with the eight-bit literal 'k'. The result is placed in the W register. Status Affected: None Description: If bit 'b' in register 'f' is '0', the next instruction is executed. If bit 'b' is '1', then the next instruction is discarded and a NOP is executed instead, making this a 2 TCY instruction. BTFSC Bit Test, Skip if Clear Syntax: [ label ] BTFSC f,b k f,d k f,b f,b ANDWF AND W with f Syntax: [ label ] ANDWF Operands: 0 f 127 d Operands: 0 f 127 0b7 Operation: (W) .AND. (f) (destination) Operation: skip if (f<b>) = 0 Status Affected: Z Status Affected: None Description: AND the W register with register 'f'. If 'd' is 0, the result is stored in the W register. If 'd' is 1, the result is stored back in register 'f'. Description: If bit 'b' in register 'f' is '1', the next instruction is executed. If bit 'b', in register 'f', is '0', the next instruction is discarded, and a NOP is executed instead, making this a 2 TCY instruction. 2000-2013 Microchip Technology Inc. f,d DS30569C-page 105 PIC16F870/871 CALL Call Subroutine CLRWDT Clear Watchdog Timer Syntax: [ label ] CALL k Syntax: [ label ] CLRWDT Operands: 0 k 2047 Operands: None Operation: (PC)+ 1 TOS, k PC<10:0>, (PCLATH<4:3>) PC<12:11> Operation: Status Affected: None 00h WDT 0 WDT prescaler, 1 TO 1 PD Description: Call Subroutine. First, return address (PC+1) is pushed onto the stack. The eleven-bit immediate address is loaded into PC bits <10:0>. The upper bits of the PC are loaded from PCLATH. CALL is a two-cycle instruction. Status Affected: TO, PD Description: CLRWDT instruction resets the Watchdog Timer. It also resets the prescaler of the WDT. Status bits TO and PD are set. Clear f COMF Complement f CLRF Syntax: [ label ] CLRF Syntax: [ label ] COMF Operands: 0 f 127 Operands: Operation: 00h (f) 1Z 0 f 127 d [0,1] Operation: (f) (destination) Status Affected: Z Status Affected: Z Description: The contents of register 'f' are cleared and the Z bit is set. Description: The contents of register 'f' are complemented. If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in register 'f'. CLRW Clear W DECF Decrement f Syntax: [ label ] CLRW Syntax: [ label ] DECF f,d Operands: None Operands: Operation: 00h (W) 1Z 0 f 127 d [0,1] Operation: (f) - 1 (destination) Status Affected: Z Status Affected: Z Description: W register is cleared. Zero bit (Z) is set. Description: Decrement register 'f'. If 'd' is 0, the result is stored in the W register. If 'd' is 1, the result is stored back in register 'f'. DS30569C-page 106 f f,d 2000-2013 Microchip Technology Inc. PIC16F870/871 DECFSZ Decrement f, Skip if 0 INCFSZ Increment f, Skip if 0 Syntax: [ label ] DECFSZ f,d Syntax: [ label ] Operands: 0 f 127 d [0,1] Operands: 0 f 127 d [0,1] Operation: (f) - 1 (destination); skip if result = 0 Operation: (f) + 1 (destination), skip if result = 0 Status Affected: None Status Affected: None Description: The contents of register 'f' are decremented. If 'd' is 0, the result is placed in the W register. If 'd' is 1, the result is placed back in register 'f'. If the result is 1, the next instruction is executed. If the result is 0, then a NOP is executed instead making it a 2 TCY instruction. Description: The contents of register 'f' are incremented. If 'd' is 0, the result is placed in the W register. If 'd' is 1, the result is placed back in register 'f'. If the result is 1, the next instruction is executed. If the result is 0, a NOP is executed instead, making it a 2 TCY instruction. GOTO Unconditional Branch IORLW Inclusive OR Literal with W Syntax: [ label ] Syntax: [ label ] Operands: 0 k 2047 Operands: 0 k 255 Operation: k PC<10:0> PCLATH<4:3> PC<12:11> Operation: (W) .OR. k (W) Status Affected: Z Status Affected: None Description: Description: GOTO is an unconditional branch. The eleven-bit immediate value is loaded into PC bits <10:0>. The upper bits of PC are loaded from PCLATH<4:3>. GOTO is a two-cycle instruction. The contents of the W register are OR'ed with the eight bit literal 'k'. The result is placed in the W register. INCF Increment f IORWF Inclusive OR W with f Syntax: [ label ] Syntax: [ label ] Operands: 0 f 127 d [0,1] Operands: 0 f 127 d [0,1] Operation: (f) + 1 (destination) Operation: (W) .OR. (f) (destination) Status Affected: Z Status Affected: Z Description: The contents of register 'f' are incremented. If 'd' is 0, the result is placed in the W register. If 'd' is 1, the result is placed back in register 'f'. Description: Inclusive OR the W register with register 'f'. If 'd' is 0 the result is placed in the W register. If 'd' is 1 the result is placed back in register 'f'. GOTO k INCF f,d 2000-2013 Microchip Technology Inc. INCFSZ f,d IORLW k IORWF f,d DS30569C-page 107 PIC16F870/871 MOVF Move f Syntax: [ label ] Operands: 0 f 127 d [0,1] Operation: No operation Operation: (f) (destination) Status Affected: None Status Affected: Z Description: No operation. Description: The contents of register f are moved to a destination dependant upon the status of d. If d = 0, destination is W register. If d = 1, the destination is file register f itself. d = 1 is useful to test a file register, since status flag Z is affected. MOVLW Move Literal to W RETFIE Return from Interrupt Syntax: [ label ] Syntax: [ label ] Operands: 0 k 255 Operands: None Operation: k (W) Operation: TOS PC, 1 GIE MOVF f,d MOVLW k NOP No Operation Syntax: [ label ] Operands: None NOP RETFIE Status Affected: None Description: The eight-bit literal 'k' is loaded into W register. The don't cares will assemble as 0's. Status Affected: None MOVWF Move W to f RETLW Return with Literal in W Syntax: [ label ] Syntax: [ label ] Operands: 0 f 127 Operands: 0 k 255 Operation: (W) (f) Operation: Status Affected: None k (W); TOS PC Description: Move data from W register to register 'f'. Status Affected: None Description: The W register is loaded with the eight-bit literal 'k'. The program counter is loaded from the top of the stack (the return address). This is a two-cycle instruction. DS30569C-page 108 MOVWF f RETLW k 2000-2013 Microchip Technology Inc. PIC16F870/871 RLF Rotate Left f through Carry SLEEP Syntax: [ label ] RLF Syntax: [ label ] SLEEP Operands: 0 f 127 d [0,1] Operands: None Operation: Operation: See description below Status Affected: C Description: The contents of register 'f' are rotated one bit to the left through the Carry Flag. If 'd' is 0, the result is placed in the W register. If 'd' is 1, the result is stored back in register 'f'. 00h WDT, 0 WDT prescaler, 1 TO, 0 PD C f,d Status Affected: TO, PD Description: The power-down status bit, PD is cleared. Time-out status bit, TO is set. Watchdog Timer and its prescaler are cleared. The processor is put into SLEEP mode with the oscillator stopped. Register f RETURN Return from Subroutine SUBLW Subtract W from Literal Syntax: [ label ] Syntax: [ label ] SUBLW k Operands: None Operands: 0 k 255 Operation: TOS PC Operation: k - (W) W) Status Affected: None Status Affected: C, DC, Z Description: Return from subroutine. The stack is POPed and the top of the stack (TOS) is loaded into the program counter. This is a two-cycle instruction. Description: The W register is subtracted (2's complement method) from the eight-bit literal 'k'. The result is placed in the W register. RRF Rotate Right f through Carry SUBWF Subtract W from f Syntax: [ label ] Syntax: [ label ] SUBWF f,d Operands: 0 f 127 d [0,1] Operands: 0 f 127 d [0,1] Operation: See description below Operation: (f) - (W) destination) Status Affected: C The contents of register 'f' are rotated one bit to the right through the Carry Flag. If 'd' is 0, the result is placed in the W register. If 'd' is 1, the result is placed back in register 'f'. Status Affected: C, DC, Z Description: Description: Subtract (2's complement method) W register from register 'f'. If 'd' is 0, the result is stored in the W register. If 'd' is 1, the result is stored back in register 'f'. RETURN RRF f,d C 2000-2013 Microchip Technology Inc. Register f DS30569C-page 109 PIC16F870/871 SWAPF Swap Nibbles in f XORWF Exclusive OR W with f Syntax: [ label ] SWAPF f,d Syntax: [ label ] XORWF Operands: 0 f 127 d [0,1] Operands: 0 f 127 d [0,1] Operation: (f<3:0>) (destination<7:4>), (f<7:4>) (destination<3:0>) Operation: (W) .XOR. (f) destination) Status Affected: Z Status Affected: None Description: Description: The upper and lower nibbles of register 'f' are exchanged. If 'd' is 0, the result is placed in the W register. If 'd' is 1, the result is placed in register 'f'. Exclusive OR the contents of the W register with register 'f'. If 'd' is 0, the result is stored in the W register. If 'd' is 1, the result is stored back in register 'f'. XORLW Exclusive OR Literal with W Syntax: [ label ] XORLW k Operands: 0 k 255 Operation: (W) .XOR. k W) Status Affected: Z Description: The contents of the W register are XOR'ed with the eight-bit literal 'k'. The result is placed in the W register. DS30569C-page 110 f,d 2000-2013 Microchip Technology Inc. PIC16F870/871 13.0 DEVELOPMENT SUPPORT The PIC(R) microcontrollers are supported with a full range of hardware and software development tools: * Integrated Development Environment - MPLAB(R) IDE Software * Assemblers/Compilers/Linkers - MPASMTM Assembler - MPLAB C17 and MPLAB C18 C Compilers - MPLINKTM Object Linker/ MPLIBTM Object Librarian - MPLAB C30 C Compiler - MPLAB ASM30 Assembler/Linker/Library * Simulators - MPLAB SIM Software Simulator - MPLAB dsPIC30 Software Simulator * Emulators - MPLAB ICE 2000 In-Circuit Emulator - MPLAB ICE 4000 In-Circuit Emulator * In-Circuit Debugger - MPLAB ICD 2 * Device Programmers - PRO MATE(R) II Universal Device Programmer - PICSTART(R) Plus Development Programmer * Low Cost Demonstration Boards - PICDEMTM 1 Demonstration Board - PICDEM.netTM Demonstration Board - PICDEM 2 Plus Demonstration Board - PICDEM 3 Demonstration Board - PICDEM 4 Demonstration Board - PICDEM 17 Demonstration Board - PICDEM 18R Demonstration Board - PICDEM LIN Demonstration Board - PICDEM USB Demonstration Board * Evaluation Kits - KEELOQ(R) - PICDEM MSC - microID(R) - CAN - PowerSmart(R) - Analog 13.1 MPLAB Integrated Development Environment Software The MPLAB IDE software brings an ease of software development previously unseen in the 8/16-bit microcontroller market. The MPLAB IDE is a Windows(R) based application that contains: * An interface to debugging tools - simulator - programmer (sold separately) - emulator (sold separately) - in-circuit debugger (sold separately) * A full-featured editor with color coded context * A multiple project manager * Customizable data windows with direct edit of contents * High level source code debugging * Mouse over variable inspection * Extensive on-line help The MPLAB IDE allows you to: * Edit your source files (either assembly or C) * One touch assemble (or compile) and download to PIC MCU emulator and simulator tools (automatically updates all project information) * Debug using: - source files (assembly or C) - absolute listing file (mixed assembly and C) - machine code MPLAB IDE supports multiple debugging tools in a single development paradigm, from the cost effective simulators, through low cost in-circuit debuggers, to full-featured emulators. This eliminates the learning curve when upgrading to tools with increasing flexibility and power. 13.2 MPASM Assembler The MPASM assembler is a full-featured, universal macro assembler for all PIC MCUs. The MPASM assembler generates relocatable object files for the MPLINK object linker, Intel(R) standard HEX files, MAP files to detail memory usage and symbol reference, absolute LST files that contain source lines and generated machine code and COFF files for debugging. The MPASM assembler features include: * Integration into MPLAB IDE projects * User defined macros to streamline assembly code * Conditional assembly for multi-purpose source files * Directives that allow complete control over the assembly process 2000-2013 Microchip Technology Inc. DS30569C-page 111 PIC16F870/871 13.3 MPLAB C17 and MPLAB C18 C Compilers The MPLAB C17 and MPLAB C18 Code Development Systems are complete ANSI C compilers for Microchip's PIC17CXXX and PIC18CXXX family of microcontrollers. These compilers provide powerful integration capabilities, superior code optimization and ease of use not found with other compilers. For easy source level debugging, the compilers provide symbol information that is optimized to the MPLAB IDE debugger. 13.4 MPLINK Object Linker/ MPLIB Object Librarian The MPLINK object linker combines relocatable objects created by the MPASM assembler and the MPLAB C17 and MPLAB C18 C compilers. It can link relocatable objects from pre-compiled libraries, using directives from a linker script. The MPLIB object librarian manages the creation and modification of library files of pre-compiled code. When a routine from a library is called from a source file, only the modules that contain that routine will be linked in with the application. This allows large libraries to be used efficiently in many different applications. The object linker/library features include: * Efficient linking of single libraries instead of many smaller files * Enhanced code maintainability by grouping related modules together * Flexible creation of libraries with easy module listing, replacement, deletion and extraction 13.5 MPLAB C30 C Compiler The MPLAB C30 C compiler is a full-featured, ANSI compliant, optimizing compiler that translates standard ANSI C programs into dsPIC30F assembly language source. The compiler also supports many commandline options and language extensions to take full advantage of the dsPIC30F device hardware capabilities, and afford fine control of the compiler code generator. MPLAB C30 is distributed with a complete ANSI C standard library. All library functions have been validated and conform to the ANSI C library standard. The library includes functions for string manipulation, dynamic memory allocation, data conversion, timekeeping, and math functions (trigonometric, exponential and hyperbolic). The compiler provides symbolic information for high level source debugging with the MPLAB IDE. DS30569C-page 112 13.6 MPLAB ASM30 Assembler, Linker, and Librarian MPLAB ASM30 assembler produces relocatable machine code from symbolic assembly language for dsPIC30F devices. MPLAB C30 compiler uses the assembler to produce it's object file. The assembler generates relocatable object files that can then be archived or linked with other relocatable object files and archives to create an executable file. Notable features of the assembler include: * * * * * * Support for the entire dsPIC30F instruction set Support for fixed-point and floating-point data Command line interface Rich directive set Flexible macro language MPLAB IDE compatibility 13.7 MPLAB SIM Software Simulator The MPLAB SIM software simulator allows code development in a PC hosted environment by simulating the PIC series microcontrollers on an instruction level. On any given instruction, the data areas can be examined or modified and stimuli can be applied from a file, or user defined key press, to any pin. The execution can be performed in Single-Step, Execute Until Break, or Trace mode. The MPLAB SIM simulator fully supports symbolic debugging using the MPLAB C17 and MPLAB C18 C Compilers, as well as the MPASM assembler. The software simulator offers the flexibility to develop and debug code outside of the laboratory environment, making it an excellent, economical software development tool. 13.8 MPLAB SIM30 Software Simulator The MPLAB SIM30 software simulator allows code development in a PC hosted environment by simulating the dsPIC30F series microcontrollers on an instruction level. On any given instruction, the data areas can be examined or modified and stimuli can be applied from a file, or user defined key press, to any of the pins. The MPLAB SIM30 simulator fully supports symbolic debugging using the MPLAB C30 C Compiler and MPLAB ASM30 assembler. The simulator runs in either a Command Line mode for automated tasks, or from MPLAB IDE. This high speed simulator is designed to debug, analyze and optimize time intensive DSP routines. 