January 19, 2000 SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 Configurable Communications Controllers with EE/Flash Program Memory, In-System Programming Capability and On-Chip Debug 1.0 1.1 PRODUCT OVERVIEW Introduction teristics enables the device to implement hard real-time functions as software modules (Virtual PeripheralTM) to replace traditional hardware functions. The Scenix SX family of configurable communications controllers are fabricated in an advanced CMOS process technology. The advanced process, combined with a RISC-based architecture, allows high-speed computation, flexible I/O control, and efficient data manipulation. Throughput is enhanced by operating the device at frequencies up to 50/75 MHz and by optimizing the instruction set to include mostly single-cycle instructions. In addition, the SX architecture is deterministic and totally reprogramable. The unique combination of these charac- On-chip functions include a general-purpose 8-bit timer with prescaler, an analog comparator, a brown-out detector, a watchdog timer, a power-save mode with multisource wakeup capability, an internal R/C oscillator, userselectable clock modes, and high-current outputs. RT C C O S C 1 O S C2 O SC 8-bit W atchdog 8-bit T im er Clock D river RT C C T im er (W DT ) S elect 4M Hz Internal / 4 or / 1 RC OSC Interrupt Stack System C lock 8 M C LR Prescaler for R T CC P ow er-O n A nalog 3 or R eset Interrupt RE S ET M IW U P ort B C om p P rescaler for W DT B row n-O ut 8 8 8 M IW U S ystem C lock Internal D ata B us 8 8 8 8 8 8 8 8 W In-System PC D ebugging Port A Port C 3 Level 8 A LU FSR A ddress S tack Fetch In-S ystem 4 8 Instruction PC P rogram m ing Decode Pipeline 136 Bytes STATU S S R AM E xecutive 2k W ords A ddress 12 E E P RO M O PT IO N W rite Back MODE 8 W rite D ata R ead D ata 8 Instruction 12 IR E A D Figure 1-1. Block Diagram ScenixTM and the Scenix logo are trademarks of Scenix Semiconductor, Inc. I2CTM is a trademark of Philips Corporation MicrowireTM is a trademark of National Semiconductor Corporation (c) 2000 Scenix Semiconductor, Inc. All rights reserved. All other trademarks mentioned in this document are property of their respective companies. -1- www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 Table of Contents 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 Product 1.1 1.2 1.3 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Key Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.3.1 The Virtual Peripheral Concept . . . . . . . . 4 1.3.2 The Communications Controller . . . . . . . . 4 1.4 Programming and Debugging Support . . . . . . . . . . 4 1.5 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Connection Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1 Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.2 Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.3 Part Numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Port Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.1 Reading and Writing the Ports . . . . . . . . . . . . . . . . . 7 3.1.1 Read-Modify-Write Considerations . . . . . 9 3.2 Port Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.2.1 MODE Register . . . . . . . . . . . . . . . . . . . . 9 3.2.2 Port Configuration Registers . . . . . . . . . . 9 3.2.3 Port Configuration Upon Reset . . . . . . . 10 Special-Function Registers . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.1 PC Register (02h) . . . . . . . . . . . . . . . . . . . . . . . . . 11 4.2 STATUS Register (03h) . . . . . . . . . . . . . . . . . . . . . 11 4.3 OPTION Register . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Device Configuration Registers . . . . . . . . . . . . . . . . . . . . . 13 5.1 FUSE Word (Read/Program at FFFh in main memory map) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 5.2 FUSEX Word (Read/Program via Programming Command) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 5.3 DEVICE Word (Hard-Wired Read-Only) . . . . . . . . 14 Memory Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 6.1 Program Memory . . . . . . . . . . . . . . . . . . . . . . . . . . 15 6.1.1 Program Counter . . . . . . . . . . . . . . . . . . 15 6.1.2 Subroutine Stack . . . . . . . . . . . . . . . . . . 15 6.2 Data Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 6.2.1 File Select Register (04h) . . . . . . . . . . . 15 Power Down Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 7.1 Multi-Input Wakeup . . . . . . . . . . . . . . . . . . . . . . . . 17 7.2 Port B MIWU/Interrupt Configuration . . . . . . . . . . . 18 Interrupt Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Oscillator Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 9.1 XT, LP or HS modes . . . . . . . . . . . . . . . . . . . . . . . 21 9.2 External RC Mode . . . . . . . . . . . . . . . . . . . . . . . . . 23 9.3 Internal RC Mode . . . . . . . . . . . . . . . . . . . . . . . . . . 23 (c) 2000 Scenix Semiconductor, Inc. All rights reserved. 11.0 12.0 13.0 14.0 15.0 16.0 17.0 18.0 -2- Real Time Clock (RTCC)/Watchdog Timer . . . . . . . . . . . . .23 10.1 RTCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 10.2 Watchdog Timer . . . . . . . . . . . . . . . . . . . . . . . . . . .23 10.3 The Prescaler . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 Comparator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 Brown-Out Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 Register States Upon DiffeRent reset operations . . . . . . .29 Instruction Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 15.1 Instruction Set Features . . . . . . . . . . . . . . . . . . . . .30 15.2 Instruction Execution . . . . . . . . . . . . . . . . . . . . . . .30 15.3 Addressing Modes . . . . . . . . . . . . . . . . . . . . . . . . .30 15.4 RAM Addressing . . . . . . . . . . . . . . . . . . . . . . . . . .31 15.5 The Bank Instruction . . . . . . . . . . . . . . . . . . . . . . .31 15.6 Bit Manipulation . . . . . . . . . . . . . . . . . . . . . . . . . . .31 15.7 Input/Output Operation . . . . . . . . . . . . . . . . . . . . . .31 15.8 Increment/Decrement . . . . . . . . . . . . . . . . . . . . . . .31 15.9 Loop Counting and Data Pointing Testing . . . . . . .31 15.10 Branch and Loop Call Instructions . . . . . . . . . . . . .31 15.10.1 Jump Operation . . . . . . . . . . . . . . . . . . .31 15.10.2 Page Jump Operation . . . . . . . . . . . . . .32 15.10.3 Call Operation . . . . . . . . . . . . . . . . . . . .32 15.10.4 Page Call Operation . . . . . . . . . . . . . . . .32 15.11 Return Instructions . . . . . . . . . . . . . . . . . . . . . . . . .32 15.12 Subroutine Operation . . . . . . . . . . . . . . . . . . . . . . .33 15.12.1 Push Operation . . . . . . . . . . . . . . . . . . .33 15.12.2 Pop Operation . . . . . . . . . . . . . . . . . . . .33 15.13 Comparison and Conditional Branch Instructions .34 15.14 Logical Instruction . . . . . . . . . . . . . . . . . . . . . . . . .34 15.15 Shift and Rotate Instructions . . . . . . . . . . . . . . . . .34 15.16 Complement and SWAP . . . . . . . . . . . . . . . . . . . .34 15.17 Key to Abbreviations and Symbols . . . . . . . . . . . . .34 Instruction Set Summary Table . . . . . . . . . . . . . . . . . . . . . .35 16.1 Equivalent Assembler Mnemonics . . . . . . . . . . . . .38 Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . .39 17.1 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . .39 17.2 DC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . .40 17.3 AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . .41 17.4 DC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . .42 17.5 AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . .43 17.6 Comparator DC and AC Specifications . . . . . . . . .43 17.7 Typical Performance Characteristics. . . . . . . . . . . .44 Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47 www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 1.2 Key Features Hardware Peripheral Features * One 8-bit Real Time Clock/Counter (RTCC) with programable 8-bit prescaler * Watchdog Timer (shares the RTCC prescaler) * Analog comparator * Brown-out detector * Multi-Input Wakeup logic on 8 pins * Internal RC oscillator with configurable rate from 31.25 kHz to 4 MHz * Power-On-Reset 50 MIPS Performance * SX18AC/SX20AC/SX28AC: DC - 50 MHz operation SX18AC75/SX20AC75/SX28AC75: DC - 75 MHz * SX18AC/SX20AC/SX28AC: 20 ns instruction cycle, 60 ns internal interrupt response SX18AC75/SX20AC75/SX28AC75: 13.3 ns instruction cycle, 39.9 ns internal interrupt response * 1 instruction per clock (branches 3) EE/FLASH Program Memory and SRAM Data Memory * * * * Packages * 18-pin SOP/DIP, 20-pin SSOP, 28-pin SOP/DIP/SSOP Access time of < 10 ns provides single cycle access EE/Flash rated for > 10,000 rewrite cycles 2048 Words EE/Flash program memory 136x8 bits SRAM data memory Programming and Debugging Support * On- chip in-system programming support with serial and parallel interfaces * In-system serial programming via oscillator pins * On-chip in-System debugging