2000-2013 Microchip Technology Inc. PIC16F870/871 13.9 MPLAB ICE 2000 High Performance Universal In-Circuit Emulator The MPLAB ICE 2000 universal in-circuit emulator is intended to provide the product development engineer with a complete microcontroller design tool set for PIC microcontrollers. Software control of the MPLAB ICE 2000 in-circuit emulator is advanced by the MPLAB Integrated Development Environment, which allows editing, building, downloading and source debugging from a single environment. The MPLAB ICE 2000 is a full-featured emulator system with enhanced trace, trigger and data monitoring features. Interchangeable processor modules allow the system to be easily reconfigured for emulation of different processors. The universal architecture of the MPLAB ICE in-circuit emulator allows expansion to support new PIC microcontrollers. The MPLAB ICE 2000 in-circuit emulator system has been designed as a real-time emulation system with advanced features that are typically found on more expensive development tools. The PC platform and Microsoft(R) Windows 32-bit operating system were chosen to best make these features available in a simple, unified application. 13.10 MPLAB ICE 4000 High Performance Universal In-Circuit Emulator The MPLAB ICE 4000 universal in-circuit emulator is intended to provide the product development engineer with a complete microcontroller design tool set for highend PIC microcontrollers. Software control of the MPLAB ICE in-circuit emulator is provided by the MPLAB Integrated Development Environment, which allows editing, building, downloading and source debugging from a single environment. The MPLAB ICD 4000 is a premium emulator system, providing the features of MPLAB ICE 2000, but with increased emulation memory and high speed performance for dsPIC30F and PIC18XXXX devices. Its advanced emulator features include complex triggering and timing, up to 2 Mb of emulation memory, and the ability to view variables in real-time. 13.11 MPLAB ICD 2 In-Circuit Debugger Microchip's In-Circuit Debugger, MPLAB ICD 2, is a powerful, low cost, run-time development tool, connecting to the host PC via an RS-232 or high speed USB interface. This tool is based on the FLASH PIC MCUs and can be used to develop for these and other PIC microcontrollers. The MPLAB ICD 2 utilizes the incircuit debugging capability built into the FLASH devices. This feature, along with Microchip's In-Circuit Serial ProgrammingTM (ICSPTM) protocol, offers cost effective in-circuit FLASH debugging from the graphical user interface of the MPLAB Integrated Development Environment. This enables a designer to develop and debug source code by setting breakpoints, singlestepping and watching variables, CPU status and peripheral registers. Running at full speed enables testing hardware and applications in real-time. MPLAB ICD 2 also serves as a development programmer for selected PIC devices. 13.12 PRO MATE II Universal Device Programmer The PRO MATE II is a universal, CE compliant device programmer with programmable voltage verification at VDDMIN and VDDMAX for maximum reliability. It features an LCD display for instructions and error messages and a modular detachable socket assembly to support various package types. In Stand-Alone mode, the PRO MATE II device programmer can read, verify, and program PIC devices without a PC connection. It can also set code protection in this mode. 13.13 PICSTART Plus Development Programmer The PICSTART Plus development programmer is an easy-to-use, low cost, prototype programmer. It connects to the PC via a COM (RS-232) port. MPLAB Integrated Development Environment software makes using the programmer simple and efficient. The PICSTART Plus development programmer supports most PIC devices up to 40 pins. Larger pin count devices, such as the PIC16C92X and PIC17C76X, may be supported with an adapter socket. The PICSTART Plus development programmer is CE compliant. The MPLAB ICE 4000 in-circuit emulator system has been designed as a real-time emulation system with advanced features that are typically found on more expensive development tools. The PC platform and Microsoft Windows 32-bit operating system were chosen to best make these features available in a simple, unified application. 2000-2013 Microchip Technology Inc. DS30569C-page 113 PIC16F870/871 13.14 PICDEM 1 PIC MCU Demonstration Board 13.17 PICDEM 3 PIC16C92X Demonstration Board The PICDEM 1 demonstration board demonstrates the capabilities of the PIC16C5X (PIC16C54 to PIC16C58A), PIC16C61, PIC16C62X, PIC16C71, PIC16C8X, PIC17C42, PIC17C43 and PIC17C44. All necessary hardware and software is included to run basic demo programs. The sample microcontrollers provided with the PICDEM 1 demonstration board can be programmed with a PRO MATE II device programmer, or a PICSTART Plus development programmer. The PICDEM 1 demonstration board can be connected to the MPLAB ICE in-circuit emulator for testing. A prototype area extends the circuitry for additional application components. Features include an RS-232 interface, a potentiometer for simulated analog input, push button switches and eight LEDs. The PICDEM 3 demonstration board supports the PIC16C923 and PIC16C924 in the PLCC package. All the necessary hardware and software is included to run the demonstration programs. 13.15 PICDEM.net Internet/Ethernet Demonstration Board The PICDEM.net demonstration board is an Internet/ Ethernet demonstration board using the PIC18F452 microcontroller and TCP/IP firmware. The board supports any 40-pin DIP device that conforms to the standard pinout used by the PIC16F877 or PIC18C452. This kit features a user friendly TCP/IP stack, web server with HTML, a 24L256 Serial EEPROM for Xmodem download to web pages into Serial EEPROM, ICSP/MPLAB ICD 2 interface connector, an Ethernet interface, RS-232 interface, and a 16 x 2 LCD display. Also included is the book and CD-ROM "TCP/IP Lean, Web Servers for Embedded Systems," by Jeremy Bentham 13.16 PICDEM 2 Plus Demonstration Board The PICDEM 2 Plus demonstration board supports many 18-, 28-, and 40-pin microcontrollers, including PIC16F87X and PIC18FXX2 devices. All the necessary hardware and software is included to run the demonstration programs. The sample microcontrollers provided with the PICDEM 2 demonstration board can be programmed with a PRO MATE II device programmer, PICSTART Plus development programmer, or MPLAB ICD 2 with a Universal Programmer Adapter. The MPLAB ICD 2 and MPLAB ICE in-circuit emulators may also be used with the PICDEM 2 demonstration board to test firmware. A prototype area extends the circuitry for additional application components. Some of the features include an RS-232 interface, a 2 x 16 LCD display, a piezo speaker, an on-board temperature sensor, four LEDs, and sample PIC18F452 and PIC16F877 FLASH microcontrollers. DS30569C-page 114 13.18 PICDEM 4 8/14/18-Pin Demonstration Board The PICDEM 4 can be used to demonstrate the capabilities of the 8-, 14-, and 18-pin PIC16XXXX and PIC18XXXX MCUs, including the PIC16F818/819, PIC16F87/88, PIC16F62XA and the PIC18F1320 family of microcontrollers. PICDEM 4 is intended to showcase the many features of these low pin count parts, including LIN and Motor Control using ECCP. Special provisions are made for low power operation with the supercapacitor circuit, and jumpers allow on-board hardware to be disabled to eliminate current draw in this mode. Included on the demo board are provisions for Crystal, RC or Canned Oscillator modes, a five volt regulator for use with a nine volt wall adapter or battery, DB-9 RS-232 interface, ICD connector for programming via ICSP and development with MPLAB ICD 2, 2x16 liquid crystal display, PCB footprints for H-Bridge motor driver, LIN transceiver and EEPROM. Also included are: header for expansion, eight LEDs, four potentiometers, three push buttons and a prototyping area. Included with the kit is a PIC16F627A and a PIC18F1320. Tutorial firmware is included along with the User's Guide. 13.19 PICDEM 17 Demonstration Board The PICDEM 17 demonstration board is an evaluation board that demonstrates the capabilities of several Microchip microcontrollers, including PIC17C752, PIC17C756A, PIC17C762 and PIC17C766. A programmed sample is included. The PRO MATE II device programmer, or the PICSTART Plus development programmer, can be used to reprogram the device for user tailored application development. The PICDEM 17 demonstration board supports program download and execution from external on-board FLASH memory. A generous prototype area is available for user hardware expansion. 2000-2013 Microchip Technology Inc. PIC16F870/871 13.20 PICDEM 18R PIC18C601/801 Demonstration Board 13.23 PICDEM USB PIC16C7X5 Demonstration Board The PICDEM 18R demonstration board serves to assist development of the PIC18C601/801 family of Microchip microcontrollers. It provides hardware implementation of both 8-bit Multiplexed/De-multiplexed and 16-bit Memory modes. The board includes 2 Mb external FLASH memory and 128 Kb SRAM memory, as well as serial EEPROM, allowing access to the wide range of memory types supported by the PIC18C601/801. The PICDEM USB Demonstration Board shows off the capabilities of the PIC16C745 and PIC16C765 USB microcontrollers. This board provides the basis for future USB products. 13.21 PICDEM LIN PIC16C43X Demonstration Board The powerful LIN hardware and software kit includes a series of boards and three PIC microcontrollers. The small footprint PIC16C432 and PIC16C433 are used as slaves in the LIN communication and feature onboard LIN transceivers. A PIC16F874 FLASH microcontroller serves as the master. All three microcontrollers are programmed with firmware to provide LIN bus communication. 13.22 PICkitTM 1 FLASH Starter Kit A complete "development system in a box", the PICkit FLASH Starter Kit includes a convenient multi-section board for programming, evaluation, and development of 8/14-pin FLASH PIC(R) microcontrollers. Powered via USB, the board operates under a simple Windows GUI. The PICkit 1 Starter Kit includes the user's guide (on CD ROM), PICkit 1 tutorial software and code for various applications. Also included are MPLAB(R) IDE (Integrated Development Environment) software, software and hardware "Tips 'n Tricks for 8-pin FLASH PIC(R) Microcontrollers" Handbook and a USB Interface Cable. Supports all current 8/14-pin FLASH PIC microcontrollers, as well as many future planned devices. 2000-2013 Microchip Technology Inc. 13.24 Evaluation and Programming Tools In addition to the PICDEM series of circuits, Microchip has a line of evaluation kits and demonstration software for these products. * KEELOQ evaluation and programming tools for Microchip's HCS Secure Data Products * CAN developers kit for automotive network applications * Analog design boards and filter design software * PowerSmart battery charging evaluation/ calibration kits * IrDA(R) development kit * microID development and rfLabTM development software * SEEVAL(R) designer kit for memory evaluation and endurance calculations * PICDEM MSC demo boards for Switching mode power supply, high power IR driver, delta sigma ADC, and flow rate sensor Check the Microchip web page and the latest Product Line Card for the complete list of demonstration and evaluation kits. DS30569C-page 115 PIC16F870/871 NOTES: DS30569C-page 116 2000-2013 Microchip Technology Inc. PIC16F870/871 14.0 ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings Ambient temperature under bias................................................................................................................ .-55 to +125C Storage temperature .............................................................................................................................. -65C to +150C Voltage on any pin with respect to VSS (except VDD, MCLR. and RA4) ......................................... -0.3V to (VDD + 0.3V) Voltage on VDD with respect to VSS ............................................................................................................ -0.3 to +7.5V Voltage on MCLR with respect to VSS (Note 2) ............................................................................................0 to +13.25V Voltage on RA4 with respect to Vss ..................................................................................................................0 to +8.5V Total power dissipation (Note 1) ...............................................................................................................................1.0W Maximum current out of VSS pin ...........................................................................................................................300 mA Maximum current into VDD pin ..............................................................................................................................250 mA Input clamp current, IIK (VI < 0 or VI > VDD) 20 mA Output clamp current, IOK (VO < 0 or VO > VDD) 20 mA Maximum output current sunk by any I/O pin..........................................................................................................25 mA Maximum output current sourced by any I/O pin ....................................................................................................25 mA Maximum current sunk byPORTA, PORTB, and PORTE (combined) (Note 3) ...................................................200 mA Maximum current sourced by PORTA, PORTB, and PORTE (combined) (Note 3)..............................................200 mA Maximum current sunk by PORTC and PORTD (combined) (Note 3) .................................................................200 mA Maximum current sourced by PORTC and PORTD (combined) (Note 3) ............................................................200 mA Note 1: Power dissipation is calculated as follows: Pdis = VDD x {IDD - IOH} + {(VDD - VOH) x IOH} + (VOl x IOL) 2: Voltage spikes below VSS at the MCLR pin, inducing currents greater than 80 mA, may cause latch-up. Thus, a series resistor of 50-100 should be used when applying a "low" level to the MCLR pin, rather than pulling this pin directly to VSS. 3: PORTD and PORTE are not implemented on the 28-pin devices. NOTICE: Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. 2000-2013 Microchip Technology Inc. DS30569C-page 117 PIC16F870/871 FIGURE 14-1: PIC16FXXX VOLTAGE-FREQUENCY GRAPH 6.0V 5.5V Voltage 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V 20 MHz Frequency FIGURE 14-2: PIC16LFXXX VOLTAGE-FREQUENCY GRAPH 6.0V 5.5V Voltage 5.0V 4.5V 4.0V 3.5V 3.0V Eq 2.5V 2.0V Eq 4 MHz ti ua on n tio ua 2 1 10 MHz 20 MHz Frequency Equation 1: FMAX = (6.0 MHz/V) (VDDAPPMIN - 2.0V) + 4 MHz; VDDAPPMIN = 2.0V - 3.0V Equation 2: FMAX = (10.0 MHz/V) (VDDAPPMIN - 3.0V) + 10 MHz; VDDAPPMIN = 3.0V - 4.0V Note 1: VDDAPPMIN is the minimum voltage of the PIC(R) device in the application. Note 2: FMAX has a maximum frequency of 10 MHz. DS30569C-page 118 2000-2013 Microchip Technology Inc. PIC16F870/871 14.1 DC Characteristics: PIC16F870/871 (Industrial, Extended) PIC16LF870/871 (Commercial, Industrial) PIC16LF870/871 (Commercial, Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for Industrial 0C TA +70C for Commercial PIC16F870/871 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for Industrial -40C TA +125C for Extended Param No. Sym VDD D001 D001 D001A Characteristic Min Typ Max Units Conditions Supply Voltage PIC16LF870/871 2.0 -- 5.5 V All configurations. See Figure 14-2 for details. PIC16F870/871 4.0 VBOR* -- -- 5.5 5.5 V V VBOR -- 5.5 V All configurations. BOR enabled, FMAX = 14 MHz (Note 7), -40C to +85C BOR enabled, FMAX = 10 MHz (Note 7), -40C to +125C D002* VDR RAM Data Retention Voltage(1) -- 1.5 -- V D003 VPOR VDD Start Voltage to ensure internal Power-on Reset signal -- Vss -- V D004* SVDD VDD Rise Rate to ensure internal Power-on Reset signal 0.05 -- -- D005 VBOR Brown-out Reset Voltage 3.7 4.0 4.35 See section on Power-on Reset for details V/ms See section on Power-on Reset for details V BOREN bit in configuration word enabled * These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: This is the limit to which VDD can be lowered without losing RAM data. 2: The supply current is mainly a function of the operating voltage and frequency. Other factors such as I/O pin loading and switching rate, oscillator type, internal code execution pattern and temperature also have an impact on the current consumption. The test conditions for all IDD measurements in active Operation mode are: OSC1 = external square wave, from rail to rail; all I/O pins tri-stated, pulled to VDD MCLR = VDD; WDT enabled/disabled as specified. 3: The power-down current in SLEEP mode does not depend on the oscillator type. Power-down current is measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD and VSS. 4: For RC osc configuration, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in k. 5: Timer1 oscillator (when enabled) adds approximately 20 A to the specification. This value is from characterization and is for design guidance only. This is not tested. 6: The current is the additional current consumed when this peripheral is enabled. This current should be added to the base IDD or IPD measurement. 7: When BOR is enabled, the device will operate correctly until the VBOR voltage trip point is reached. 2000-2013 Microchip Technology Inc. DS30569C-page 119 PIC16F870/871 14.1 DC Characteristics: PIC16F870/871 (Industrial, Extended) PIC16LF870/871 (Commercial, Industrial) (Continued) PIC16LF870/871 (Commercial, Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for Industrial 0C TA +70C for Commercial PIC16F870/871 (Industrial, Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for Industrial -40C TA +125C for Extended Param No. Sym IDD Characteristic PIC16LF870/871 D010A D010 PIC16F870/871 D013 IBOR Brown-out Reset Current(6) IPD Typ Max Units Conditions Supply Current(2,5) D010 D015* Min -- 0.6 2.0 mA XT, RC osc configuration FOSC = 4 MHz, VDD = 3.0V (Note 4) LP osc configuration FOSC = 32 kHz, VDD = 3.0V, WDT disabled -- 20 35 A -- 1.6 4 mA -- 7 15 mA -- 7 15 mA -- 85 200 A BOR enabled, VDD = 5.0V XT, RC osc configuration FOSC = 4 MHz, VDD = 5.5V (Note 4) HS osc configuration FOSC = 20 MHz, VDD = 5.5V, -40C to +85C HS osc configuration FOSC = 10 MHz, VDD = 5.5V, -40C to +125C Power-down Current(3,5) D020 D021 D021A PIC16LF870/871 -- -- -- 7.5 0.8 0.9 30 4.5 5 A A A VDD = 3.0V, WDT enabled, -40C to +85C VDD = 3.0V, WDT disabled, 0C to +70C VDD = 3.0V, WDT disabled, -40C to +85C D020 D20A D021 D021A D21B PIC16F870/871 -- -- -- -- -- 10.5 10.5 1.5 1.5 1.5 42 60 16 19 30 A A A A A VDD = 4.0V, WDT enabled, -40C to +85C VDD = 4.0V, WDT enabled, -40C to +125C VDD = 4.0V, WDT disabled, -0C to +70C VDD = 4.0V, WDT disabled, -40C to +85C VDD = 4.0V, WDT disabled, -40C to +125C -- 85 200 A BOR enabled, VDD = 5.0V D023* IBOR Brown-out Reset Current(6) * These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: This is the limit to which VDD can be lowered without losing RAM data. 2: The supply current is mainly a function of the operating voltage and frequency. Other factors such as I/O pin loading and switching rate, oscillator type, internal code execution pattern and temperature also have an impact on the current consumption. The test conditions for all IDD measurements in active Operation mode are: OSC1 = external square wave, from rail to rail; all I/O pins tri-stated, pulled to VDD MCLR = VDD; WDT enabled/disabled as specified. 3: The power-down current in SLEEP mode does not depend on the oscillator type. Power-down current is measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD and VSS. 4: For RC osc configuration, current through REXT is not included. The current through the resistor can be estimated by the formula Ir = VDD/2REXT (mA) with REXT in k. 5: Timer1 oscillator (when enabled) adds approximately 20 A to the specification. This value is from characterization and is for design guidance only. This is not tested. 6: The current is the additional current consumed when this peripheral is enabled. This current should be added to the base IDD or IPD measurement. 7: When BOR is enabled, the device will operate correctly until the VBOR voltage trip point is reached. DS30569C-page 120 2000-2013 Microchip Technology Inc. PIC16F870/871 14.2 DC Characteristics: PIC16F870/871 (Industrial) DC CHARACTERISTICS Param No. Sym VIL Characteristic Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for Industrial Operating voltage VDD range as described in DC spec Section 14.1 and Section 14.2. Min Typ Max Units Conditions with TTL buffer VSS -- 0.15 VDD V For entire VDD range VSS -- 0.8V V 4.5V VDD 5.5V with Schmitt Trigger buffer VSS -- 0.2 VDD V Input Low Voltage I/O ports: D030 D030A D031 D032 MCLR, OSC1 (in RC mode) VSS -- 0.2 VDD V D033 OSC1 (in XT, HS and LP) VSS -- 0.3 VDD V (Note 1) with Schmitt Trigger buffer VSS -- 0.3 VDD V For entire VDD range with SMBus -0.5 -- 0.6 V For VDD = 4.5 to 5.5V 2.0 -- VDD V 4.5V VDD 5.5V 0.25 VDD + -- VDD V For entire VDD range For entire VDD range Ports RC3 and RC4: D034 D034A VIH Input High Voltage I/O ports: D040 with TTL buffer D040A -- 0.8V 0.8 VDD -- VDD V D042 MCLR 0.8 VDD -- VDD V D042A OSC1 (XT, HS and LP) 0.7 VDD -- VDD V D043 OSC1 (in RC mode) 0.9 VDD -- VDD V 0.7 VDD -- VDD V For entire VDD range D041 with Schmitt Trigger buffer (Note 1) Ports RC3 and RC4: D044 with Schmitt Trigger buffer D044A D070 with SMBus IPURB PORTB Weak Pull-up Current IIL 1.4 -- 5.5 V for VDD = 4.5 to 5.5V 50 250 400 A VDD = 5V, VPIN = VSS Input Leakage Current (Notes 2, 3) D060 I/O ports -- -- 1 A Vss VPIN VDD, Pin at hi-impedance D061 MCLR, RA4/T0CKI -- -- 5 A Vss VPIN VDD D063 OSC1 -- -- 5 A Vss VPIN VDD, XT, HS and LP osc configuration * These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the PIC16F870/871 be driven with external clock in RC mode. 2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent normal operating conditions. Higher leakage current may be measured at different input voltages. 3: Negative current is defined as current sourced by the pin. 2000-2013 Microchip Technology Inc. DS30569C-page 121 PIC16F870/871 14.2 DC Characteristics: PIC16F870/871 (Industrial) (Continued) DC CHARACTERISTICS Param No. Sym VOL Characteristic Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for Industrial Operating voltage VDD range as described in DC spec Section 14.1 and Section 14.2. Min Typ Max Units Conditions Output Low Voltage D080 I/O ports -- -- 0.6 V IOL = 8.5 mA, VDD = 4.5V, -40C to +85C D083 OSC2/CLKO (RC osc config) -- -- 0.6 V IOL = 1.6 mA, VDD = 4.5V, -40C to +85C VOH Output High Voltage D090 I/O ports (Note 3) VDD - 0.7 -- -- V IOH = -3.0 mA, VDD = 4.5V, -40C to +85C D092 OSC2/CLKO (RC osc config) VDD - 0.7 -- -- V IOH = -1.3 mA, VDD = 4.5V, -40C to +85C -- -- 8.5 V RA4 pin -- -- 15 pF In XT, HS and LP modes when external clock is used to drive OSC1. -- -- 50 pF -- -- 400 pF D150* VOD Open Drain High Voltage Capacitive Loading Specs on Output Pins D100 COSC2 OSC2 pin D101 CIO D102 CB D120 ED Endurance 100K -- -- D121 VDRW VDD for read/write VMIN -- 5.5 V D122 TDEW Erase/write cycle time -- 4 8 ms E/W 25C at 5V All I/O pins and OSC2 (in RC mode) SCL, SDA in I2C mode Data EEPROM Memory E/W 25C at 5V Using EECON to read/write VMIN = min operating voltage Program FLASH Memory D130 EP Endurance 1000 -- -- D131 VPR VDD for read VMIN -- 5.5 V VMIN = min operating voltage VDD for erase/write VMIN -- 5.5 V Using EECON to read/write, VMIN = min operating voltage -- 4 8 ms D132a D133 TPEW Erase/Write cycle time * These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the PIC16F870/871 be driven with external clock in RC mode. 2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent normal operating conditions. Higher leakage current may be measured at different input voltages. 3: Negative current is defined as current sourced by the pin. DS30569C-page 122 2000-2013 Microchip Technology Inc. PIC16F870/871 14.3 DC Characteristics: PIC16F870/871 (Extended) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +125C Operating voltage VDD range as described in DC specification (Section ) DC CHARACTERISTICS Param No. Sym VIL Characteristic Min Typ Max Units Conditions with TTL buffer VSS -- 0.15 VDD V For entire VDD range VSS -- 0.8V V 4.5V VDD 5.5V with Schmitt Trigger buffer VSS -- 0.2 VDD V Input Low Voltage I/O ports: D030 D030A D031 D032 MCLR, OSC1 (in RC mode) VSS -- 0.2 VDD V D033 OSC1 (in XT, HS and LP) VSS -- 0.3 VDD V (Note 1) with Schmitt Trigger buffer VSS -- 0.3 VDD V For entire VDD range with SMBus -0.5 -- 0.6 V For VDD = 4.5 to 5.5V 2.0 -- VDD V 4.5V VDD 5.5V 0.25 VDD -- VDD V For entire VDD range 0.8 VDD -- VDD V For entire VDD range 0.8 VDD -- VDD V Ports RC3 and RC4: D034 D034A VIH Input High Voltage I/O ports: D040 with TTL buffer D040A -- + 0.8V D041 with Schmitt Trigger buffer D042 MCLR D042A OSC1 (XT, HS and LP) 0.7 VDD -- VDD V D043 OSC1 (in RC mode) 0.9 VDD -- VDD V 0.7 VDD -- VDD V For entire VDD range (Note 1) Ports RC3 and RC4: D044 with Schmitt Trigger buffer D044A with SMBus D070A IPURB PORTB Weak Pull-up Current IIL 1.4 -- 5.5 V For VDD = 4.5 to 5.5V 50 250 400 A VDD = 5V, VPIN = VSS Input Leakage Current(2,3) D060 I/O ports -- -- 1 A Vss VPIN VDD, Pin at hi-impedance D061 MCLR, RA4/T0CKI -- -- 5 A Vss VPIN VDD D063 OSC1 -- -- 5 A Vss VPIN VDD, XT, HS and LP osc configuration * These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the PIC16F87X be driven with external clock in RC mode. 2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent normal operating conditions. Higher leakage current may be measured at different input voltages. 3: Negative current is defined as current sourced by the pin. 2000-2013 Microchip Technology Inc. DS30569C-page 123 PIC16F870/871 14.3 DC Characteristics: PIC16F870/871 (Extended) (Continued) Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +125C Operating voltage VDD range as described in DC specification (Section ) DC CHARACTERISTICS Param No. Sym VOL Characteristic Min Typ Max Units Conditions Output Low Voltage D080A I/O ports -- -- 0.6 V IOL = 7.0 mA, VDD = 4.5V D083A OSC2/CLKO (RC osc config) -- -- 0.6 V IOL = 1.2 mA, VDD = 4.5V I/O ports(3) VDD - 0.7 -- -- V IOH = -2.5 mA, VDD = 4.5V OSC2/CLKO (RC osc config) VDD - 0.7 -- -- V IOH = -1.0 mA, VDD = 4.5V -- -- 8.5 V RA4 pin In XT, HS and LP modes when external clock is used to drive OSC1 VOH D090A D092A D150* VOD Output High Voltage Open Drain High Voltage Capacitive Loading Specs on Output Pins D100 COSC2 OSC2 pin -- -- 15 pF D101 CIO -- -- 50 pF D102 CB -- -- 400 pF All I/O pins and OSC2 (RC mode) SCL, SDA (I2C mode) Data EEPROM Memory D120 ED Endurance 100K -- -- E/W 25C at 5V D121 VDRW VDD for read/write VMIN -- 5.5 V D122 TDEW Erase/write cycle time -- 4 8 ms D130 EP Endurance 1000 -- -- E/W 25C at 5V D131 VPR VDD for read VMIN -- 5.5 V VMIN = min operating voltage VDD for erase/write VMIN -- 5.5 V Using EECON to read/write, VMIN = min. operating voltage -- 4 8 ms Using EECON to read/write, VMIN = min. operating voltage Program FLASH Memory D132A D133 TPEW Erase/Write cycle time * These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the PIC16F87X be driven with external clock in RC mode. 2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent normal operating conditions. Higher leakage current may be measured at different input voltages. 3: Negative current is defined as current sourced by the pin. DS30569C-page 124 2000-2013 Microchip Technology Inc. PIC16F870/871 14.4 Timing Parameter Symbology The timing parameter symbols have been created following one of the following formats: 1. TppS2ppS 3. TCC:ST (I2C specifications only) 2. TppS 4. Ts (I2C specifications only) T F Frequency Lowercase letters (pp) and their meanings: pp cc CCP1 ck CLKO cs CS di SDI do SDO dt Data in io I/O port mc MCLR Uppercase letters and their meanings: S F Fall H High I Invalid (Hi-impedance) L Low I2C only AA BUF output access Bus free TCC:ST (I2C specifications only) CC HD Hold ST DAT DATA input hold STA START condition 2000-2013 Microchip Technology Inc. T Time osc rd rw sc ss t0 t1 wr OSC1 RD RD or WR SCK SS T0CKI T1CKI WR P R V Z Period Rise Valid Hi-impedance High Low High Low SU Setup STO STOP condition DS30569C-page 125 PIC16F870/871 FIGURE 14-3: LOAD CONDITIONS Load condition 2 Load condition 1 VDD/2 RL CL Pin CL Pin VSS VSS RL = 464 CL = 50 pF 15 pF Note: FIGURE 14-4: for all pins except OSC2, but including PORTD and PORTE outputs as ports for OSC2 output PORTD and PORTE are not implemented on the PIC16F870. EXTERNAL CLOCK TIMING Q4 Q1 Q2 Q3 Q4 Q1 OSC1 1 3 3 4 4 2 CLKO DS30569C-page 126 2000-2013 Microchip Technology Inc. PIC16F870/871 TABLE 14-1: Param No. Sym FOSC EXTERNAL CLOCK TIMING REQUIREMENTS Characteristic External CLKI Frequency (Note 1) Oscillator Frequency (Note 1) 1 TOSC External CLKI Period (Note 1) Oscillator Period (Note 1) Min Typ Max Units Conditions DC -- 4 MHz XT and RC Osc mode DC -- 4 MHz HS Osc mode (-04) DC -- 20 MHz HS Osc mode (-20) DC -- 200 kHz DC -- 4 MHz RC Osc mode 0.1 -- 4 MHz XT Osc mode 4 5 -- -- 20 200 MHz HS Osc mode kHz LP Osc mode LP Osc mode 250 -- -- ns XT and RC Osc mode 250 -- -- ns HS Osc mode (-04) 50 -- -- ns HS Osc mode (-20) 5 -- -- s LP Osc mode 250 -- -- ns RC Osc mode 250 -- 10,000 ns XT Osc mode 250 -- 250 ns HS Osc mode (-04) 50 -- 250 ns HS Osc mode (-20) 5 -- -- s LP Osc mode 2 TCY Instruction Cycle Time (Note 1) 200 TCY DC ns TCY = 4/FOSC 3 TosL, TosH External Clock in (OSC1) High or Low Time 100 -- -- ns XT oscillator 2.5 -- -- s LP oscillator 15 -- -- ns HS oscillator TosR, TosF External Clock in (OSC1) Rise or Fall Time -- -- 25 ns XT oscillator 4 -- -- 50 ns LP oscillator -- -- 15 ns HS oscillator Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: Instruction cycle period (TCY) equals four times the input oscillator time base period. All specified values are based on characterization data for that particular oscillator type under standard operating conditions with the device executing code. Exceeding these specified limits may result in an unstable oscillator operation and/or higher than expected current consumption. All devices are tested to operate at "min." values with an external clock applied to the OSC1/CLKI pin. When an external clock input is used, the "Max." cycle time limit is "DC" (no clock) for all devices. 2000-2013 Microchip Technology Inc. DS30569C-page 127 PIC16F870/871 FIGURE 14-5: CLKO AND I/O TIMING Q1 Q4 Q2 Q3 OSC1 11 10 CLKO 13 19 14 12 18 16 I/O Pin (Input) 15 17 I/O Pin (Output) New Value Old Value 20, 21 Note: Refer to Figure 14-3 for load conditions. TABLE 14-2: Param No. CLKO AND I/O TIMING REQUIREMENTS Min Typ Max TosH2ckL OSC1 to CLKO -- 75 200 ns (Note 1) 11* TosH2ckH OSC1 to CLKO -- 75 200 ns (Note 1) 12* TckR CLKO rise time -- 35 100 ns (Note 1) 13* TckF CLKO fall time -- 35 100 ns (Note 1) 14* TckL2ioV CLKO to Port out valid -- -- 0.5 TCY + 20 ns (Note 1) 15* TioV2ckH Port in valid before CLKO TOSC + 200 -- -- ns (Note 1) 16* TckH2ioI 0 -- -- ns (Note 1) 17* TosH2ioV OSC1 (Q1 cycle) to Port out valid -- 100 255 ns 18* TosH2ioI Standard (F) 100 -- -- ns Extended (LF) 200 -- -- ns 19* TioV2osH Port input valid to OSC1(I/O in setup time) 0 -- -- ns 20* TIOR Standard (F) -- 10 40 ns Extended (LF) -- -- 145 ns Standard (F) -- 10 40 ns Extended (LF) -- -- 145 ns 10* 21* Sym TIOF Characteristic Port in hold after CLKO OSC1 (Q2 cycle) to Port input invalid (I/O in hold time) Port output rise time Port output fall time Units Conditions 22* TINP INT pin high or low time TCY -- -- ns 23* TRBP RB7:RB4 change INT high or low time TCY -- -- ns * These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. These parameters are asynchronous events not related to any internal clock edges. Note 1: Measurements are taken in RC mode where CLKO output is 4 x TOSC. DS30569C-page 128 2000-2013 Microchip Technology Inc. PIC16F870/871 FIGURE 14-6: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP TIMER TIMING VDD MCLR 30 Internal POR 33 PWRT Time-out 32 Osc Time-out Internal RESET Watchdog Timer Reset 31 34 34 I/O Pins Note: Refer to Figure 14-3 for load conditions. FIGURE 14-7: BROWN-OUT RESET TIMING VBOR VDD 35 TABLE 14-3: Param No. Sym RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER, AND BROWN-OUT RESET REQUIREMENTS Characteristic Min Typ Max Units Conditions 30 TmcL MCLR Pulse Width (low) 2 -- -- s VDD = 5V, -40C to +85C 31* TWDT Watchdog Timer Time-out Period (No Prescaler) 7 18 33 ms VDD = 5V, -40C to +85C 32 TOST Oscillation Start-up Timer Period -- 1024 TOSC -- -- TOSC = OSC1 period 33* TPWRT Power up Timer Period 28 72 132 ms VDD = 5V, -40C to +85C 34 TIOZ I/O Hi-impedance from MCLR Low or Watchdog Timer Reset -- -- 2.1 s TBOR Brown-out Reset pulse width 100 -- -- s 35 VDD VBOR (D005) * These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. 