support logic * Real-time emulation, full program debug, and integrated development environment offered by third party tool vendors CPU Features * Compact instruction set * All instructions are single cycle except branch * Eight-level push/pop hardware stack for subroutine linkage * Fast table lookup capability through run-time readable code (IREAD instruction) * Totally predictable program execution flow for hard real-time applications Fast and Deterministic Interrupt * Jitter-free 3-cycle internal interrupt response * Hardware context save/restore of key resources such as PC, W, STATUS, and FSR within the 3-cycle interrupt response time * External wakeup/interrupt capability on Port B (8 pins) Flexible I/O * * * * * * * All pins individually programmable as I/O Inputs are TTL or CMOS level selectable All pins have selectable internal pull-ups Selectable Schmitt Trigger inputs on Ports B, and C All outputs capable of sourcing/sinking 30 mA Port A outputs have symmetrical drive Analog comparator support on Port B (RB0 OUT, RB1 IN-, RB2 IN+) * Selectable I/O operation synchronous to the oscillator clock (c) 2000 Scenix Semiconductor, Inc. All rights reserved. -3- www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 1.3 Architecture * * * * The SX devices use a modified Harvard architecture. This architecture uses two separate memories with separate address buses, one for the program and one for data, while allowing transfer of data from program memory to SRAM. This ability allows accessing data tables from program memory. The advantage of this architecture is that instruction fetch and memory transfers can be overlapped with a multi-stage pipeline, which means the next instruction can be fetched from program memory while the current instruction is being executed using data from the data memory. Delta/Sigma ADC DTMF generation/detection PSK/FSK generation/detection FFT/DFT based algorithms 1.3.2 The Communications Controller The combination of the Scenix hardware architecture and the Virtual Peripheral concept create a powerful, creative platform for the communications design communities: SX communications controller. Its high processing power, recofigurability, cost-effectiveness, and overall design freedom give the designer the power to build products for the future with the confidence of knowing that they can keep up with innovation in standards and other areas. Scenix has developed a revolutionary RISC-based architecture and memory design techniques that is 20 times faster than conventional MCUs, deterministic, jitter free, and totally reprogramable. 1.4 Programming and Debugging Support The SX devices are currently supported by third party tool vendors. On-chip in-system debug capabilities have been added, allowing tools to provide an integrated development environment including editor, macro assembler, debugger, and programmer. Un-obtrusive in-system programming is provided through the OSC pins. There is no need for a bon-out chip, so the user does not have to worry about the potential variations in electrical characteristics of a bond-out chip and the actual chip used in the target applications. the user can test and revise the fully debugged code in the actual SX, in the actual application, and get to production much faster. The SX family implements a four-stage pipeline (fetch, decode, execute, and write back), which results in execution of one instruction per clock cycle. For example, at the maximum operating frequency of 50 MHz, instructions are executed at the rate of one per 20-ns clock cycle. 1.3.1 The Virtual Peripheral Concept Virtual Peripheral concept enables the "software system on a chip" approach. Virtual Peripheral, a software module that replaces a traditional hardware peripheral, takes advantage of the Scenix architecture's high performance and deterministic nature to produce same results as the hardware peripheral with much greater flexibility. 1.5 Applications Emerging applications and advances in existing ones require higher performance while maintaining low cost and fast time-to-production. The speed and flexibility of the Scenix architecture complemented with the availability of the Virtual Peripheral library, simultaneously address a wide range of engineering and product development concerns. They decrease the product development cycle dramatically, shortening time to production to as little as a few days. The device provides solutions for many familiar applications such as process controllers, electronic appliances/tools, security/monitoring systems, consumer automotive, sound generation, motor control, and personal communication devices. In addition, the device is suitable for applications that require DSP-like capabilities, such as closed-loop servo control (digital filters), digital answering machines, voice notation, interactive toys, and magnetic-stripe readers. Scenix's time-saving Virtual Peripheral library gives the system designers a choice of ready-made solutions, or a head start on developing their own peripherals. So, with Virtual Peripheral modules handling established functions, design engineers can concentrate on adding value to other areas of the application. Furthermore, the growing Virtual Peripheral library features new components, such as the Internet Protocol stack, and communication interfaces, that allow design engineers to embed Internet connectivity into all of their products at extremely low cost and very little effort. The concept of Virtual Peripheral combined with in-system re-programmability provides a power development platform ideal for the communications industry because of the numerous and rapidly evolving standards and protocols. Overall, the concept of Virtual Peripheral provides benefits such as using a more simple device, reduced component count, fast time to market, increased flexibility in design, customization to your application, and ultimately overall system cost reduction. Some examples of Virtual Peripheral modules are: * Communication interfaces such as I2CTM, MicrowireTM (-Wire), SPI, IrDA Stack, UART, and Modem functions * Frequency generation and measurement * PPM/PWM output (c) 2000 Scenix Semiconductor, Inc. All rights reserved. -4- www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 2.0 CONNECTION DIAGRAMS 2.1 Pin Assignments SX 28-PIN SX 20-PIN SX 18-PIN RA2 RA3 RTCC MCLR Vss RB0 RB1 RB2 RB3 1 2 3 4 5 6 7 8 9 18 17 16 15 14 13 12 11 10 RA1 RA0 OSC1 OSC2 Vdd RB7 RB6 RB5 RB4 RA2 RA3 RTCC MCLR Vss Vss RB0 RB1 RB2 RB3 1 2 3 4 5 6 7 8 9 10 DIP/SOP 20 19 18 17 16 15 14 13 12 11 RTCC Vdd n.c. Vss n.c. RA0 RA1 RA2 RA3 RB0 RB1 RB2 RB3 RB4 RA1 RA0 OSC1 OSC2 Vdd Vdd RB7 RB6 RB5 RB4 SSOP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 DIP/SOP 2.2 SX 28-PIN MCLR OSC1 OSC2 RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 RB7 RB6 RB5 Vss RTCC Vdd Vdd RA0 RA1 RA2 RA3 RB0 RB1 RB2 RB3 RB4 Vss 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 MCLR OSC1 OSC2 RC7 RC6 RC5 RC4 RC3 RC2 RC1 RC0 RB7 RB6 RB5 SSOP Pin Descriptions Name Pin Type Input Levels Description RA0 I/O TTL/CMOS Bidirectional I/O Pin; symmetrical source / sink capability RA1 I/O TTL/CMOS Bidirectional I/O Pin; symmetrical source / sink capability Bidirectional I/O Pin; symmetrical source / sink capability RA2 I/O TTL/CMOS RA3 I/O TTL/CMOS Bidirectional I/O Pin; symmetrical source / sink capability RB0 I/O TTL/CMOS/ST Bidirectional I/O Pin; comparator output; MIWU input RB1 I/O TTL/CMOS/ST Bidirectional I/O Pin; comparator negative input; MIWU input RB2 I/O TTL/CMOS/ST Bidirectional I/O Pin; comparator positive input; MIWU input RB3 I/O TTL/CMOS/ST Bidirectional I/O Pin; MIWU input RB4 I/O TTL/CMOS/ST Bidirectional I/O Pin; MIWU input RB5 I/O TTL/CMOS/ST Bidirectional I/O Pin; MIWU input RB6 I/O TTL/CMOS/ST Bidirectional I/O Pin; MIWU input RB7 I/O TTL/CMOS/ST Bidirectional I/O Pin; MIWU input RC0 I/O TTL/CMOS/ST Bidirectional I/O pin RC1 I/O TTL/CMOS/ST Bidirectional I/O pin RC2 I/O TTL/CMOS/ST Bidirectional I/O pin RC3 I/O TTL/CMOS/ST Bidirectional I/O pin RC4 I/O TTL/CMOS/ST Bidirectional I/O pin RC5 I/O TTL/CMOS/ST Bidirectional I/O pin RC6 I/O TTL/CMOS/ST Bidirectional I/O pin RC7 I/O TTL/CMOS/ST Bidirectional I/O pin Input to Real-Time Clock/Counter RTCC I ST MCLR I ST Master Clear reset input - active low OSC1/In/Vpp I ST Crystal oscillator input - external clock source input Crystal oscillator output - in R/C mode, internally pulled to Vdd through weak OSC2/Out O CMOS pull-up Vdd Positive supply pin P - Ground pin Vss P - Note:I = input, O = output, I/O = Input/Output, P = Power, TTL = TTL input, CMOS = CMOS input, ST = Schmitt Trigger input, MIWU = Multi-Input Wakeup input (c) 2000 Scenix Semiconductor, Inc. All rights reserved. -5- www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 2.3 Part Numbering Table 2-1. Ordering Information Pins I/O Operating Frequency (MHz) EE/Flash (Words) RAM (Bytes) Operating Temp. (C) SX18AC/SO SX18AC-I/SO SX18AC75/SO 18 18 18 12 12 12 50 50 75 2K 2K 2K 136 136 136 0C to +70C -40C to +85C 0C to +70C SX18AC/DP SX18AC-I/DP SX18AC75/DP 18 18 18 12 12 12 50 50 75 2K 2K 2K 136 136 136 0C to +70C -40C to +85C 0C to +70C SX20AC/SS SX20AC-I/SS SX20AC75/SS 20 20 20 12 12 12 50 50 75 2K 2K 2K 136 136 136 0C to +70C -40C to +85C 0C to +70C SX28AC/SO SX28AC-I/SO SX28AC75/SO 28 28 28 20 20 20 50 50 75 2K 2K 2K 136 136 136 0C to +70C -40C to +85C 0C to +70C SX28AC/DP SX28AC-I/DP SX28AC75/DP 28 28 28 20 20 20 50 50 75 2K 2K 2K 136 136 136 0C to +70C -40C to +85C 0C to +70C SX28AC/SS SX28AC-I/SS SX28AC75/SS 28 28 28 20 20 20 50 50 75 2K 2K 2K 136 136 136 0C to +70C -40C to +85C 0C to +70C Device SX18ACXX-I/SO Package Type DP = DIP SO = SOP SS = SSOP TQ = Tiny PQFP PQ = PQFP Extended Temperature Speed Memory Size Blank = 50 MHz 75 = 75 MHz 100 = 100 MHz Feature Set Blank = 0C to +70C I= -40C to +85C Pin Count SceniX A= 512 word B= 1k word C= 2k word D= 4k word Figure 2-1. Part Number Reference Guide (c) 2000 Scenix Semiconductor, Inc. All rights reserved. -6- www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 3.0 PORT DESCRIPTIONS The associated registers allow for each port bit to be individually configured under software control as shown below: The device contains a 4-bit I/O port (Port A) and two 8-bit I/O ports (Port B, Port C). Port A provides symmetrical drive capability. Each port has three associated 8-bit registers (Direction, Data, TTL/CMOS Select, and Pull-Up Enable) to configure each port pin as Hi-Z input or output, to select TTL or CMOS voltage levels, and to enable/disable the weak pull-up resistor. The upper four bits of the registers associated with Port A are not used. The least significant bit of the registers corresponds to the least significant port pin. To access these registers, an appropriate value must be written into the MODE register. Table 3-1. Port Configuration Data Direction Registers: RA, RB, RC Upon power-up, all bits in these registers are initialized to "1". TTL/CMOS Select Registers: LVL_A, LVL_B, LVL_C Pullup Enable Registers: PLP_A, PLP_B, PLP_C 0 1 0 1 0 1 Output Hi-Z Input CMOS TTL Enable Disable Mode = 0F Mode = 0E Mode = 0D MODE WR Vdd RA Direction Internal Data Bus 0 = Output 1 = Hi-Z Input Pullup WR PLP_A 0 = Pullup Enable 1 = Pullup Disable WR RA Data Port A PIN WR LVL_A 0 = CMOS 1 = TTL TTL Buffer M U CMOS Buffer X RD Port A INPUT Figure 3-1. Port A Configuration 3.1 Reading and Writing the Ports Writing to a port data register sets the voltage levels of the corresponding port pins that have been configured to operate as outputs. Reading from a register reads the voltage levels of the corresponding port pins that have been configured as inputs. The three ports are memory-mapped into the data memory address space. To the CPU, the three ports are available as the RA, RB, and RC file registers at data memory addresses 05h, 06h, and 07h, respectively. (c) 2000 Scenix Semiconductor, Inc. All rights reserved. -7- www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 Mode = 0F Mode = 0E Mode = 0D Mode = 0C MODE Vdd WR RB or RC Direction Pullup Resistor (~20k) 0 = Output 1 = Hi-Z Input WR Internal Data Bus PLP_B or PLP_C WR 0 = Pullup Enable 1 = Pullup Disable Port B or Port C PIN RB or RC Data WR LVL_B or LVL_C 0 = CMOS 1 = TTL WR TTL Buffer M U CMOS Buffer X ST_B or ST_C 0 = Schmitt Trigger Enable 1 = Schmitt Trigger Disable M U X RD Port B: Input, MIWU, Comparator Port C: Input Only ~ ~ Schmitt Trigger Buffer Figure 3-2. Port B, Port C Configuration For example, suppose all four Port A pins are configured as outputs and with RA0 and RA1 to be high, and RA2 and RA3 to be low: mov W,#$03 mov $05,W When a write is performed to a bit position for a port that has been configured as an input, a write to the port data register is still performed, but it has no immediate effect on the pin. If later that pin is configured to operate as an output, it will reflect the value that has been written to the data register. ;load W with the value 03h ;(bits 0 and 1 high) ;write 03h to Port A data ;register When a read is performed from a bit position for a port, the operation is actually reading the voltage level on the pin itself, not necessarily the bit value stored in the port data register. This is true whether the pin is configured to operate as an input or an output. Therefore, with the pin configured to operate as an input, the data register contents have no effect on the value that you read. With the pin configured to operate as an output, what is read generally matches what has been written to the register. The second "mov" instruction in this example writes the Port A data register (RA), which controls the output levels of the four Port A pins, RA0 through RA3. Because Port A has only four I/O pins, only the four least significant bits of this register are used. The four high-order register bits are "don't care" bits. Port B and Port C are both eight bits wide, so the full widths of the RB and RC registers are used. (c) 2000 Scenix Semiconductor, Inc. All rights reserved. -8- www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 After a value is written to the MODE register, that setting remains in effect until it is changed by writing to the MODE register again. For example, you can write the value 0Eh to the MODE register just once, and then write to each of the three pullup configuration registers using the three "mov !rx,W" instructions. 3.1.1 Read-Modify-Write Considerations Caution must be exercised when performing two successive read-modify-write instructions (SETB or CLRB operations) on I/O port pin. Input data used for an instruction must be valid during the time the instruction is executed, and the output result from an instruction is valid only after that instruction completes its operation. Unexpected results from successive read-modify-write operations on I/O pins can occur when the device is running at high speeds. Although the device has an internal write-back section to prevent such conditions, it is still recommended that the user program include a NOP instruction as a buffer between successive read-modify-write instructions performed on I/O pins of the same port. Table 3-3. MODE Register and Port Control Register Access MODE Reg. mov !RA,W mov !RB,W mov !RC,W 08h not used CMP_B not used Also note that reading an I/O port is actually reading the pins, not the output data latches. That is, if the pin output driver is enabled and driven high while the pin is held low externally, the port pin will read low. 09h not used WKPND_B not used 0Ah not used WKED_B not used 0Bh not used WKEN_B not used 3.2 0Ch not used ST_B ST_C 0Dh LVL_A LVL_B LVL_C 0Eh PLP_A PLP_B PLP_C 0Fh RA Direction RB Direction RC Direction Port Configuration Each port pin offers the following configuration options: * data direction * input voltage levels (TTL or CMOS) * pullup type (pullup resistor enable or disable) * Schmitt trigger input (for Port B and Port C only) Port B offers the additional option to use the port pins for the Multi-Input Wakeup/Interrupt function and/or the analog comparator function. The following code example shows how to program the pullup control registers. Port configuration is performed by writing to a set of control registers associated with the port. A special-purpose instruction is used to write these control registers: * mov !RA,W (move W to Port A control register) * mov !RB,W (move W to Port B control register) * mov !RC,W (move W to Port C control register) Each one of these instructions writes a port control register for Port A, Port B, or Port C. There are multiple control registers for each port. To specify which one you want to access, you use another register called the MODE register. M,#$0E ;MODE=0Eh to access port pullup ;registers mov mov W,#$03 !RA,W ;W = 0000 0011 ;disable pullups for A0 and A1 mov mov W,#$FF !RB,W ;W = 1111 1111 ;disable all pullups for B0-B7 mov mov W,#$00 !RC,W ;W = 0000 0000 ;enable all pullups for C0-C7 First the MODE register is loaded with 0Eh to select access to the pullup control registers (PLP_A, PLP_B, and PLP_C). Then the MOV !rx,W instructions are used to specify which port pins are to be connected to the internal pullup resistors. Setting a bit to 1 disconnects the corresponding pullup resistor, and clearing a bit to 0 connects the corresponding pullup resistor. 