2000-2013 Microchip Technology Inc. DS30569C-page 129 PIC16F870/871 FIGURE 14-8: TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS RA4/T0CKI 41 40 42 RC0/T1OSO/T1CKI 46 45 47 48 TMR0 or TMR1 Note: Refer to Figure 14-3 for load conditions. TABLE 14-4: Param No. TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS Sym Characteristic 40* Tt0H T0CKI High Pulse Width 41* Tt0L T0CKI Low Pulse Width No Prescaler With Prescaler No Prescaler With Prescaler 42* Tt0P T0CKI Period No Prescaler With Prescaler 45* 46* Tt1H Tt1L T1CKI High Time T1CKI Low Time Synchronous, Prescaler = 1 Tt1P 48 Units 0.5 TCY + 20 -- -- ns -- -- ns -- -- ns 10 -- -- ns TCY + 40 -- -- ns -- -- ns N = prescale value (2, 4, ..., 256) Must also meet parameter 47 Greater of: 20 or TCY + 40 N -- ns -- -- ns 25 -- -- ns Asynchronous Standard(F) 30 -- -- ns Extended(LF) 50 -- -- ns 0.5 TCY + 20 -- -- ns Synchronous, Standard(F) Prescaler = 2,4,8 Extended(LF) 15 -- -- ns 25 -- -- ns Asynchronous 30 -- -- ns 50 -- -- ns -- -- ns Standard(F) T1CKI input period Synchronous Standard(F) Greater of: 30 or TCY + 40 N Extended(LF) Greater of: 50 or TCY + 40 N Must also meet parameter 42 Must also meet parameter 47 N = prescale value (1, 2, 4, 8) N = prescale value (1, 2, 4, 8) Standard(F) 60 -- -- ns Extended(LF) 100 -- -- ns DC -- 200 kHz 2 TOSC -- 7 TOSC -- Timer1 oscillator input frequency range (oscillator enabled by setting bit T1OSCEN) Must also meet parameter 42 10 -- Synchronous, Prescaler = 1 Conditions 0.5 TCY + 20 15 TCKEZtmr1 Delay from external clock edge to timer increment * Max 0.5 TCY + 20 Asynchronous Ft1 Typ Synchronous, Standard(F) Prescaler = 2,4,8 Extended(LF) Extended(LF) 47* Min These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. DS30569C-page 130 2000-2013 Microchip Technology Inc. PIC16F870/871 FIGURE 14-9: CAPTURE/COMPARE/PWM TIMINGS (CCP1) RC2/CCP1 (Capture Mode) 50 51 52 RC2/CCP1 (Compare or PWM Mode) 53 54 Note: Refer to Figure 14-3 for load conditions. TABLE 14-5: Param No. 50* 51* CAPTURE/COMPARE/PWM REQUIREMENTS (CCP1) Sym TccL TccH Characteristic * CCP1 input low time CCP1 input high time No Prescaler With Prescaler TccP CCP1 input period 53* TccR CCP1 output rise time 54* TccF CCP1 output fall time * Standard(F) Extended(LF) Typ Max Units 0.5 TCY + 20 -- -- ns 10 -- -- ns 20 -- -- ns 0.5 TCY + 20 -- -- ns Standard(F) 10 -- -- ns Extended(LF) 20 -- -- ns 3 TCY + 40 N -- -- ns Standard(F) -- 10 25 ns Extended(LF) -- 25 50 ns Standard(F) -- 10 25 ns Extended(LF) -- 25 45 ns No Prescaler With Prescaler 52* Min Conditions N = prescale value (1,4 or 16) These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. 2000-2013 Microchip Technology Inc. DS30569C-page 131 PIC16F870/871 FIGURE 14-10: PARALLEL SLAVE PORT TIMING (PIC16F871 ONLY) RE2/CS RE0/RD RE1/WR 65 RD7:RD0 62 64 63 Note: Refer to Figure 14-3 for load conditions. TABLE 14-6: Param No. PARALLEL SLAVE PORT REQUIREMENTS (PIC16F871 ONLY) Sym Characteristic Min Typ Max Units 62 TdtV2wrH Data in valid before WR or CS (setup time) 20 25 -- -- -- -- ns ns 63* TwrH2dtI WR or CS to data-in invalid (hold time) Standard(F) 20 -- -- ns 35 -- -- ns 64 TrdL2dtV RD and CS to data-out valid -- -- -- -- 80 90 ns ns 10 -- 30 ns Extended(LF) 65 TrdH2dtI * RD or CS to data-out invalid Conditions Extended range only Extended range only These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. DS30569C-page 132 2000-2013 Microchip Technology Inc. PIC16F870/871 FIGURE 14-11: USART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING RC6/TX/CK pin 121 121 RC7/RX/DT pin 120 122 Note: Refer to Figure 14-3 for load conditions. TABLE 14-7: Param No. 120 121 122 USART SYNCHRONOUS TRANSMISSION REQUIREMENTS Sym Characteristic TckH2dtV SYNC XMIT (MASTER & SLAVE) Clock high to data out valid Tckrf Tdtrf Min Typ Max Units Conditions Standard(F) -- -- 80 ns Extended(LF) -- -- 100 ns Clock out rise time and fall time (Master mode) Standard(F) -- -- 45 ns Extended(LF) -- -- 50 ns Data out rise time and fall time Standard(F) -- -- 45 ns Extended(LF) -- -- 50 ns Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. FIGURE 14-12: USART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING RC6/TX/CK pin RC7/RX/DT pin 125 126 Note: Refer to Figure 14-3 for load conditions. TABLE 14-8: Param No. USART SYNCHRONOUS RECEIVE REQUIREMENTS Sym 125 TdtV2ckL 126 TckL2dtl Characteristic Min Typ Max Units SYNC RCV (MASTER & SLAVE) Data setup before CK (DT setup time) 15 -- -- ns Data hold after CK (DT hold time) 15 -- -- ns Conditions Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. 2000-2013 Microchip Technology Inc. DS30569C-page 133 PIC16F870/871 TABLE 14-9: PIC16F870/871 (INDUSTRIAL) PIC16LF870/871 (INDUSTRIAL) Param Sym No. Characteristic Min Typ Max Units Conditions A01 NR Resolution -- -- 10-bits bit VREF = VDD = 5.12V, VSS VAIN VREF A03 EIL Integral linearity error -- -- <1 LSb VREF = VDD = 5.12V, VSS VAIN VREF A04 EDL Differential linearity error -- -- <1 LSb VREF = VDD = 5.12V, VSS VAIN VREF A06 EOFF Offset error -- -- <1 LSb VREF = VDD = 5.12V, VSS VAIN VREF A07 EGN Gain error -- -- <1 LSb VREF = VDD = 5.12V, VSS VAIN VREF A10 -- Monotonicity(3) -- guaranteed -- -- A20 VREF Reference voltage (VREF+ - VREF-) 2.0V -- VDD + 0.3 V A21 VREF+ Reference voltage High VDD - 2.5V VDD + 0.3V V Must meet spec. A20 A22 VREF- Reference voltage Low VSS - 0.3V VREF+ - 2.0V V Must meet spec. A20 A25 VAIN Analog input voltage A30 ZAIN Recommended impedance of analog voltage source A40 IAD A/D conversion current (VDD) A50 IREF * Note 1: 2: 3: VSS - 0.3 -- VREF + 0.3 V -- -- 10.0 k Standard(F) -- 220 -- A Extended(LF) -- 90 -- A 10 -- 1000 A -- -- 10 A VREF input current (Note 2) VSS VAIN VREF Average current consumption when A/D is on (Note 1). During VAIN acquisition. Based on differential of VHOLD to VAIN to charge CHOLD, see Section 10.1. During A/D Conversion cycle These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. When A/D is off, it will not consume any current other than minor leakage current. The power-down current spec includes any such leakage from the A/D module. VREF current is from RA3 pin or VDD pin, whichever is selected as reference input. The A/D conversion result never decreases with an increase in the input voltage, and has no missing codes. DS30569C-page 134 2000-2013 Microchip Technology Inc. PIC16F870/871 FIGURE 14-13: A/D CONVERSION TIMING 1 TCY BSF ADCON0, GO (TOSC/2)(1) 131 Q4 130 A/D CLK 132 9 A/D DATA 8 7 2 1 0 NEW_DATA OLD_DATA ADRES ADIF GO DONE SAMPLING STOPPED SAMPLE Note 1: If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts. This allows the SLEEP instruction to be executed. TABLE 14-10: A/D CONVERSION REQUIREMENTS Param No. 130 Sym TAD Characteristic A/D clock period Min Typ Max Units Standard(F) 1.6 -- -- s TOSC based, VREF 3.0V Extended(LF) 3.0 -- -- s TOSC based, VREF 2.0V Standard(F) 2.0 4.0 6.0 s A/D RC Mode Extended(LF) 3.0 6.0 9.0 s A/D RC Mode -- 12 TAD (Note 2) 40 -- s 10* -- -- s The minimum time is the amplifier settling time. This may be used if the "new" input voltage has not changed by more than 1 LSb (i.e., 20.0 mV @ 5.12V) from the last sampled voltage (as stated on CHOLD). -- TOSC/2 -- -- If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts. This allows the SLEEP instruction to be executed. 131 TCNV Conversion time (not including S/H time) (Note 1) 132 TACQ Acquisition time 134 TGO * Note 1: 2: Q4 to A/D clock start Conditions These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. This specification ensured by design. ADRES register may be read on the following TCY cycle. See Section 10.1 for min conditions. 2000-2013 Microchip Technology Inc. DS30569C-page 135 PIC16F870/871 NOTES: DS30569C-page 136 2000-2013 Microchip Technology Inc. PIC16F870/871 15.0 DC AND AC CHARACTERISTICS GRAPHS AND TABLES Note: The graphs and tables provided following this note are a statistical summary based on a limited number of samples and are provided for informational purposes only. The performance characteristics listed herein are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified operating range (e.g., outside specified power supply range) and therefore, outside the warranted range. "Typical" represents the mean of the distribution at 25C. "Maximum" or "minimum" represents (mean + 3) or (mean - 3) respectively, where is a standard deviation, over the whole temperature range. FIGURE 15-1: TYPICAL IDD vs. FOSC OVER VDD (HS MODE) 7 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 6 5 5.5V I DD (mA) 4 5.0V 4.5V 3 4.0V 2 3.5V 3.0V 1 2 .5 V 2 .0 V 0 4 6 8 10 12 14 16 18 20 F O S C (M H z ) FIGURE 15-2: MAXIMUM IDD vs. FOSC OVER VDD (HS MODE) 8 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 7 6 5.5V 5 I DD (mA) 5.0V 4 4.5V 4.0V 3 3.5V 2 3.0V 1 2.5V 2.0V 0 4 6 8 10 12 14 16 18 20 F O S C (M H z ) 2000-2013 Microchip Technology Inc. DS30569C-page 137 PIC16F870/871 FIGURE 15-3: TYPICAL IDD vs. FOSC OVER VDD (XT MODE) 1.6 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 1.4 5.5V 1.2 5.0V 1.0 I DD (mA) 4.5V 0.8 4.0V 3.5V 0.6 3.0V 0.4 2.5V 2.0V 0.2 0.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 3.5 4.0 F OSC (MHz) FIGURE 15-4: MAXIMUM IDD vs. FOSC OVER VDD (LP MODE) 2.0 1.8 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 1.6 5.5V 1.4 5.0V I DD (mA) 1.2 4.5V 1.0 4.0V 0.8 3.5V 0.6 3.0V 2.5V 0.4 2.0V 0.2 0.0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 F OSC (MHz) DS30569C-page 138 2000-2013 Microchip Technology Inc. PIC16F870/871 FIGURE 15-5: TYPICAL IDD vs. FOSC OVER VDD (LP MODE) 90 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 80 5.5V 70 5.0V 60 IDD (uA) 4.5V 50 4.0V 3.5V 40 3.0V 30 2.5V 20 2.0V 10 0 20 30 40 50 60 70 80 90 100 F OS C (kH z ) FIGURE 15-6: MAXIMUM IDD vs. FOSC OVER VDD (XT MODE) 120 110 5.5V Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 100 5.0V 90 80 4.5V IDD (uA) 70 4.0V 60 3.5V 50 3.0V 40 2.5V 30 2.0V 20 10 0 20 30 40 50 60 70 80 90 100 F OSC (kH z ) 2000-2013 Microchip Technology Inc. DS30569C-page 139 PIC16F870/871 FIGURE 15-7: AVERAGE FOSC vs. VDD FOR VARIOUS VALUES OF R (RC MODE, C = 20 pF, 25C) 4.0 3.3k 3.5 3.0 5.1k Freq (MHz) 2.5 2.0 10k 1.5 1.0 0.5 100k 0.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 V DD (V) FIGURE 15-8: AVERAGE FOSC vs. VDD FOR VARIOUS VALUES OF R (RC MODE, C = 100 pF, 25C) 2.0 1.8 1.6 3.3 k Freq (MHz) 1.4 1.2 5.1 k 1.0 0.8 0.6 10 k 0.4 0.2 100 k 0.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 V D D (V ) DS30569C-page 140 2000-2013 Microchip Technology Inc. PIC16F870/871 FIGURE 15-9: AVERAGE FOSC vs. VDD FOR VARIOUS VALUES OF R (RC MODE, C = 300 pF, 25C) 1.0 0.9 0.8 3.3 k Freq (MHz) 0.7 0.6 5.1 k 0.5 0.4 0.3 10 k 0.2 0.1 100 k 0.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 5.0 5.5 V D D (V) FIGURE 15-10: IPD vs. VDD (SLEEP MODE, ALL PERIPHERALS DISABLED) 100.00 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) Max (125C) 10.00 I PD ( A) Max (85C) 1.00 0.10 Typ (25C) 0.01 2.0 2.5 3.0 3.5 4.0 4.5 VDD (V) 2000-2013 Microchip Technology Inc. DS30569C-page 141 PIC16F870/871 FIGURE 15-11: IBOR vs. VDD OVER TEMPERATURE 1.2 Note: 1.0 Device current in RESET depends on Oscillator mode, frequency and circuit. Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) Max RESET 0.6 I (mA) 0.8 Indeterminate State Typ RESET (25C) 0.4 Device in SLEEP Device in RESET 0.2 Max SLEEP Typ SLEEP (25C) 0.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 V D D (V) FIGURE 15-12: TYPICAL AND MAXIMUMITMR1 vs. VDD OVER TEMPERATURE (-10C TO 70C, TIMER1 WITH OSCILLATOR, XTAL=32 kHZ, C1 AND C2=50 pF) 90 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 80 70 ITMR1 (uA) 60 50 40 Max 30 Ty p (25C) 20 10 0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 V DD (V ) DS30569C-page 142 2000-2013 Microchip Technology Inc. PIC16F870/871 FIGURE 15-13: TYPICAL AND MAXIMUM IWDT vs. VDD OVER TEMPERATURE 14 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 12 10 I WDT (uA) Max (85C) 8 Typ (25C) 6 4 2 0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 V DD (V) FIGURE 15-14: TYPICAL, MINIMUM AND MAXIMUM WDT PERIOD vs. VDD (-40C TO 125C) 60 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 50 WDT Period (ms) 40 Max (125C) 30 20 Typ (25C) Min (-40C) 10 0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 V DD (V) 2000-2013 Microchip Technology Inc. DS30569C-page 143 PIC16F870/871 FIGURE 15-15: AVERAGE WDT PERIOD vs. VDD OVER TEMPERATURE (-40C TO 125C) 50 45 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 40 125C 35 WDT Period (ms) 85C 30 25 25C 20 -40C 15 10 5 0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 V DD (V) FIGURE 15-16: TYPICAL, MINIMUM AND MAXIMUM VOH vs. IOH (VDD = 5V, -40C TO 125C) 5.0 Max (-40C) 4.5 Typ (25C) VOH (V) 4.0 3.5 Min (125C) 3.0 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 2.5 2.0 0 5 10 15 20 25 I OH (-mA) DS30569C-page 144 2000-2013 Microchip Technology Inc. PIC16F870/871 FIGURE 15-17: TYPICAL, MINIMUM AND MAXIMUM VOH vs. IOH (VDD = 3V, -40C TO 125C) 3.0 Max (-40C) Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 2.5 Typ (25C) VOH (V) 2.0 1.5 Min (125C) 1.0 0.5 0.0 0 5 10 15 20 25 I OH (-mA) FIGURE 15-18: TYPICAL, MINIMUM AND MAXIMUM VOL vs. IOL (VDD = 5V, -40C TO 125C) 2.0 1.8 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 1.6 1.4 VOL (V) 1.2 1.0 Max (125C) 0.8 0.6 Typ (25C) 0.4 Min (-40C) 0.2 0.0 0 5 10 15 20 25 I OL (-mA) 2000-2013 Microchip Technology Inc. DS30569C-page 145 PIC16F870/871 FIGURE 15-19: TYPICAL, MINIMUM AND MAXIMUM VOL vs. IOL (VDD = 3V, -40C TO 125C) 3.0 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 2.5 VOL (V) 2.0 1.5 Max (125C) 1.0 Typ (25C) 0.5 Min (-40C) 0.0 0 5 10 15 20 25 I OL (-mA) FIGURE 15-20: MINIMUM AND MAXIMUM VIN vs. VDD, (TTL INPUT, -40C TO 125C) 1.8 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 1.6 Max (-40C) 1.4 1.2 VIN (V) Min (125C) 1.0 0.8 0.6 0.4 0.2 0.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 V DD (V) DS30569C-page 146 2000-2013 Microchip Technology Inc. PIC16F870/871 FIGURE 15-21: MINIMUM AND MAXIMUM VIN vs. VDD (ST INPUT, -40C TO 125C) 4.5 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 4.0 3.5 Max High (125C) 3.0 Min High (-40C) VIN (V) 2.5 2.0 Max Low (125C) 1.5 Min Low (-40C) 1.0 0.5 0.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 V DD (V) FIGURE 15-22: MINIMUM AND MAXIMUM VIN vs. VDD (I2C INPUT, -40C TO 125C) 3.5 Typical: statistical mean @ 25C Maximum: mean + 3 (-40C to 125C) Minimum: mean - 3 (-40C to 125C) 3.0 Max High (125C) 2.5 Min High (-40C) Max Low (125C) V IN (V) 2.0 Min Low (25C) 1.5 1.0 0.5 0.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 V DD (V) 2000-2013 Microchip Technology Inc. DS30569C-page 147 PIC16F870/871 NOTES: DS30569C-page 148 2000-2013 Microchip Technology Inc. PIC16F870/871 16.0 PACKAGING INFORMATION 16.1 Package Marking Information 28-Lead PDIP (Skinny DIP) Example XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX YYWWNNN 28-Lead SOIC 0317017 Example XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX YYWWNNN 28-Lead SSOP PIC16F870-I/SO 0310017 Example XXXXXXXXXXXX XXXXXXXXXXXX YYWWNNN Legend: XX...X Y YY WW NNN e3 * Note: PIC16F870-I/SP PIC16F870-I/SS 0320017 Customer-specific information Year code (last digit of calendar year) Year code (last 2 digits of calendar year) Week code (week of January 1 is week `01') Alphanumeric traceability code Pb-free JEDEC designator for Matte Tin (Sn) This package is Pb-free. The Pb-free JEDEC designator ( e3 ) can be found on the outer packaging for this package. In the event the full Microchip part number cannot be marked on one line, it will be carried over to the next line, thus limiting the number of available characters for customer-specific information. 2000-2013 Microchip Technology Inc. DS30569C-page 149 PIC16F870/871 Package Marking Information (Cont'd) 40-Lead PDIP Example XXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXX YYWWNNN 44-Lead TQFP XXXXXXXXXX XXXXXXXXXX XXXXXXXXXX YYWWNNN 44-Lead PLCC XXXXXXXXXX XXXXXXXXXX XXXXXXXXXX YYWWNNN DS30569C-page 150 PIC16F871-I/P 0312017 Example PIC16F871 -I/PT 0320017 Example PIC16F871 -I/L 0320017 2000-2013 Microchip Technology Inc. PIC16F870/871 28-Lead Skinny Plastic Dual In-line (SP) - 300 mil (PDIP) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging E1 D 2 n 1 E A2 A L c B1 A1 eB Units Number of Pins Pitch p B Dimension Limits n p INCHES* MIN NOM MILLIMETERS MAX MIN NOM 28 MAX 28 .100 2.54 Top to Seating Plane A .140 .150 .160 3.56 3.81 4.06 Molded Package Thickness A2 .125 .130 .135 3.18 3.30 3.43 Base to Seating Plane A1 .015 8.26 0.38 Shoulder to Shoulder Width E .300 .310 .325 7.62 7.87 Molded Package Width E1 .275 .285 .295 6.99 7.24 7.49 Overall Length D 1.345 1.365 1.385 34.16 34.67 35.18 Tip to Seating Plane L c .125 .130 .135 3.18 3.30 3.43 Lead Thickness .008 .012 .015 0.20 0.29 0.38 Upper Lead Width B1 .040 .053 .065 1.02 1.33 1.65 Lower Lead Width B .016 .019 .022 0.41 0.48 0.56 eB .320 .350 .430 8.13 8.89 10.92 5 10 15 5 10 15 5 10 15 5 10 15 Overall Row Spacing Mold Draft Angle Top Mold Draft Angle Bottom * Controlling Parameter Significant Characteristic Notes: Dimension D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MO-095 Drawing No. C04-070 2000-2013 Microchip Technology Inc. DS30569C-page 151 PIC16F870/871 28-Lead Plastic Small Outline (SO) - Wide, 300 mil (SOIC) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging E E1 p D B 2 1 n h 45 c A2 A L Units Dimension Limits n p Number of Pins Pitch Overall Height Molded Package Thickness Standoff Overall Width Molded Package Width Overall Length Chamfer Distance Foot Length Foot Angle Top Lead Thickness Lead Width Mold Draft Angle Top Mold Draft Angle Bottom * Controlling Parameter Significant Characteristic A A2 A1 E E1 D h L c B A1 MIN .093 .088 .004 .394 .288 .695 .010 .016 0 .009 .014 0 0 INCHES* NOM 28 .050 .099 .091 .008 .407 .295 .704 .020 .033 4 .011 .017 12 12 MAX .104 .094 .012 .420 .299 .712 .029 .050 8 .013 .020 15 15 MILLIMETERS NOM 28 1.27 2.36 2.50 2.24 2.31 0.10 0.20 10.01 10.34 7.32 7.49 17.65 17.87 0.25 0.50 0.41 0.84 0 4 0.23 0.28 0.36 0.42 0 12 0 12 MIN MAX 2.64 2.39 0.30 10.67 7.59 18.08 0.74 1.27 8 0.33 0.51 15 15 Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MS-013 Drawing No. C04-052 DS30569C-page 152 2000-2013 Microchip Technology Inc. PIC16F870/871 28-Lead Plastic Shrink Small Outline (SS) - 209 mil, 5.30 mm (SSOP) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging E E1 p D B 2 1 n A c A2 A1 L Units Dimension Limits n p Number of Pins Pitch Overall Height Molded Package Thickness Standoff Overall Width Molded Package Width Overall Length Foot Length Lead Thickness Foot Angle Lead Width Mold Draft Angle Top Mold Draft Angle Bottom * Controlling Parameter Significant Characteristic A A2 A1 E E1 D L c B MIN .068 .064 .002 .299 .201 .396 .022 .004 0 .010 0 0 INCHES NOM 28 .026 .073 .068 .006 .309 .207 .402 .030 .007 4 .013 5 5 MAX .078 .072 .010 .319 .212 .407 .037 .010 8 .015 10 10 MILLIMETERS* NOM MAX 28 0.65 1.73 1.85 1.98 1.63 1.73 1.83 0.05 0.15 0.25 7.59 7.85 8.10 5.11 5.25 5.38 10.06 10.20 10.34 0.56 0.75 0.94 0.10 0.18 0.25 0.00 101.60 203.20 0.25 0.32 0.38 0 5 10 0 5 10 MIN Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MS-150 Drawing No. C04-073 2000-2013 Microchip Technology Inc. DS30569C-page 153 PIC16F870/871 40-Lead Plastic Dual In-line (P) - 600 mil (PDIP) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging E1 D 2 1 n E A2 A L c B1 A1 eB p B Units Dimension Limits n p MIN INCHES* NOM 40 .100 .175 .150 MAX MILLIMETERS NOM 40 2.54 4.06 4.45 3.56 3.81 0.38 15.11 15.24 13.46 13.84 51.94 52.26 3.05 3.30 0.20 0.29 0.76 1.27 0.36 0.46 15.75 16.51 5 10 5 10 MIN Number of Pins Pitch Top to Seating Plane A .160 .190 Molded Package Thickness A2 .140 .160 Base to Seating Plane A1 .015 Shoulder to Shoulder Width E .595 .600 .625 Molded Package Width E1 .530 .545 .560 Overall Length D 2.045 2.058 2.065 Tip to Seating Plane L .120 .130 .135 c Lead Thickness .008 .012 .015 Upper Lead Width B1 .030 .050 .070 Lower Lead Width B .014 .018 .022 eB Overall Row Spacing .620 .650 .680 Mold Draft Angle Top 5 10 15 Mold Draft Angle Bottom 5 10 15 * Controlling Parameter Significant Characteristic Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MO-011 Drawing No. C04-016 DS30569C-page 154 MAX 4.83 4.06 15.88 14.22 52.45 3.43 0.38 1.78 0.56 17.27 15 15 2000-2013 Microchip Technology Inc. PIC16F870/871 44-Lead Plastic Thin Quad Flatpack (PT) 10x10x1 mm Body, 1.0/0.10 mm Lead Form (TQFP) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging E E1 #leads=n1 p D1 D 2 1 B n CH x 45 A c L A1 A2 (F) Units Dimension Limits n p Number of Pins Pitch Pins per Side Overall Height Molded Package Thickness Standoff Foot Length Footprint (Reference) Foot Angle Overall Width Overall Length Molded Package Width Molded Package Length Lead Thickness Lead Width Pin 1 Corner Chamfer Mold Draft Angle Top Mold Draft Angle Bottom * Controlling Parameter Significant Characteristic n1 A A2 A1 L (F) E D E1 D1 c B CH MIN .039 .037 .002 .018 0 .463 .463 .390 .390 .004 .012 .025 5 5 INCHES NOM 44 .031 11 .043 .039 .004 .024 .039 3.5 .472 .472 .394 .394 .006 .015 .035 10 10 MAX .047 .041 .006 .030 7 .482 .482 .398 .398 .008 .017 .045 15 15 MILLIMETERS* NOM 44 0.80 11 1.00 1.10 0.95 1.00 0.05 0.10 0.45 0.60 1.00 0 3.5 11.75 12.00 11.75 12.00 9.90 10.00 9.90 10.00 0.09 0.15 0.30 0.38 0.64 0.89 5 10 5 10 MIN MAX 1.20 1.05 0.15 0.75 7 12.25 12.25 10.10 10.10 0.20 0.44 1.14 15 15 Notes: Dimensions D1 and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MS-026 Drawing No. C04-076 2000-2013 Microchip Technology Inc. DS30569C-page 155 PIC16F870/871 44-Lead Plastic Leaded Chip Carrier (L) - Square (PLCC) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging E E1 #leads=n1 D1 D n 1 2 CH2 x 45 CH1 x 45 A3 A2 35 A B1 B c E2 Units Dimension Limits n p A1 p D2 INCHES* MIN NOM 44 .050 11 .165 .173 .145 .153 .028 .020 .024 .029 .040 .045 .000 .005 .685 .690 .685 .690 .650 .653 .650 .653 .590 .620 .590 .620 .008 .011 .026 .029 .013 .020 0 5 0 5 MAX MILLIMETERS NOM 44 1.27 11 4.19 4.39 3.68 3.87 0.71 0.51 0.61 0.74 1.02 1.14 0.00 0.13 17.40 17.53 17.40 17.53 16.51 16.59 16.51 16.59 14.99 15.75 14.99 15.75 0.20 0.27 0.66 0.74 0.33 0.51 0 5 0 5 MIN Number of Pins Pitch Pins per Side n1 Overall Height A .180 .160 Molded Package Thickness A2 .035 Standoff A1 Side 1 Chamfer Height A3 .034 Corner Chamfer 1 CH1 .050 .010 Corner Chamfer (others) CH2 Overall Width E .695 Overall Length D .695 Molded Package Width .656 E1 Molded Package Length D1 .656 Footprint Width E2 .630 Footprint Length D2 .630 c Lead Thickness .013 Upper Lead Width .032 B1 B .021 Lower Lead Width Mold Draft Angle Top 10 Mold Draft Angle Bottom 10 * Controlling Parameter Significant Characteristic Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MO-047 Drawing No. C04-048 DS30569C-page 156 MAX 4.57 4.06 0.89 0.86 1.27 0.25 17.65 17.65 16.66 16.66 16.00 16.00 0.33 0.81 0.53 10 10 2000-2013 Microchip Technology Inc. PIC16F870/871 APPENDIX A: REVISION HISTORY APPENDIX B: Revision A (December 1999) DEVICE DIFFERENCES The differences between the devices listed in this data sheet are shown in Table B-1. Original data sheet for the PIC16F870/871 family. Revision B (April 2003) This revision includes the DC and AC Characteristics Graphs and Tables. The Electrical Specifications in Section 14.0 have been updated and there have been minor corrections to the data sheet text. Revision C (January 2013) Added a note to each package outline drawing. TABLE B-1: DEVICE DIFFERENCES Feature On-chip Program Memory (Kbytes) PIC16F870 PIC16F871 2K 2K Data Memory (bytes) 128 128 Boot Block (bytes) 2048 512 Timer1 Low Power Option I/O Ports A/D Channels External Memory Interface Package Types 2000-2013 Microchip Technology Inc. Yes No Ports A, B, C Ports A, B, C, D, E 5 8 No No 28-pin DIP, SOIC, SSOP 40-pin PDIP, 44-pin PLCC, TQFP DS30569C-page 157 PIC16F870/871 APPENDIX C: CONVERSION CONSIDERATIONS This appendix discusses the considerations for converting from previous versions of a device to the ones listed in this data sheet. Typically, these changes are due to the differences in the process technology used. An example of this type of conversion is from a PIC17C756 to a PIC18F8720. Not Applicable APPENDIX D: MIGRATION FROM MID-RANGE TO ENHANCED DEVICES A detailed discussion of the differences between the mid-range MCU devices (i.e., PIC16CXXX) and the enhanced devices (i.e., PIC18FXXX) is provided in AN716, "Migrating Designs from PIC16C74A/74B to PIC18C442." The changes discussed, while device specific, are generally applicable to all mid-range to enhanced device migrations. This Application Note is available as Literature Number DS00716. DS30569C-page 158 2000-2013 Microchip Technology Inc. PIC16F870/871 APPENDIX E: MIGRATION FROM HIGH-END TO ENHANCED DEVICES A detailed discussion of the migration pathway and differences between the high-end MCU devices (i.e., PIC17CXXX) and the enhanced devices (i.e., PIC18FXXXX) is provided in AN726, "PIC17CXXX to PIC18CXXX Migration." This Application Note is available as Literature Number DS00726. 2000-2013 Microchip Technology Inc. DS30569C-page 159 PIC16F870/871 NOTES: DS30569C-page 160 2000-2013 Microchip Technology Inc. PIC16F870/871 INDEX A A/D ...................................................................................... 79 Acquisition Requirements ........................................... 82 ADCON0 Register....................................................... 79 ADCON1 Register....................................................... 79 ADIF Bit....................................................................... 80 ADRESH Register....................................................... 79 ADRESL Register ....................................................... 79 Analog Port Pins ................................................... 41, 42 Associated Registers and Bits .................................... 85 Calculating Acquisition Time....................................... 82 Configuring Analog Port Pins...................................... 83 Configuring the Interrupt ............................................. 81 Configuring the Module............................................... 81 Conversion Clock........................................................ 83 Conversions ................................................................ 84 Delays ......................................................................... 82 Effects of a RESET ..................................................... 85 GO/DONE Bit.............................................................. 80 Internal Sampling Switch (Rss) Impedance ................ 82 Operation During SLEEP ............................................ 85 Result Registers.......................................................... 84 Source Impedance...................................................... 82 Time Delays ................................................................ 82 Absolute Maximum Ratings .............................................. 117 ADCON0 Register............................................................... 13 ADCON1 Register............................................................... 14 ADRESH Registers ............................................................. 13 ADRESL Register ............................................................... 14 Analog-to-Digital Converter. See A/D. Application Notes AN552 (Implementing Wake-up on Key Stroke) ......... 35 AN556 (Implementing a Table Read) ......................... 24 Assembler MPASM Assembler................................................... 111 Asynchronous Reception Associated Registers .................................................. 69 Asynchronous Reception (9-bit Mode) Associated Registers .................................................. 71 B Banking, Data Memory ....................................................... 11 Baud Rate Generator (BRG) Associated Registers .................................................. 63 Block Diagrams A/D .............................................................................. 81 Analog Input Model ..................................................... 82 Capture Mode Operation ............................................ 56 Compare Mode Operation .......................................... 57 Interrupt Logic ............................................................. 97 On-Chip RESET Circuit .............................................. 91 PIC16F870.................................................................... 5 PIC16F871.................................................................... 6 PORTC (Peripheral Output Override) ......................... 37 PORTD (In I/O Port Mode).......................................... 38 PORTD and PORTE (Parallel Slave Port) .................. 42 PORTE (In I/O Port Mode).......................................... 39 PWM Mode ................................................................. 58 RA3:RA0 and RA5 Pins .............................................. 33 RA4/T0CKI Pin............................................................ 33 RB3:RB0 Pins ............................................................. 35 RB7:RB4 Pins ............................................................. 35 Timer0/WDT Prescaler ............................................... 45 2000-2013 Microchip Technology Inc. Timer1 ........................................................................ 50 Timer2 ........................................................................ 53 USART Asynchronous Receive.................................. 68 USART Asynchronous Receive (9-bit Mode) ............. 70 USART Transmit ........................................................ 66 Watchdog Timer ......................................................... 99 BOR. See Brown-out Reset. BRGH Bit ............................................................................ 63 Brown-out Reset (BOR).................................... 87, 91, 92, 93 BOR Status (BOR Bit) ................................................ 23 C C Compilers MPLAB C17.............................................................. 112 MPLAB C18.............................................................. 112 MPLAB C30.............................................................. 112 Capture/Compare/PWM (CCP) .......................................... 55 Associated Registers Capture, Compare and Timer1........................... 59 PWM and Timer2................................................ 60 Capture Mode............................................................. 56 CCP1IF............................................................... 56 Prescaler ............................................................ 56 CCP Timer Resources................................................ 55 Compare Special Trigger Output of CCP1 ......................... 57 Compare Mode........................................................... 57 Software Interrupt Mode ..................................... 57 Special Event Trigger ......................................... 57 PWM Mode................................................................. 58 Duty Cycle .......................................................... 58 Example Frequencies/Resolutions (table).......... 59 PWM Period ....................................................... 58 Setup for PWM Operation .................................. 59 Special Event Trigger and A/D Conversions .............. 57 CCP. See Capture/Compare/PWM. CCP1CON Register............................................................ 13 CCP1M0 Bit ........................................................................ 55 CCP1M1 Bit ........................................................................ 55 CCP1M2 Bit ........................................................................ 55 CCP1M3 Bit ........................................................................ 55 CCP1X Bit .......................................................................... 55 CCP1Y Bit .......................................................................... 55 CCPR1H Register......................................................... 13, 55 CCPR1L Register ......................................................... 13, 55 Code Examples Changing Between Capture Prescalers ..................... 56 EEPROM Data Read.................................................. 29 EEPROM Data Write .................................................. 29 FLASH Program Read................................................ 30 FLASH Program Write................................................ 31 Indirect Addressing..................................................... 24 Initializing PORTA ...................................................... 33 Saving STATUS, W and PCLATH Registers in RAM................................................................ 98 Code Protected Operation Data EEPROM and FLASH Program Memory ........... 