3.2.1 MODE Register The MODE register controls access to the port configuration registers. Because the MODE register is not memory-mapped, it is accessed by the following specialpurpose instructions: 3.2.2 Port Configuration Registers * mov M, #lit (move literal to MODE register) * mov M,W (move W to MODE register) * mov W,M (move MODE register to W) The value contained in the MODE register determines which port control register is accessed by the "mov !rx,W" instruction as indicated in Table 3-3. MODE register values not listed in the table are reserved for future expansion and should not be used. Therefore, the MODE register should always contain a value from 08h to 0Fh. Upon reset, the MODE register is initialized to 0Fh, which enables access to the port direction registers. (c) 2000 Scenix Semiconductor, Inc. All rights reserved. mov The port configuration registers that you control with the MOV !rx,W instruction operate as described below. RA, RB, and RC Data Direction Registers (MODE=0Fh) Each register bit sets the data direction for one port pin. Set the bit to 1 to make the pin operate as a high-impedance input. Clear the bit to 0 to make the pin operate as an output. -9- www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 PLP_A, PLP_B, and PLP_C: Pullup Enable Registers (MODE=0Eh) WKPND_B: Wakeup Pending Bit Register (MODE=09h) Each register bit determines whether an internal pullup resistor is connected to the pin. Set the bit to 1 to disconnect the pullup resistor or clear the bit to 0 to connect the pullup resistor. When you access the WKPND_B register using MOV !RB,W, the CPU does an exchange between the contents of W and WKPND_B. This feature lets you read the WKPND_B register contents. Each bit indicates the status of the corresponding MIWU pin. A bit set to 1 indicates that a valid edge has occurred on the corresponding MIWU pin, triggering a wakeup or interrupt. A bit set to 0 indicates that no valid edge has occurred on the MIWU pin. LVL_A, LVL_B, and LVL_C: Input Level Registers (MODE=0Dh) Each register bit determines the voltage levels sensed on the input port, either TTL or CMOS, when the Schmitt trigger option is disabled. Program each bit according to the type of device that is driving the port input pin. Set the bit to 1 for TTL or clear the bit to 0 for CMOS. CMP_B: Comparator Register (MODE=08h) Each register bit determines whether the port input pin operates with a Schmitt trigger. Set the bit to 1 to disable Schmitt trigger operation and sense either TTL or CMOS voltage levels; or clear the bit to 0 to enable Schmitt trigger operation. When you access the CMP_B register using MOV !RB,W, the CPU does an exchange between the contents of W and CMP_B. This feature lets you read the CMP_B register contents. Clear bit 7 to enable operation of the comparator. Clear bit 6 to place the comparator result on the RB0 pin. Bit 0 is a result bit that is set to 1 when the voltage on RB2 is greater than RB1, or cleared to 0 otherwise. (For more information using the comparator, see Section 11.0.) WKEN_B: Wakeup Enable Register (MODE=0Bh) 3.2.3 Port Configuration Upon Reset Each register bit enables or disables the Multi-Input Wakeup/Interrupt (MIWU) function for the corresponding Port B input pin. Clear the bit to 0 to enable MIWU operation or set the bit to 1 to disable MIWU operation. For more information on using the Multi-Input Wakeup/Interrupt function, see Section 7.0. Upon reset, all the port control registers are initialized to FFh. Thus, each pin is configured to operate as a highimpedance input that senses TTL voltage levels, with no internal pullup resistor connected. The MODE register is initialized to 0Fh, which allows immediate access to the data direction registers using the "MOV !rx,W" instruction. ST_B and ST_C: Schmitt Trigger Enable Registers (MODE=0Ch) WKED_B: Wakeup Edge Register (MODE=0Ah) Each register bit selects the edge sensitivity of the Port B input pin for MIWU operation. Clear the bit to 0 to sense rising (low-to-high) edges. Set the bit to 1 to sense falling (high-to-low) edges. (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 10 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 4.0 SPECIAL-FUNCTION REGISTERS The CPU uses a set of special-function registers to control the operation of the device. the STATUS register with a result that is different than intended. The CPU registers include an 8-bit working register (W), which serves as a pseudo accumulator. It holds the second operand of an instruction, receives the literal in immediate type instructions, and also can be programselected as the destination register. A set of 31 file registers serves as the primary accumulator. One of these registers holds the first operand of an instruction and another can be program-selected as the destination register. The first eight file registers include the Real-Time Clock/Counter register (RTCC), the lower eight bits of the 11-bit Program Counter (PC), the 8-bit STATUS register, three port control registers for Port A, Port B, Port C, the 8-bit File Select Register (FSR), and INDF used for indirect addressing. The five low-order bits of the FSR register select one of the 31 file registers in the indirect addressing mode. Calling for the file register located at address 00h (INDF) in any of the file-oriented instructions selects indirect addressing, which uses the FSR register. It should be noted that the file register at address 00h is not a physically implemented register. The CPU also contains an 8level, 11-bit hardware push/pop stack for subroutine linkage. Table 4-1. Special-Function Registers Addr Name Function 00h INDF Used for indirect addressing 01h RTCC Real Time Clock/Counter 02h PC Program Counter (low byte) 03h STATUS Holds Status bits of ALU 04h FSR File Select Register 05h RA Port RA Control register 06h RB Port RB Control register 07h RC* Port RC Control register PC Register (02h) The PC register holds the lower eight bits of the program counter. It is accessible at run time to perform branch operations. 4.2 STATUS Register (03h) The STATUS register holds the arithmetic status of the ALU, the page select bits, and the reset state. The STATUS register is accessible during run time, except that bits PD and TO are read-only. It is recommended that only SETB and CLRB instructions be used on this register. Care should be exercised when writing to the STATUS register as the ALU status bits are updated upon completion of the write operation, possibly leaving (c) 2000 Scenix Semiconductor, Inc. All rights reserved. Bit 7 PA1 PA0 TO PD Z DC C Bit 0 Bit 7-5: Page select bits PA2:PA0 000 = Page 0 (000h - 01FFh) 001 = Page 1 (200h - 03FFh) 010 = Page 2 (400h - 05FFh) 011 = Page 3 (600h - 07FFh) Bit 4: Time Out bit, TO 1 = Set to 1 after power up and upon execution of CLRWDT or SLEEP instructions 0 = A watchdog time-out occurred Bit 3: Power Down bit, PD 1= Set to a 1 after power up and upon execution of the CLRWDT instruction 0 = Cleared to a `0' upon execution of SLEEP instruction Bit 2: Zero bit, Z 1 = Result of math operation is zero 0 = Result of math operation is non-zero Bit 1: Digit Carry bit, DC After Addition: 1 = A carry from bit 3 occurred 0 = No carry from bit 3 occurred After Subtraction: 1 = No borrow from bit 3 occurred 0 = A borrow from bit 3 occurred Bit 0: Carry bit, C After Addition: 1 = A carry from bit 7 of the result occurred *In the SX18 package, Port C is not used, and address 07h is available as a general-purpose RAM location. 4.1 PA2 - 11 - 0 = No carry from bit 7 of the result occurred After Subtraction: 1 = No borrow from bit 7 of the result occurred 0 = A borrow from bit 7 of the result occurred Rotate (RR or RL) Instructions: The carry bit is loaded with the low or high order bit, respectively. When CF bit is cleared, Carry bit works as input for ADD and SUB instructions. www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 4.3 OPTION Register Table 4-2. Prescaler Divider Ratios RTW RTE _IE RTS RTE _ES PSA PS2 PS1 Bit 7 PS0 PS2, PS1, PS0 Bit 0 When the OPTIONX bit in the FUSE word is cleared, bits 7 and 6 of the OPTION register function as described below. When the OPTIONX bit is set, bits 7 and 6 of the OPTION register read as `1's. RTW RTE_IE RTS RTE_ES PSA PS2-PS0 RTCC/W register selection: 0 = Register 01h addresses W 1 = Register 01h addresses RTCC RTCC edge interrupt enable: 0 = RTCC roll-over interrupt is enabled 1 = RTCC roll-over interrupt is disabled RTCC increment select: 0 = RTCC increments on internal instruction cycle 1 = RTCC increments upon transition on RTCC pin RTCC edge select: 0 = RTCC increments on low-to-high transitions 1 = RTCC increments on high-to-low transitions Prescaler Assignment: 0 = Prescaler is assigned to RTCC, with divide rate determined by PS0-PS2 bits 1 = Prescaler is assigned to WDT, and divide rate on RTCC is 1:1 Prescaler divider (see Table 4-2) (c) 2000 Scenix Semiconductor, Inc. All rights reserved. RTCC Divide Rate Watchdog Timer Divide Rate 000 1:2 1:1 001 1:4 1:2 010 1:8 1:4 011 1:16 1:8 100 1:32 1:16 101 1:64 1:32 110 1:128 1:64 111 1:256 1:128 Upon reset, all bits in the OPTION register are set to 1. - 12 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 5.0 DEVICE CONFIGURATION REGISTERS The SX device has three registers (FUSE, FUSEX, DEVICE) that control functions such as operating the device in Turbo mode, extended (8-level deep) stack operation, and speed selection for the internal RC oscillator. These registers are not programmable "on the fly" 5.1 during normal device operation. Instead, the FUSE and FUSEX registers can only be accessed when the SX device is being programmed. The DEVICE register is a read-only, hard-wired register, programmed during the manufacturing process. FUSE Word (Read/Program at FFFh in main memory map) TURBO SYNC Reserved Reserved IRC DIV1/ IFBD Bit 11 DIV0/ FOSC2 Reserved CP WDTE FOSC1 FOSC0 Bit 0 TURBO Turbo mode enable: 0= turbo (instruction clock = osc/1) 1= instr clock = osc/4 SYNC Synchronous input enable (for turbo mode): This bit synchronizes the signal presented at the input pin to the internal clock through two internal flip-flops. 