31 Code Protection .......................................................... 87, 101 Computed GOTO................................................................ 24 Configuration Bits ............................................................... 87 Configuration Word............................................................. 88 Conversion Considerations............................................... 158 DS30569C-page 161 PIC16F870/871 D Data EEPROM .................................................................... 27 Associated Registers .................................................. 32 Code Protection .......................................................... 31 Reading....................................................................... 29 Spurious Write Protection ........................................... 31 Write Verify ................................................................. 31 Writing to ..................................................................... 29 Data Memory....................................................................... 11 Bank Select (RP1:RP0 Bits) ....................................... 11 General Purpose Registers......................................... 11 Register File Map ........................................................ 12 Special Function Registers ......................................... 13 DC and AC Characteristics Graphs and Tables................ 137 DC Characteristics PIC16F870/871 (Extended) ...................................... 123 PIC16F870/871 (Industrial) ....................................... 121 PIC16F870/871 (Industrial, Extended) and PIC16LF870/871 (Commercial, Industrial)........ 119 Demonstration Boards PICDEM 1 ................................................................. 114 PICDEM 17 ............................................................... 114 PICDEM 18R PIC18C601/801 .................................. 115 PICDEM 2 Plus ......................................................... 114 PICDEM 3 PIC16C92X ............................................. 114 PICDEM 4 ................................................................. 114 PICDEM LIN PIC16C43X ......................................... 115 PICDEM USB PIC16C7X5........................................ 115 PICDEM.net Internet/Ethernet .................................. 114 Development Support ....................................................... 111 Device Differences ............................................................ 157 Device Overview ................................................................... 5 Direct Addressing................................................................ 25 E EEADR Register ................................................................. 15 EEADRH Register............................................................... 15 EECON1 Register ......................................................... 15, 27 EECON2 Register ......................................................... 15, 27 EEDATA Register ............................................................... 15 EEDATH Register ............................................................... 15 Electrical Characteristics................................................... 117 Errata .................................................................................... 4 Evaluation and Programming Tools .................................. 115 F Firmware Instructions........................................................ 103 FLASH Program Memory.................................................... 27 Associated Registers .................................................. 32 Code Protection .......................................................... 31 Configuration Bits and Read/Write State .................... 32 Reading....................................................................... 30 Spurious Write Protection ........................................... 31 Write Protection .......................................................... 32 Write Verify ................................................................. 31 Writing to ..................................................................... 30 FSR Register........................................................... 13, 14, 15 I Indirect Addressing ............................................................. 25 FSR Register ........................................................ 11, 24 INDF Register ............................................................. 24 Instruction Descriptions .................................................... 105 Instruction Format............................................................. 103 Instruction Set................................................................... 103 ADDLW..................................................................... 105 ADDWF..................................................................... 105 ANDLW..................................................................... 105 ANDWF..................................................................... 105 BCF .......................................................................... 105 BSF........................................................................... 105 BTFSC ...................................................................... 105 BTFSS ...................................................................... 105 CALL......................................................................... 106 CLRF ........................................................................ 106 CLRW ....................................................................... 106 CLRWDT .................................................................. 106 COMF ....................................................................... 106 DECF ........................................................................ 106 DECFSZ ................................................................... 107 GOTO ....................................................................... 107 INCF ......................................................................... 107 INCFSZ..................................................................... 107 IORLW ...................................................................... 107 IORWF...................................................................... 107 MOVF ....................................................................... 108 MOVLW .................................................................... 108 MOVWF .................................................................... 108 NOP .......................................................................... 108 RETFIE ..................................................................... 108 RETLW ..................................................................... 108 RETURN................................................................... 109 RLF ........................................................................... 109 RRF .......................................................................... 109 SLEEP ...................................................................... 109 SUBLW ..................................................................... 109 SUBWF..................................................................... 109 SWAPF ..................................................................... 110 XORLW .................................................................... 110 XORWF .................................................................... 110 Summary Table ........................................................ 104 INT Interrupt (RB0/INT). See Interrupt Sources. INTCON .............................................................................. 15 INTCON Register.......................................................... 13, 15 GIE Bit ........................................................................ 18 INTE Bit ...................................................................... 18 INTF Bit ...................................................................... 18 PEIE Bit ...................................................................... 18 RBIE Bit ...................................................................... 18 RBIF Bit ................................................................ 18, 35 T0IE Bit ....................................................................... 18 Internal Sampling Switch (Rss) Impedance........................ 82 Interrupt Sources .......................................................... 87, 96 Interrupt-on-Change (RB7:RB4) ................................. 35 RB0/INT Pin, External................................................. 97 TMR0 Overflow........................................................... 97 USART Receive/Transmit Complete .......................... 61 Interrupts, Context Saving During....................................... 98 I/O Ports .............................................................................. 33 ID Locations ................................................................ 87, 101 In-Circuit Debugger ..................................................... 87, 101 In-Circuit Serial Programming (ICSP) ......................... 87, 102 INDF Register ......................................................... 13, 14, 15 DS30569C-page 162 2000-2013 Microchip Technology Inc. PIC16F870/871 Interrupts, Enable Bits Global Interrupt Enable (GIE Bit) .......................... 18, 96 Interrupt-on-Change (RB7:RB4) Enable (RBIE Bit) ...................................................... 18, 97 Peripheral Interrupt Enable (PEIE Bit) ........................ 18 RB0/INT Enable (INTE Bit) ......................................... 18 TMR0 Overflow Enable (T0IE Bit)............................... 18 Interrupts, Flag Bits Interrupt-on-Change (RB7:RB4) Flag (RBIF Bit) ........................................ 18, 35, 97 RB0/INT Flag (INTF Bit).............................................. 18 TMR0 Overflow Flag (T0IF Bit) ................................... 97 L Loading of PC ..................................................................... 24 Low Voltage In-Circuit Serial Programming ................ 87, 102 M Master Clear (MCLR) MCLR Reset, Normal Operation ........................... 91, 93 MCLR Reset, SLEEP............................................ 91, 93 MCLR/VPP/THV Pin .......................................................... 7, 8 Memory Organization Data Memory .............................................................. 11 Program Memory ........................................................ 11 Migration from High-End to Enhanced Devices ................ 159 Migration from Mid-Range to Enhanced Devices ............. 158 MPLAB ASM30 Assembler, Linker, Librarian ................... 112 MPLAB ICD 2 In-Circuit Debugger ................................... 113 MPLAB ICE 2000 High Performance Universal In-Circuit Emulator .................................................... 113 MPLAB ICE 4000 High Performance Universal In-Circuit Emulator .................................................... 113 MPLAB Integrated Development Environment Software............................................... 111 MPLINK Object Linker/MPLIB Object Librarian ................ 112 O OPCODE Field Descriptions ............................................. 103 OPTION .............................................................................. 15 OPTION Register ................................................................ 15 OPTION_REG Register ................................................ 14, 17 INTEDG Bit ................................................................. 17 PSA Bit........................................................................ 17 RBPU Bit..................................................................... 17 T0CS Bit...................................................................... 17 T0SE Bit...................................................................... 17 OSC1/CLKI Pin ................................................................. 7, 8 OSC2/CLKO Pin ............................................................... 7, 8 Oscillator Configuration....................................................... 87 HS ......................................................................... 89, 92 LP.......................................................................... 89, 92 RC................................................................... 89, 90, 92 XT ......................................................................... 89, 92 Oscillator, WDT ................................................................... 99 Oscillators Capacitor Selection..................................................... 90 Crystal and Ceramic Resonators ................................ 89 RC............................................................................... 90 2000-2013 Microchip Technology Inc. P Packaging ......................................................................... 149 Marking Information.................................................. 149 Parallel Slave Port (PSP).......................................... 9, 38, 42 Associated Registers.................................................. 43 RE0/RD/AN5 Pin .................................................. 41, 42 RE1/WR/AN6 Pin ................................................. 41, 42 RE2/CS/AN7 Pin .................................................. 41, 42 Select (PSPMODE Bit) ............................. 38, 39, 40, 42 PCL Register .................................................... 13, 14, 15, 24 PCLATH Register ............................................. 13, 14, 15, 24 PCON Register ....................................................... 14, 15, 92 BOR Bit....................................................................... 23 POR Bit....................................................................... 23 PICkit 1 FLASH Starter Kit................................................ 115 PICSTART Plus Development Programmer..................... 113 PIE1 Register ............................................................... 14, 15 PIE2 Register ............................................................... 14, 15 Pinout Descriptions PIC16F870 ................................................................... 7 PIC16F871 ................................................................... 8 PIR1 Register ..................................................................... 13 PIR2 Register ..................................................................... 13 POP .................................................................................... 24 POR. See Power-on Reset. PORTA ............................................................................. 7, 8 Associated Registers.................................................. 34 PORTA Register......................................................... 33 RA0/AN0 Pin ............................................................ 7, 8 RA1/AN1 Pin ............................................................ 7, 8 RA2/AN2/VREF- Pin ...................................................... 7 RA2/AN2/VREF- Pin ...................................................... 8 RA3/AN3/VREF+ Pin ..................................................... 7 RA3/AN3/VREF+ Pin ..................................................... 8 RA4/T0CKI Pin ......................................................... 7, 8 RA5/AN4 Pin ............................................................ 7, 8 TRISA Register........................................................... 33 PORTA Register ................................................................. 13 PORTB ............................................................................. 7, 8 PORTB Register......................................................... 35 Pull-up Enable (RBPU Bit).......................................... 17 RB0/INT Edge Select (INTEDG Bit) ........................... 17 RB0/INT Pin.............................................................. 7, 8 RB0/INT Pin, External ................................................ 97 RB1 Pin .................................................................... 7, 8 RB2 Pin .................................................................... 