0= enabled 1= disabled IRC Internal RC oscillator enable: 0= enabled - OSC1 pulled low by weak pullup, OSC2 pulled high by weak pullup 1= disabled - OSC1 and OSC2 behave according to FOSC2: FOSC0 DIV1: DIV0 Internal RC oscillator divider: 00b = 4 MHz 01b = 1 MHz 10 = 128 KHz 11b = 32 KHz IFBD Internal crystal/resonator oscillator feedback resistor: 0= disabled Internal feedback resistor disable (external feedback required) 1= enabled Internal feedback resistor enabled (valid when IRC = 1) CP Code protect enable: 0= enabled (FUSE, code, and ID memories read back as garbled data) 1= disabled (FUSE, code, and ID memories can be read normally) WDTE Watchdog timer enable: 0= disabled 1= enabled FOSC2: FOSC0 External oscillator configuration (valid when IRC = 1): 000b = LP1 - low power crystal (32KHz) 001b = LP2 - low power crystal/resonator (32 KHz to 1 MHz) 010b = XT1 - normal crystal/resonator (32 KHz to 10 MHz) 011b = XT2 - normal crystal/resonator (1MHz to 24 MHz) 100b = HS1 - high speed crystal/resonator (1MHz to 50 MHz) 101b = HS2 - high speed crystal/resonator (1 MHz to 50 MHz) 110b = HS3 - high speed crystal/resonator (1 MHz to 50 MHz) 111b = RC network - OSC2 is pulled high with a weak pullup (no CLKOUT output) Note: The frequencies are target values. (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 13 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 5.2 FUSEX Word (Read/Program via Programming Command) IRCTRIM2 PINS IRCTRIM1 OPTIONX/ STACKX IRCTRIM0 CF BOR1 BOR0 BORTRIM1 BORTRIM0 Bit 11 IRCTRIM2: IRCTRIM0 BP1 BP0 Bit 0 Internal RC oscillator trim bits. This 3-bit field adjusts the operation of the internal RC oscillator to make it operate within the target frequency range 4 MHz plus or minus 8%. Parts are shipped from the factory untrimmed. The device relies on the programming toll to provide the trimming function. 000b = minimum frequency 111b = maximum frequency each step about 3% Selects the number of pins. PINS 0 = 18/20 pins 0 = 28 pins OPTION Register Extension and Stack Extension. Set to 1 to disable the programmability of bit 6 and OPTIONX/ bit 7 in the OPTION register, the RTW and RTE_IE bits (in other words, to force these two bits to 1) and STACKX to limit the program stack size to two locations. Clear to 0 to enable programming of the RTW and RTE_IE bits in the OPTION register, and to extend the stack size to eight locations. CF active low - makes carry bit input to ADD and SUB instructions. BOR1: BOR0 Brown-Out Reset;These bits enable or disable the brown-out reset function and set the brown-out threshold voltage as follows: 00b = 4.2V 01b = 2.6V 10b = 2.2V BORTRIM1: BORTRIM2 BP1:BP0 5.3 11b = Brown-Out disabled Brown-Out trim bits (parts are shipped out of factory untrimmed). Configure Memory Size: 00b = 1 page, 1 bank 01b = 1 page, 2 banks 10b = 4 pages, 4 banks 11b = 4 pages, 8 banks (default configuration) DEVICE Word (Hard-Wired Read-Only) 1 1 1 1 1 1 0 Bit 11 (c) 2000 Scenix Semiconductor, Inc. All rights reserved. 0 1 1 1 0 Bit 0 - 14 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 6.0 MEMORY ORGANIZATION 6.1 Program Memory 6.2 Data Memory The program memory is organized as 2K, 12-bit wide words. The program memory words are addressed sequentially by a binary program counter. The program counter starts at zero. If there is no branch operation, it will increment to the maximum value possible for the device and roll over and begin again. The data memory consists of 136 bytes of RAM, organized as eight banks of 16 registers plus eight registers which are not banked. Both banked and non-banked memory locations can be addressed directly or indirectly using the FSR (File Select Register). The special-function registers are mapped into the data memory. Internally, the program memory has a semi-transparent page structure. A page is composed of 512 contiguous program memory words. The lower nine bits of the program counter are zeros at the first address of a page and ones at the last address of a page. This page structure has no effect on the program counter. The program counter will freely increment through the page boundaries. 6.2.1 File Select Register (04h) 6.1.1 Program Counter The program counter contains the 11-bit address of the instruction to be executed. The lower eight bits of the program counter are contained in the PC register (02h) while the upper bits come from the upper three bits of the STATUS register (PA0, PA1, PA2). This is necessary to cause jumps and subroutine calls across program memory page boundaries. Prior to the execution of a branch operation, the user program must initialize the upper bits of the STATUS register to cause a branch to the desired page. An alternative method is to use the PAGE instruction, which automatically causes branch to the desired page, based on the value specified in the operand field. Upon reset, the program counter is initialized with 07FFh. 6.1.2 Subroutine Stack The subroutine stack consists of eight 11-bit save registers. A physical transfer of register contents from the program counter to the stack or vice versa, and within the stack, occurs on all operations affecting the stack, primarily calls and returns. The stack is physically and logically separate from data RAM. The program cannot read or write the stack. (c) 2000 Scenix Semiconductor, Inc. All rights reserved. Instructions that specify a register as the operand can only express five bits of register address. This means that only registers 00h to 1Fh can be accessed. The File Select Register (FSR) provides the ability to access registers beyond 1Fh. Figure 6-1 shows how FSR can be used to address RAM locations. The three high-order bits of FSR select one of eight SRAM banks to be accessed. The five low-order bits select one of 32 SRAM locations within the selected bank. For the lower 16 addresses, Bank 0 is always accessed, irrespective of the three high-order bits. Thus, RAM register addresses 00h through 0Fh are "global" in that they can always be accessed, regardless of the contents of the FSR. The entire data memory (including the dedicated-function registers) consists of the lower 16 bytes of Bank 0 and the upper 16 bytes of Bank 0 through Bank 7, for a total of (1+8)*16 = 144 bytes. Eight of these bytes are for the function registers, leaving 136 general-purpose memory locations. In the 18-pin SX packages, register RC is not used, which makes address 07h available as an additional general-purpose memory location. Below is an example of how to write to register 10h in Bank 4: - 15 - mov FSR,#$90 mov $10,#$64 ;Select Bank 4 by ;setting FSR<7:5> ;load register 10h with ;the literal 64h www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 Function Registers Bank 0 Bank 0 is always accessed for the lower 16 addresses, irrespective of the three highorder bits of FSR. 00 INDF Registers (8 bytes) RTCC PC 07 STATUS SRAM (8 bytes) FSR RA 0F RB 7 RC 6 1 0 FSR B0 Bank 5 90 Bank 4 70 Bank 3 Bank 1 2 D0 Bank 6 50 Bank 2 3 F0 Bank 7 10 5 4 FF 30 DF Bank 0 BF 9F SRAM (16 bytes each bank 128 bytes total) 7F 5F 3F 111 110 101 100 011 010 001 000 1F Figure 6-1. Data Memory Organization (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 16 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 7.0 POWER DOWN MODE The power down mode is entered by executing the SLEEP instruction. feature. The WKEN_B register (Wakeup Enable Register) allows any Port B pin or combination of pins to cause the wakeup. Clearing a bit in the WKEN_B register enables the wakeup on the corresponding Port B pin. If multi-input wakeup is selected to cause a wakeup, the trigger condition on the selected pin can be either rising edge (low to high) or falling edge (high to low). The WKED_B register (Wakeup Edge Select) selects the desired transition edge. Setting a bit in the WKED_B register selects the falling edge on the corresponding Port B. Clearing the bit selects the rising edge. The WKEN_B and WKED_B registers are set to FFh upon reset. In power down mode, only the Watchdog Timer (WDT) is active. If the Watchdog Timer is enabled, upon execution of the SLEEP instruction, the Watchdog Timer is cleared, the TO (time out) bit is set in the STATUS register, and the PD (power down) bit is cleared in the STATUS register. There are three different ways to exit from the power down mode: a timer overflow signal from the Watchdog Timer (WDT), a valid transition on any of the Multi-Input Wakeup pins (Port B pins), or through an external reset input on the MCLR pin. Once a valid transition occurs on the selected pin, the WKPND_B register (Wakeup Pending Register) latches the transition in the corresponding bit position. A logic `1' indicates the occurrence of the selected trigger edge on the corresponding Port B pin. To achieve the lowest possible power consumption, the Watchdog Timer should be disabled and the device should exit the power down mode through the Multi-Input Wakeup (MIWU) pins or an external reset. 7.1 Upon exiting the power down mode, the Multi-Input Wakeup logic causes program counter to branch to the maximum program memory address (same as reset). Multi-Input Wakeup Multi-Input Wakeup is one way of causing the device to exit the power down mode. Port B is used to support this RB7 Figure 7-1 shows the Multi-Input Wakeup block diagram. RB6 RB1 RB0 Port B Configured as Input 8 W MODE = 0B Internal Data Bus MODE 8 MODE = 0A WKED_B 0 1 WKPND_B MODE = 09 Wake-up : Exit Power Down WKEN_B 0 = Enable 1 = Disable 8 Figure 7-1. Multi-Input Wakeup Block Diagram (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 17 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 7.2 Port B MIWU/Interrupt Configuration The WKPND_B register comes up with a random value upon reset. The user program must clear the register prior to enabling the wake-up condition or interrupts. The proper initialization sequence is: Here is an example of a program segment that configures the RB0, RB1, and RB2 pins to operate as MultiInput Wakeup/Interrupt pins, sensitive to falling edges: mov M,#$0F 1. Select the desired edge (through WKED_B register). 2. Clear the WKPND_B register. 3. Enable the Wakeup condition (through WKEN_B register). Below is an example of how to read the WKPND_B register to determine which Port B pin caused the wakeup or interrupt, and to clear the WKPND_B register: mov clr mov M,#$09 W !RB,W mov W,#$07 mov !RB,W mov M,#$0A mov !RB,W mov M,#$09 mov W,#$00 mov !RB,W ;W contains WKPND_B ;contents of W exchanged ;with contents of WKPND_B ;prepare to write port data ;direction registers ;load W with the value 07h ;configure RB0-RB2 to be inputs ;prepare to write WKED_B ;(edge) register ;W contains the value 07h ;configure RB0-RB2 to sense ;falling edges ;prepare to access WKPND_B ;(pending) register ;clear W ;clear all wakeup pending bits mov M,#$0B The final "mov" instruction in this example performs an exchange of data between the working register (W) and the WKPND_B register. This exchange occurs only with Port B accesses. Otherwise, the "mov" instruction does not perform an exchange, but only moves data from the source to the destination. (c) 2000 Scenix Semiconductor, Inc. All rights reserved. ;prepare to write WKEN_B (enable) ;register mov W,#$F8h ;load W with the value F8h mov !RB,W ;enable RB0-RB2 to operate as ;wakeup inputs To prevent false interrupts, the enabling step (clearing bits in WKEN_B) should be done as the last step in a sequence of Port B configuration steps. After this program segment is executed, the device can receive interrupts on the RB0, RB1, and RB2 pins. If the device is put into the power down mode (by executing the SLEEP instruction), the device can then receive wakeup signals on those same pins. - 18 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 8.0 INTERRUPT SUPPORT The device supports both internal and external maskable interrupts. The internal interrupt is generated as a result of the RTCC rolling over from 0FFh to 00h. This interrupt source has an associated enable bit located in the OPTION register. There is no pending bit associated with this interrupt. Port B provides the source for eight external software selectable, edge sensitive interrupts. These interrupt sources share logic with the Multi-Input Wakeup circuitry. The WKEN_B register allows interrupt from Port B to be individually enabled or disabled. Clearing a bit in the WKEN_B register enables the interrupt on the corresponding Port B pin. The WKED_B selects the transition edge to be either positive or negative. The WKEN_B and WKED_B registers are set to FFh upon reset. Setting a bit in the WKED_B register selects the falling edge while clearing the bit selects the rising edge on the corresponding Port B pin. The WKPND_B register serves as the external interrupt pending register. The WKPND_B register comes up a with random value upon reset. The user program must clear the WKPND_B register prior to enabling the interrupt. The proper sequence is described in Section 7.2 . Figure 8-1 shows the structure of the interrupt logic. Port B PIN WKED_B WKED_B RTCC Overflow In te rn a l D a ta B u s From MODE (MODE = 0A) WKPND_B WKPND_B STATUS Register PD bit From MODE (MODE = 09) Interrupt 1 = Ext. Interrupt through Port B 0 = Power Down Mode, no Ext. Interrupt PC 000 Interrupt Stack PC RTE_IE OPTION WKEN_B Figure 8-1. Interrupt Structure (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 19 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 All interrupts are global in nature; that is, no interrupt has priority over another. Interrupts are handled sequentially. Figure 8-2 shows the interrupt processing sequence. Once an interrupt is acknowledged, all subsequent global interrupts are disabled until return from servicing the current interrupt. The PC is pushed onto the single level interrupt stack, and the contents of the FSR, STATUS, and W registers are saved in their corresponding shadow registers. The status bits PA0, PA1, and PA2 bits are cleared after the STATUS register has been saved in its shadow register. The interrupt logic has its own singlelevel stack and is not part of the CALL subroutine stack. The vector for the interrupt service routine is address 0. Once in the interrupt service routine, the user program must check all external interrupt pending bits (contained in the WKPND_B register) to determine the source of the interrupt. The interrupt service routine should clear the corresponding interrupt pending bit. If both internal and external interrupts are enabled, the user program may also need to read the contents of RTCC to determine any recent RTCC rollover. This is needed since there is no interrupt pending bit associated with the RTCC rollover. Normally it is a requirement for the user program to process every interrupt without missing any. To ensure this, the longest path through the interrupt routine must take less time than the shortest possible delay between interrupts. If an external interrupt occurs during the interrupt routine, the pending register will be updated but the trigger will be ignored unless interrupts are disabled at the beginning of the interrupt routine and enabled again at the end. This also requires that the new interrupt does not occur before interrupts are disabled in the interrupt routine. If there is a possibility of additional interrupts occurring before they can be disabled, the device will miss those interrupt triggers. In other words, using more than one interrupt, such as multiple external interrupts or both RTCC and external interrupts, can result in missed or, at best, jittery interrupt handling should one occur during the processing of another. When handling external interrupts, the interrupt routine should clear at least one pending register bit. The bit that is cleared should represent the interrupt being handled in order for the next interrupt to trigger. Upon return from the interrupt service routine, the contents of PC, FSR, STATUS, and W registers are restored from their corresponding shadow registers. The interrupt service routine should end with instructions such as RETI and RETIW. RETI pops the interrupt stack and the special shadow registers used for storing W, STATUS, and FSR (preserved during interrupt handling). RETIW behaves like RETI but also adds W to RTCC. The interrupt return instruction enables the global interrupts. Program Memory Address 000h Interrupt Service Routine PC RETI Interrupt Stack Interrupt Stack 000h PC PC W Register W Shadow Register W Register W Shadow Register STATUS Register STATUS Shadow Register STATUS Register STATUS Shadow Register FSR Register FSR Shadow Register FSR Register FSR Shadow Register Note: The interrupt logic has its own single-level stack and is not part of the CALL subroutine stack. Figure 8-2. Interrupt Processing (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 20 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 9.0 OSCILLATOR CIRCUITS SX Device The device supports several user-selectable oscillator modes. The oscillator modes are selected by programming the appropriate values into the FUSE Word register. These are the different oscillator modes offered: LP: XT: HS: RC: 9.1 Internal Circuitry SLEEP Low Power Crystal Crystal/Resonator High Speed Crystal/Resonator External Resistor/Capacitor Internal Resistor/Capacitor OSC1 OSC2 RF XT, LP or HS modes RS XTAL In XT, LP or HS, modes, you can use either an external resonator network or an external clock signal as the device clock. C2 C1 To use an external resonator network, you connect a crystal or ceramic resonator to the