7, 8 RB3/PGM Pin ........................................................... 7, 8 RB4 Pin .................................................................... 7, 8 RB5 Pin .................................................................... 7, 8 RB6/PGC Pin............................................................ 7, 8 RB7/PGD Pin............................................................ 7, 8 RB7:RB4 Interrupt-on-Change ................................... 97 RB7:RB4 Interrupt-on-Change Enable (RBIE Bit) ......................................... 18, 97 RB7:RB4 Interrupt-on-Change Flag (RBIF Bit)........................................ 18, 35, 97 TRISB Register........................................................... 35 PORTB Register ........................................................... 13, 15 DS30569C-page 163 PIC16F870/871 PORTC.............................................................................. 7, 8 Associated Registers .................................................. 37 PORTC Register ......................................................... 37 RC0/T1OSO/T1CKI Pin ............................................ 7, 8 RC1/T1OSI Pin ......................................................... 7, 8 RC2/CCP1 Pin .......................................................... 7, 8 RC3 Pin..................................................................... 7, 8 RC4 Pin..................................................................... 7, 8 RC5 Pin..................................................................... 7, 8 RC6/TX/CK Pin ................................................... 7, 8, 62 RC7/RX/DT Pin ............................................. 7, 8, 62, 63 TRISC Register ..................................................... 37, 61 PORTC Register ................................................................. 13 PORTD............................................................................ 9, 42 Associated Registers .................................................. 38 Parallel Slave Port (PSP) Function ............................. 38 PORTD Register ......................................................... 38 RD0/PSP0 Pin .............................................................. 9 RD1/PSP1 Pin .............................................................. 9 RD2/PSP2 Pin .............................................................. 9 RD3/PSP3 Pin .............................................................. 9 RD4/PSP4 Pin .............................................................. 9 RD5/PSP5 Pin .............................................................. 9 RD6/PSP6 Pin .............................................................. 9 RD7/PSP7 Pin .............................................................. 9 TRISD Register ........................................................... 38 PORTD Register ................................................................. 13 PORTE.................................................................................. 9 Analog Port Pins ................................................... 41, 42 Associated Registers .................................................. 41 Input Buffer Full Status (IBF Bit) ................................. 40 Input Buffer Overflow (IBOV Bit) ................................. 40 Output Buffer Full Status (OBF Bit)............................. 40 PORTE Register ......................................................... 39 PSP Mode Select (PSPMODE Bit) ........... 38, 39, 40, 42 RE0/RD/AN5 Pin............................................... 9, 41, 42 RE1/WR/AN6 Pin .............................................. 9, 41, 42 RE2/CS/AN7 Pin............................................... 9, 41, 42 TRISE Register ........................................................... 39 PORTE Register ................................................................. 13 Postscaler, WDT Assignment (PSA Bit) ................................................. 17 Power-down Mode. See SLEEP. Power-on Reset (POR) ..................................... 87, 91, 92, 93 Oscillator Start-up Timer (OST) ............................ 87, 92 POR Status (POR Bit)................................................. 23 Power Control (PCON) Register ................................. 92 Power-down (PD Bit) .................................................. 91 Power-up Timer (PWRT) ...................................... 87, 92 Time-out (TO Bit) ........................................................ 91 PR2 ..................................................................................... 15 PR2 Register................................................................. 14, 53 Prescaler, Timer0 Assignment (PSA Bit) ................................................. 17 PRO MATE II Universal Device Programmer ................... 113 Product Identification System............................................ 169 Program Counter RESET Conditions ...................................................... 93 Program Memory ................................................................ 11 Interrupt Vector ........................................................... 11 Map and Stack ............................................................ 11 Paging ......................................................................... 24 RESET Vector............................................................. 11 Program Verification.......................................................... 101 Programming, Device Instructions .................................... 103 DS30569C-page 164 Pulse Width Modulation. See Capture/Compare/PWM, PWM Mode. PUSH.................................................................................. 24 R RAM. See Data Memory. RCREG Register ................................................................ 13 RCSTA Register ................................................................. 13 ADDEN Bit .................................................................. 62 CREN Bit .................................................................... 62 FERR Bit..................................................................... 62 OERR Bit .................................................................... 62 RX9 Bit ....................................................................... 62 RX9D Bit ..................................................................... 62 SPEN Bit............................................................... 61, 62 SREN Bit .................................................................... 62 Register File........................................................................ 11 Register File Map................................................................ 12 Registers ADCON0 (A/D Control 0)............................................ 79 ADCON1 (A/D Control 1)............................................ 80 CCP1CON (CCP Control 1)........................................ 55 EECON1 (EEPROM Control 1) .................................. 28 INTCON ...................................................................... 18 OPTION_REG ...................................................... 17, 46 PCON (Power Control) ............................................... 23 PIE1 (Peripheral Interrupt Enable 1)........................... 19 PIE2 (Peripheral Interrupt Enable 2)........................... 21 PIR1 (Peripheral Interrupt Request Flag 1) ................ 20 PIR2 (Peripheral Interrupt Request Flag 2) ................ 22 RCSTA (Receive Status and Control) ........................ 62 STATUS ..................................................................... 16 T1CON (Timer1 Control) ............................................ 49 T2CON (Timer 2 Control) ........................................... 53 TRISE ......................................................................... 40 TXSTA (Transmit Status and Control) ........................ 61 Reset ............................................................................ 87, 91 MCLR Reset. See MCLR. RESET Conditions for All Registers ........................... 93 RESET Conditions for PCON Register....................... 93 RESET Conditions for Program Counter .................... 93 RESET Conditions for STATUS Register ................... 93 Reset Brown-out Reset (BOR). See Brown-out Reset (BOR). Power-on Reset (POR). See Power-on Reset (POR). WDT Reset. See Watchdog Timer (WDT). Revision History................................................................ 157 S SCI. See USART Serial Communication Interface. See USART. SLEEP .................................................................. 87, 91, 100 Software Simulator (MPLAB SIM) .................................... 112 Software Simulator (MPLAB SIM30) ................................ 112 SPBRG ............................................................................... 15 SPBRG Register................................................................. 14 Special Features of the CPU .............................................. 87 Special Function Registers ................................................. 13 Special Function Register Summary .......................... 13 Speed, Operating.................................................................. 1 SSPADD Register............................................................... 15 SSPSTAT Register ............................................................. 15 Stack................................................................................... 24 Overflows.................................................................... 24 Underflow ................................................................... 24 2000-2013 Microchip Technology Inc. PIC16F870/871 STATUS Register ......................................................... 13, 15 PD Bit.......................................................................... 91 TO Bit.......................................................................... 91 Synchronous Master Reception Associated Registers .................................................. 75 Synchronous Master Transmission Associated Registers .................................................. 73 Synchronous Slave Reception Associated Registers .................................................. 77 Synchronous Slave Transmission Associated Registers .................................................. 76 T T1CKPS0 Bit ....................................................................... 49 T1CKPS1 Bit ....................................................................... 49 T1CON Register ................................................................. 13 T1OSCEN Bit ...................................................................... 49 T1SYNC Bit......................................................................... 49 T2CKPS0 Bit ....................................................................... 53 T2CKPS1 Bit ....................................................................... 53 T2CON Register ................................................................. 13 TAD ...................................................................................... 83 Time-out Sequence............................................................. 92 Timer0 ................................................................................. 45 Associated Registers .................................................. 47 Clock Source Edge Select (T0SE Bit)......................... 17 Clock Source Select (T0CS Bit).................................. 17 External Clock............................................................. 46 Interrupt....................................................................... 45 Overflow Enable (T0IE Bit) ......................................... 18 Overflow Flag (T0IF Bit).............................................. 97 Overflow Interrupt ....................................................... 97 Prescaler..................................................................... 46 T0CKI.......................................................................... 46 Timer1 ................................................................................. 49 Associated Registers .................................................. 52 Asynchronous Counter Mode Reading and Writing to ....................................... 51 Counter Operation ...................................................... 50 Incrementing Edge (figure) ......................................... 50 Operation in Asynchronous Counter Mode................. 51 Operation in Synchronized Counter Mode.................. 50 Operation in Timer Mode ............................................ 50 Oscillator ..................................................................... 51 Capacitor Selection............................................. 51 Prescaler..................................................................... 52 Resetting of Timer1 Register Pair (TMR1H, TMR1L) ............................................... 52 Resetting Timer1 Using a CCP Trigger Output........... 51 TMR1H........................................................................ 51 TMR1L ........................................................................ 51 Timer2 ................................................................................. 53 Associated Registers .................................................. 54 Output ......................................................................... 54 Postscaler ................................................................... 53 Prescaler..................................................................... 53 Prescaler and Postscaler ............................................ 54 Timing Diagrams A/D Conversion......................................................... 135 Asynchronous Master Transmission........................... 67 Asynchronous Master Transmission (Back to Back) .................................................... 67 Asynchronous Reception with Address Byte First .............................................. 71 2000-2013 Microchip Technology Inc. Asynchronous Reception with Address Detect ................................................... 71 Brown-out Reset....................................................... 129 Capture/Compare/PWM (CCP1) .............................. 131 CLKO and I/O ........................................................... 128 External Clock .......................................................... 126 Parallel Slave Port (PSP) Read.................................. 43 Parallel Slave Port (PSP) Write .................................. 43 RESET, Watchdog Timer, Oscillator Start-up Timer and Power-up Timer ................. 129 Slow Rise Time (MCLR Tied to VDD) ......................... 96 Time-out Sequence on Power-up (MCLR Not Tied to VDD) Case 1 ................................................................ 95 Case 2 ................................................................ 95 Time-out Sequence on Power-up (MCLR Tied to VDD) ........................................... 95 Timer0 and Timer1 External Clock ........................... 130 USART Asynchronous Reception .............................. 68 USART Synchronous Receive (Master/Slave) ......... 133 USART Synchronous Reception (Master Mode, SREN) ........................................ 75 USART Synchronous Transmission ........................... 73 USART Synchronous Transmission (Master/Slave) .................................................. 133 Wake-up from SLEEP via Interrupt .......................... 101 Timing Parameter Symbology .......................................... 125 TMR0 Register.............................................................. 13, 15 TMR1CS Bit........................................................................ 49 TMR1H Register ................................................................. 13 TMR1L Register.................................................................. 13 TMR1ON Bit ....................................................................... 49 TMR2 Register.................................................................... 13 TMR2ON Bit ....................................................................... 53 TOUTPS0 Bit ...................................................................... 53 TOUTPS1 Bit ...................................................................... 53 TOUTPS2 Bit ...................................................................... 53 TOUTPS3 Bit ...................................................................... 53 TRISA ................................................................................. 15 TRISA Register................................................................... 14 TRISB ................................................................................. 15 TRISB Register............................................................. 14, 15 TRISC ................................................................................. 15 TRISC Register................................................................... 14 TRISD ................................................................................. 15 TRISD Register................................................................... 14 TRISE ................................................................................. 15 TRISE Register................................................................... 14 IBF Bit......................................................................... 40 IBOV Bit...................................................................... 40 OBF Bit ....................................................................... 40 PSPMODE Bit .......................................... 38, 39, 40, 42 TXREG Register ................................................................. 13 TXSTA ................................................................................ 15 TXSTA Register.................................................................. 14 BRGH Bit .................................................................... 61 CSRC Bit .................................................................... 61 TRMT Bit .................................................................... 61 TX9 Bit........................................................................ 61 TX9D Bit ..................................................................... 61 TXEN Bit ..................................................................... 61 DS30569C-page 165 PIC16F870/871 U W Universal Synchronous Asynchronous Receiver Transmitter. See USART USART ................................................................................ 61 Address Detect Enable (ADDEN Bit) .......................... 62 Asynchronous Mode ................................................... 66 Asynchronous Receive ............................................... 68 Asynchronous Receive (9-bit Mode) ........................... 70 Asynchronous Receive with Address Detect. See Asynchronous Receive (9-bit Mode). Asynchronous Reception ............................................ 69 Asynchronous Transmitter .......................................... 66 Baud Rate Generator (BRG)....................................... 63 Baud Rate Formula............................................. 63 Baud Rates, Asynchronous Mode (BRGH = 0) ................................................. 64 Baud Rates, Asynchronous Mode (BRGH = 1) ................................................. 65 High Baud Rate Select (BRGH Bit)..................... 61 Sampling ............................................................. 63 Clock Source Select (CSRC Bit) ................................. 61 Continuous Receive Enable (CREN Bit) ..................... 62 Framing Error (FERR Bit) ........................................... 62 Overrun Error (OERR Bit) ........................................... 62 Receive Data, 9th bit (RX9D Bit) ................................ 62 Receive Enable, 9-bit (RX9 Bit) .................................. 62 Serial Port Enable (SPEN Bit)............................... 61, 62 Single Receive Enable (SREN Bit) ............................. 62 Synchronous Master Mode ......................................... 72 Synchronous Master Reception .................................. 74 Synchronous Master Transmission............................. 72 Synchronous Slave Mode ........................................... 76 Synchronous Slave Reception .................................... 77 Synchronous Slave Transmit ...................................... 76 Transmit Data, 9th Bit (TX9D)..................................... 61 Transmit Enable (TXEN Bit)........................................ 61 Transmit Enable, Nine-bit (TX9 Bit) ............................ 61 Transmit Shift Register Status (TRMT Bit).................. 61 Wake-up from SLEEP................................................. 87, 100 Interrupts .................................................................... 93 MCLR Reset ............................................................... 93 Timing Diagram ........................................................ 101 WDT Reset ................................................................. 93 Watchdog Timer Register Summary ...................................................... 99 Watchdog Timer (WDT)................................................ 87, 99 Enable (WDTEN Bit)................................................... 99 Postscaler. See Postscaler, WDT. Programming Considerations ..................................... 99 RC Oscillator............................................................... 99 Time-out Period .......................................................... 99 WDT Reset, Normal Operation............................. 91, 93 WDT Reset, SLEEP.............................................. 91, 93 Write Verify Data EEPROM and FLASH Program Memory ........... 31 WWW, On-Line Support ....................................................... 4 DS30569C-page 166 2000-2013 Microchip Technology Inc. PIC16F870/871 THE MICROCHIP WEB SITE CUSTOMER SUPPORT Microchip provides online support via our WWW site at www.microchip.com. This web site is used as a means to make files and information easily available to customers. Accessible by using your favorite Internet browser, the web site contains the following information: Users of Microchip products can receive assistance through several channels: * Product Support - Data sheets and errata, application notes and sample programs, design resources, user's guides and hardware support documents, latest software releases and archived software * General Technical Support - Frequently Asked Questions (FAQ), technical support requests, online discussion groups, Microchip consultant program member listing * Business of Microchip - Product selector and ordering guides, latest Microchip press releases, listing of seminars and events, listings of Microchip sales offices, distributors and factory representatives * * * * Distributor or Representative Local Sales Office Field Application Engineer (FAE) Technical Support Customers should contact their distributor, representative or field application engineer (FAE) for support. Local sales offices are also available to help customers. A listing of sales offices and locations is included in the back of this document. Technical support is available through the web site at: http://microchip.com/support CUSTOMER CHANGE NOTIFICATION SERVICE Microchip's customer notification service helps keep customers current on Microchip products. Subscribers will receive e-mail notification whenever there are changes, updates, revisions or errata related to a specified product family or development tool of interest. To register, access the Microchip web site at www.microchip.com. Under "Support", click on "Customer Change Notification" and follow the registration instructions. 2000-2013 Microchip Technology Inc. DS30569C-page 167 PIC16F870/871 READER RESPONSE It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150. Please list the following information, and use this outline to provide us with your comments about this document. TO: Technical Publications Manager RE: Reader Response Total Pages Sent ________ From: Name Company Address City / State / ZIP / Country Telephone: (_______) _________ - _________ FAX: (______) _________ - _________ Application (optional): Would you like a reply? Y N Device: PIC16F870/871 Literature Number: DS30569C Questions: 1. What are the best features of this document? 2. How does this document meet your hardware and software development needs? 3. Do you find the organization of this document easy to follow? If not, why? 4. What additions to the document do you think would enhance the structure and subject? 5. What deletions from the document could be made without affecting the overall usefulness? 6. Is there any incorrect or misleading information (what and where)? 7. How would you improve this document? DS30569C-page 168 2000-2013 Microchip Technology Inc. PIC16F870/871 PIC16F870/871 PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. PART NO. -X /XX XXX Device Temperature Range Package Pattern Examples: a) b) Device PIC16F870, PIC16F870T; VDD range 4.0V to 5.5V PIC16F871, PIC16F871T ; VDD range 4.0V to 5.5V PIC16LF870X, PIC16LF870T; VDD range 2.0V to 5.5V PIC16LF871X, PIC16LF871T; VDD range 2.0V to 5.5V F LP T = = = Normal VDD limits Extended VDD limits In Tape and Reel - SOIC, SSOP, TQFP and PLCC packages only. Temperature Range blank(3) = I = Package PQ PT SO SP SS P L Pattern QTP, Code or Special Requirements (blank otherwise) = = = = = = = c) d) PIC16F870-I/SP 301 = Industrial temp., PDIP package, 20 MHz, normal VDD limits, QTP pattern #301. PIC16F871-I/PT = Industrial temp., TQFP package, 20 MHz, Extended VDD limits. PIC16F871-I/P = Industrial temp., PDIP package, 20 MHz, normal VDD limits. PIC16LF870-I/SS = Industrial temp., SSOP package, DC - 20 MHz, extended VDD limits. 0C to +70C (Commercial) -40C to +85C (Industrial) MQFP (Metric PQFP) TQFP (Thin Quad Flatpack) SOIC Skinny Plastic Dip SSOP PDIP PLCC Sales and Support Data Sheets Products supported by a preliminary Data Sheet may have an errata sheet describing minor operational differences and recommended workarounds. To determine if an errata sheet exists for a particular device, please contact one of the following: 1. 2. Your local Microchip sales office The Microchip Worldwide Site (www.microchip.com) 2000-2013 Microchip Technology Inc. DS30569C-page 169 PIC16F870/871 NOTES: 2000-2013 Microchip Technology Inc. DS30569C-page 170 Note the following details of the code protection feature on Microchip devices: * Microchip products meet the specification contained in their particular Microchip Data Sheet. * Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. * There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip's Data Sheets. Most likely, the person doing so is engaged in theft of intellectual property. * Microchip is willing to work with the customer who is concerned about the integrity of their code. * Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as "unbreakable." Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our products. Attempts to break Microchip's code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act. Information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights. Trademarks The Microchip name and logo, the Microchip logo, dsPIC, FlashFlex, KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro, PICSTART, PIC32 logo, rfPIC, SST, SST Logo, SuperFlash and UNI/O are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. FilterLab, Hampshire, HI-TECH C, Linear Active Thermistor, MTP, SEEVAL and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A. Silicon Storage Technology is a registered trademark of Microchip Technology Inc. in other countries. Analog-for-the-Digital Age, Application Maestro, BodyCom, chipKIT, chipKIT logo, CodeGuard, dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN, ECONOMONITOR, FanSense, HI-TIDE, In-Circuit Serial Programming, ICSP, Mindi, MiWi, MPASM, MPF, MPLAB Certified logo, MPLIB, MPLINK, mTouch, Omniscient Code Generation, PICC, PICC-18, PICDEM, PICDEM.net, PICkit, PICtail, REAL ICE, rfLAB, Select Mode, SQI, Serial Quad I/O, Total Endurance, TSHARC, UniWinDriver, WiperLock, ZENA and Z-Scale are trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. SQTP is a service mark of Microchip Technology Incorporated in the U.S.A. GestIC and ULPP are registered trademarks of Microchip Technology Germany II GmbH & Co. & KG, a subsidiary of Microchip Technology Inc., in other countries. All other trademarks mentioned herein are property of their respective companies. (c) 2000-2013, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. Printed on recycled paper. ISBN: 9781620769379 QUALITY MANAGEMENT SYSTEM CERTIFIED BY DNV == ISO/TS 16949 == 2000-2013 Microchip Technology Inc. Microchip received ISO/TS-16949:2009 certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona; Gresham, Oregon and design centers in California and India. The Company's quality system processes and procedures are for its PIC(R) MCUs and dsPIC(R) DSCs, KEELOQ(R) code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and analog products. In addition, Microchip's quality system for the design and manufacture of development systems is ISO 9001:2000 certified. DS30569C-page 171 Worldwide Sales and Service AMERICAS ASIA/PACIFIC ASIA/PACIFIC EUROPE Corporate Office 2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 480-792-7200 Fax: 480-792-7277 Technical Support: http://www.microchip.com/ support Web Address: www.microchip.com Asia Pacific Office Suites 3707-14, 37th Floor Tower 6, The Gateway Harbour City, Kowloon Hong Kong Tel: 852-2401-1200 Fax: 852-2401-3431 India - Bangalore Tel: 91-80-3090-4444 Fax: 91-80-3090-4123 India - New Delhi Tel: 91-11-4160-8631 Fax: 91-11-4160-8632 Austria - Wels Tel: 43-7242-2244-39 Fax: 43-7242-2244-393 Denmark - Copenhagen Tel: 45-4450-2828 Fax: 45-4485-2829 India - Pune Tel: 91-20-2566-1512 Fax: 91-20-2566-1513 France - Paris Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79 Japan - Osaka Tel: 81-6-6152-7160 Fax: 81-6-6152-9310 Germany - Munich Tel: 49-89-627-144-0 Fax: 49-89-627-144-44 Atlanta Duluth, GA Tel: 678-957-9614 Fax: 678-957-1455 Boston Westborough, MA Tel: 774-760-0087 Fax: 774-760-0088 Chicago Itasca, IL Tel: 630-285-0071 Fax: 630-285-0075 Cleveland Independence, OH Tel: 216-447-0464 Fax: 216-447-0643 Dallas Addison, TX Tel: 972-818-7423 Fax: 972-818-2924 Detroit Farmington Hills, MI Tel: 248-538-2250 Fax: 248-538-2260 Indianapolis Noblesville, IN Tel: 317-773-8323 Fax: 317-773-5453 Los Angeles Mission Viejo, CA Tel: 949-462-9523 Fax: 949-462-9608 Santa Clara Santa Clara, CA Tel: 408-961-6444 Fax: 408-961-6445 Toronto Mississauga, Ontario, Canada Tel: 905-673-0699 Fax: 905-673-6509 Australia - Sydney Tel: 61-2-9868-6733 Fax: 61-2-9868-6755 China - Beijing Tel: 86-10-8569-7000 Fax: 86-10-8528-2104 China - Chengdu Tel: 86-28-8665-5511 Fax: 86-28-8665-7889 China - Chongqing Tel: 86-23-8980-9588 Fax: 86-23-8980-9500 Netherlands - Drunen Tel: 31-416-690399 Fax: 31-416-690340 Korea - Daegu Tel: 82-53-744-4301 Fax: 82-53-744-4302 Spain - Madrid Tel: 34-91-708-08-90 Fax: 34-91-708-08-91 China - Hangzhou Tel: 86-571-2819-3187 Fax: 86-571-2819-3189 Korea - Seoul Tel: 82-2-554-7200 Fax: 82-2-558-5932 or 82-2-558-5934 China - Hong Kong SAR Tel: 852-2943-5100 Fax: 852-2401-3431 Malaysia - Kuala Lumpur Tel: 60-3-6201-9857 Fax: 60-3-6201-9859 China - Nanjing Tel: 86-25-8473-2460 Fax: 86-25-8473-2470 Malaysia - Penang Tel: 60-4-227-8870 Fax: 60-4-227-4068 China - Qingdao Tel: 86-532-8502-7355 Fax: 86-532-8502-7205 Philippines - Manila Tel: 63-2-634-9065 Fax: 63-2-634-9069 China - Shanghai Tel: 86-21-5407-5533 Fax: 86-21-5407-5066 Singapore Tel: 65-6334-8870 Fax: 65-6334-8850 China - Shenyang Tel: 86-24-2334-2829 Fax: 86-24-2334-2393 Taiwan - Hsin Chu Tel: 886-3-5778-366 Fax: 886-3-5770-955 China - Shenzhen Tel: 86-755-8864-2200 Fax: 86-755-8203-1760 Taiwan - Kaohsiung Tel: 886-7-213-7828 Fax: 886-7-330-9305 China - Wuhan Tel: 86-27-5980-5300 Fax: 86-27-5980-5118 Taiwan - Taipei Tel: 886-2-2508-8600 Fax: 886-2-2508-0102 China - Xian Tel: 86-29-8833-7252 Fax: 86-29-8833-7256 Thailand - Bangkok Tel: 66-2-694-1351 Fax: 66-2-694-1350 UK - Wokingham Tel: 44-118-921-5869 Fax: 44-118-921-5820 China - Xiamen Tel: 86-592-2388138 Fax: 86-592-2388130 China - Zhuhai Tel: 86-756-3210040 Fax: 86-756-3210049 DS30569C-page 172 Italy - Milan Tel: 39-0331-742611 Fax: 39-0331-466781 Japan - Tokyo Tel: 81-3-6880- 3770 Fax: 81-3-6880-3771 11/29/12 2000-2013 Microchip Technology Inc.