OSC1/CLKIN and OSC2/CLKOUT pins according to the circuit configuration shown in Figure 9-1. A parallel resonant crystal type is recommended. Use of a series resonant crystal may result in a frequency that is outside the crystal manufacturer specifications. Table 9-1 shows the recommended external components associated with a crystal-based oscillator. Table 9-2 shows the recommended external component values for a resonator-based oscillator. Figure 9-1. Crystal Operation (or Ceramic Resonator) (HS, XT or LP OSC Configuration) SX Device Bits 0, 1 and 5 of the FUSE register (FOSC1:FOSC2) are used to configure the different external resonator/crystal oscillator modes. These bits allow the selection of the appropriate gain setting for the internal driver to match the desired operating frequency. If the XT, LP, or HS mode is selected, the OSC1/CLKIN pin can be driven by an external clock source rather than a resonator network, as long as the clock signal meets the specified duty cycle, rise and fall times, and input levels (Figure 9-2). In this case, the OSC2/CLKOUT pin should be left open. OSC2 OSC1 Open Externally Generated Clock Figure 9-2. External Clock Input Operation (HS, XT or LP OSC Configuration) Table 9-1. External Component Selection for Crystal Oscillator(Vdd=5.0V) FOSC2:FOSC0 Crystal Frequency C1 C2 RF RS 010 4 MHz 15 pF 22 pF 1 M 0 011 8 MHz 56 pF 33 pF 1 M 0 011 20 MHz 33 pF 22 pF 1 M 0 011 32 MHz 15 pF 22 pF 1 M 0 100 50* MHz 15 pF 15 pF 1 M 0 * 50 MHz fundamental crystal (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 21 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 Table 9-2. External Component Selection for Murata Ceramic Resonators (Vdd=5.0V) FOSC2:FOSC0 Resonator Frequency Resonator Part Number C1 C2 RF RS 011 4 MHz CSA4.00MG 30 pF 30 pF 1M 0 011 4 MHz CST4.00MGW Internal (30 pF) Internal (30 pF) 1 M 0 011 4 MHz CSTCC4.00G0H6 Internal (47 pF) Internal (47 pF) 1 M 0 011 8 MHz CSA8.00MTZ 30 pF 30 pF 1 M 0 011 8 MHz CST8.00MTW Internal (30 pF) Internal 30 pF) 1 M 0 011 8 MHz CSTCC8.00MG0H6 Internal (47 pF) Internal 47pF) 1 M 0 011 20 MHz CSA20.00MXZ040 5 pF 5 pF 1 M 0 011 20 MHz CST20.00MXW0H1 Internal (5 pF) Internal (5 pF) 1 M 0 011 20 MHz CSACV20.00MXJ040 5 pF 5 pF 22 k 0 011 20 MHz CSTCV20.00MXJ0H1 Internal (5 pF) Internal (5 pF) 22 k 0 100 33 MHz CSA33.00MXJ040 5 pF 5 pF 1 M 0 100 33 MHz CST33.00MXW040 Internal (5 pF) Internal (5 pF) 1 M 0 100 33 MHz CSACV33.00MXJ040 5 pF 5 pF 1 M 0 100 33 MHz CSTCV33.00MXJ040 Internal (5 pF) Internal (5 pF) 1 M 0 101 50 MHz CSA50.00MXZ040 15 pF 15 pF 10 k 0 101 50 MHz CST50.00MXW0H3 Internal (15 pF) Internal (15 pF) 10 k 0 101 50 MHz CSACV50.00MXJ040 15 pF 15 pF 10 k 0 101 50 MHz CSTCV50.00MXJ0H3 Internal (15 pF) Internal (15 pF) 10 k 0 (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 22 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 9.2 External RC Mode 9.3 The external RC oscillator mode provides a cost-effective approach for applications that do not require a precise operating frequency. In this mode, the RC oscillator frequency is a function of the supply voltage, the resistor (R) and capacitor (C) values, and the operating temperature. In addition, the oscillator frequency will vary from unit to unit due to normal manufacturing process variations. Furthermore, the difference in lead frame capacitance between package types also affects the oscillation frequency, especially for low C values. The external R and C component tolerances contribute to oscillator frequency variation as well. Figure 9-3 shows the external RC connection diagram. The recommended R value is from 3k to 100k. For R values below 2.2k, the oscillator may become unstable, or may stop completely. For very high R values (such as 1 M), the oscillator becomes sensitive to noise, humidity, and leakage. Although the oscillator will operate with no external capacitor (C = 0pF), it is recommended that you use values above 20 pF for noise immunity and stability. With no or small external capacitance, the oscillation frequency can vary significantly due to variation in PCB trace or package lead frame capacitances. Internal RC Mode The internal RC mode uses an internal oscillator, so the device does not need any external components. At 4 MHz, the internal oscillator provides typically +/-8% accuracy over the allowed temperature range. The internal clock frequency can be divided down to provide one of eight lower-frequency choices by selecting the desired value in the FUSE Word register. The frequency range is from 31.25 KHz to 4 MHz. The default operating frequency of the internal RC oscillator may not be 4 MHz. This is due to the fact that the SX device requires trimming to obtain 4 MHz operation. The parts shipped out of the factory are not trimmed. The device relies on the programming tool provided by the third party vendors to support trimming. 10.0 REAL TIME CLOCK (RTCC)/WATCHDOG TIMER The device contains an 8-bit Real Time Clock/Counter (RTCC) and an 8-bit Watchdog Timer (WDT). An 8-bit programmable prescaler extends the RTCC to 16 bits. If the prescaler is not used for the RTCC, it can serve as a postscaler for the Watchdog Timer. Figure 10-1 shows the RTCC and WDT block diagram. 10.1 RTCC RTCC is an 8-bit real-time timer that is incremented once each instruction cycle or from a transition on the RTCC pin. The on-board prescaler can be used to extend the RTCC counter to 16 bits. SX Device ~ Internal Circuitry To select the internal clock source, bit 5 of the OPTION register should be cleared. In this mode, RTCC is incremented at each instruction cycle unless the prescaler is selected to increment the counter. N OSC1 Vdd The RTCC counter can be clocked by the internal instruction cycle clock or by an external clock source presented at the RTCC pin. OSC2 R C Figure 9-3. RC Oscillator Mode (c) 2000 Scenix Semiconductor, Inc. All rights reserved. To select the external clock source, bit 5 of the OPTION register must be set. In this mode, the RTCC counter is incremented with each valid signal transition at the RTTC pin. By using bit 4 of the OPTION register, the transition can be programmed to be either a falling edge or rising edge. Setting the control bit selects the falling edge to increment the counter. Clearing the bit selects the rising edge. The RTCC generates an interrupt as a result of an RTCC rollover from 0FF to 000. There is no interrupt pending bit to indicate the overflow occurrence. The RTCC register must be sampled by the program to determine any overflow occurrence. - 23 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 10.2 Watchdog Timer The watchdog logic consists of a Watchdog Timer which shares the same 8-bit programmable prescaler with the RTCC. The prescaler actually serves as a postscaler if used in conjunction with the WDT, in contrast to its use as a prescaler with the RTCC. WDTE (from FUSE Word) WDT M U X 10.3 The Prescaler The 8-bit prescaler may be assigned to either the RTCC or the WDT through the PSA bit (bit 3 of the OPTION register). Setting the PSA bit assigns the prescaler to the WDT. If assigned to the WDT, the WDT clocks the prescaler and the prescaler divide rate is selected by the PS0, PS1, and PS2 bits located in the OPTION register. Clearing the PSA bit assigns the prescaler to the RTCC. Once assigned to the RTCC, the prescaler clocks the RTCC and the divide rate is selected by the PS0, PS1, and PS2 bits in the OPTION register. The prescaler is not mapped into the data memory, so run-time access is not possible. The prescaler cannot be assigned to both the RTCC and WDT simultaneously. RTCC Interrupt Enable FOSC RTCC pin MUX 8-Bit Prescaler RTW RTE_IE RST RTE_ES PSA PS2 PS1 PS0 OPTION Register MUX (8 to 1) M U X RTCC Rollover Interrupt RTCC MUX 8-Bits WDT Time-out Data Bus Figure 10-1. RTCC and WDT Block Diagram (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 24 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 11.0 COMPARATOR The device contains an on-chip differential comparator. Ports RB0-RB2 support the comparator. Ports RB1 and RB2 are the comparator negative and positive inputs, respectively, while Port RB0 serves as the comparator output pin. To use these pins in conjunction with the comparator, the user program must configure Ports RB1 and RB2 as inputs and Port RB0 as an output. The CMP_B register is used to enable the comparator, to read the output of the comparator internally, and to enable the output of the comparator to the comparator output pin. The comparator enable bits are set to "1" upon reset, thus disabling the comparator. To avoid drawing additional current during the power down mode, the comparator should be disabled before entering the power down mode. Here is an example of how to setup the comparator and read the CMP_B register. mov M,#$08 ;set MODE register to access ;CMP_B mov W,#$00 ;clear W mov !RB,W ;enable comparator and its ;output ... ;delay after enabling ;comparator for response mov M,#$08 ;set MODE register to access ;CMP_B mov W,#$00 ;clear W mov !RB,W ;enable comparator and its ;output and also read CMP_B ;(exchange W and CMB_B) and W,#$01 ;set/clear Z bit based on ;comparator result snb $03.2 ;test Z bit in STATUS reg ;(0 => RB2<RB1) jmp rb2_hi ;jump only if RB2>RB1 The final "mov" instruction in this example performs an exchange of data between the working register (W) and the CMP_B register. This exchange occurs only with Port B accesses. Otherwise, the "mov" instruction does not perform an exchange, but only moves data from the source to the destination. Figure 11-1 shows the comparator block diagram. CMP_B - Comparator Enable/Status Register CMP_EN CMP_OE Reserved CMP_RES Bit 7 Bit 6 Bits 5-1 Bit 0 CMP_RES CMP_OE CMP_EN Comparator result: 1 for RB2>RB1 or 0 for RB2<RB1. Comparator must be enabled (CMP_EN = 0) to read the result. The result can be read whether or not the CMP_OE bit is cleared. When cleared to 0, enables the comparator output to the RB0 pin. When cleared to 0, enables the comparator. ... (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 25 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 Internal Data Bus CMP_B CMP_EN 7 CMP_OE 6 W RB0 RB1 RB2 R E S E R V E D + CMP_RES MODE MODE = 08h 0 Point to CMP_B Figure 11-1. Comparator Block Diagram (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 26 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 12.0 RESET Power-On-Reset, Brown-Out reset, watchdog reset, or external reset initializes the device. Each one of these reset conditions causes the program counter to branch to the top of the program memory. For example, on the device with 2048K words of program memory, the program counter is initialized to 07FF. The device incorporates an on-chip Power-On Reset (POR) circuit that generates an internal reset as V dd rises during power-up. Figure 12-1 is a block diagram of the circuit. The circuit contains an 10-bit Delay Reset Timer (DRT) and a reset latch. The DRT controls the reset timeout delay. The reset latch controls the internal reset signal. Upon power-up, the reset latch is set (device held in reset), and the DRT starts counting once it detects a valid logic high signal at the MCLR pin. Once DRT reaches the end of the timeout period (typically 72 msec), the reset latch is cleared, releasing the device from reset state. Figure 12-2 shows a power-up sequence where MCLR is not tied to the Vdd pin and Vdd signal is allowed to rise and stabilize before MCLR pin is brought high. The device will actually come out of reset Tdrt msec after MCLR goes high. The brown-out circuitry resets the chip when device power (Vdd) dips below its minimum allowed value, but not to zero, and then recovers to the normal value. . Vdd MCLR POR Tdrt drt_time_out MIWU POR Vdd RESET POR Figure 12-2. Time-Out Sequence on Power-Up (MCLR not tied to Vdd) BROWN-OUT MCLR/Vpp pin wdt_time_out enable rc_clk 10-Bit Asynch S Ripple Counter (DRT Start-Up R Timer) drt_time _out Q RESET QN Note:Ripple counter is 10 bits for Power on Reset (POR) only. Figure 12-1. Block Diagram of On-Chip Reset Circuit (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 27 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 Figure 12-3 shows the on-chip Power-On Reset sequence where the MCLR and Vdd pins are tied together. The Vdd signal is stable before the DRT timeout period expires. In this case, the device will receive a proper reset. However, Figure 12-4 depicts a situation where Vdd rises too slowly. In this scenario, the DRT will time-out prior to Vdd reaching a valid operating voltage level (Vdd min). This means the device will come out of reset and start operating with the supply voltage not at a valid level. In this situation, it is recommended that you use the external RC circuit shown in Figure 12-5. The RC delay should exceed the time period it takes Vdd to reach a valid operating voltage Vdd D R R1 MCLR C Figure 12-5. External Power-On Reset Circuit (For Slow Vdd Power-up) Note 1: The external Power-On Reset circuit is required only if Vdd power-up is too slow. The diode D helps discharge the capacitor quickly when Vdd powers down. Vdd Note 2: R < 40 k is recommended to make sure that voltage drop across R does not violate the device electrical specifications. MCLR POR Note 3: R1 = 100 to 1k will limit any current flowing into MCLR from external capacitor C. This helps prevent MCLR pin breakdown due to Electrostatic Discharge (ESD) or Electrical Overstress (EOS). Tdrt drt_time_out RESET Figure 12-3. Time-out Sequence on Power-up (MCLR tied to Vdd): Fast Vdd Rise Time V1 Vdd MCLR 13.0 BROWN-OUT DETECTOR The on-chip brown-out detection circuitry resets the device when Vdd dips below the specified brown-out voltage. The device is held in reset as long as Vdd stays below the brown-out voltage. The device will come out of reset when Vdd rises above the brown-out voltage. The brown-out level is preset to approximately 4.2V at the factory. The brown-out circuit can be disabled through BOR0 and BOR1 bits contained in the FUSEX Word register. POR Tdrt drt_time_out RESET Figure 12-4. Time-out Sequence on Power-up (MCLR tied to Vdd): Slow Rise Time (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 28 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 14.0 REGISTER STATES UPON DIFFERENT RESET OPERATIONS The effect of different reset operation on a register depends on the register and the type of reset operation. Some registers are initialized to specific values, some are left unchanged, some are undefined, and some are initialized to an unknown value. A register that starts with an unknown value should be initialized by the software to a known value; you cannot simply test the initial state and rely on it starting in that state consistently. Table 14-1 lists the SX registers and shows the state of each register upon different reset. Table 14-1. Register States Upon Different Resets Register Power-On Wakeup Brown-out Watchdog Timeout MCLR W Undefined Unchanged Undefined Unchanged Unchanged OPTION FFh FFh FFh FFh FFh MODE 0Fh 0Fh 0Fh 0Fh 0Fh RTCC (01h) Undefined Unchanged Undefined Unchanged Unchanged PC (02h) FFh FFh FFh FFh FFh STATUS (03h) Bits 0-2: Undefined Bits 0-2: Unchanged. Bits 0-4: Undefined Bits 0-2: Unchanged Bits 0-2: Unchanged Bits 3-4: 11 Bits 3-4: Unch. Bits 5-7: 000 Bits 3-4: (Note 1) Bits 3-4: (Note 2) Bits 5-7: 000 Bits 5-7: 000 Undefined Bits 0-6: Unchanged Bits 5-7: 000 Bits 5-7: 000 Bits 0-6: Undefined Bits 0-6: Unchanged Bits 0-6: Unchanged Bit 7: 1 Bit 7: 1 Bit 7: 1 Bit 7: 1 FFh FFh FFh FFh FFh RA/RB/RC Data Undefined Unchanged Undefined Unchanged Unchanged Other File Registers SRAM Undefined Unchanged Undefined Unchanged Unchanged CMP_B Bits 0, 6-7: 1 Bits 0, 6-7: 1 Bits 0, 6-7: 1 Bits 0, 6-7: 1 Bits 0, 6-7: 1 Bits 1-5: Undefined Bits 1-5: Undefined Bits 1-5: Undefined Bits 1-5: Undefined Bits 1-5: Undefined WKPND_B Undefined Unchanged Undefined Unchanged Unchanged WKED_B FFh FFh FFh FFh FFh WKEN_B FFh FFh FFh FFh FFh ST_B/ST_C FFh FFh FFh FFh FFh LVL_A/LVL_B/LVL_C FFh FFh FFh FFh FFh PLP_A/PLP_B/PLP_C FFh FFh FFh FFh FFh Watchdog Counter Undefined Unchanged Undefined Unchanged Unchanged FSR (04h) RA/RB/RC Direction NOTE: 1. Watchdog reset during power down mode: 00 (TO, PD) Watchdog reset during Active mode: 01 (TO, PD) NOTE: 2. External reset during power down mode: 10 (TO, PD) External reset during Active mode: Unchanged (TO, PD) (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 29 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 15.0 INSTRUCTION SET As mentioned earlier, the SX family of devices uses a modified Harvard architecture with memory-mapped input/output. The device also has a RISC type architecture in that there are 43 single-word basic instructions. The instruction set contains byte-oriented file register, bitoriented file register, and literal/control instructions. Working register W is one of the CPU registers, which serves as a pseudo accumulator. It is a pseudo accumulator in a sense that it holds the second operand, receives the literal in the immediate type instructions, and also can be program-selected as the destination register. The bank of 31 file registers can also serve as the primary accumulators, but they represent the first operand and may be program-selected as the destination registers. fetched. Once the pipeline is full, instructions are executed at the rate of one per clock cycle. Instructions that directly affect the contents of the program counter (such as jumps and calls) require that the pipeline be cleared and subsequently refilled. Therefore, these instruction take more than one clock cycle. The instruction execution time is derived by dividing the oscillator frequency by either one (turbo mode) or four (non-turbo mode). The divide-by factor is selected through the FUSE Word register. Fetch Decode Execute Write 15.1 Instruction Set Features 1. All single-word (12-bit) instructions for compact code efficiency. 2. All instructions are single cycle except the jump type instructions (JMP, CALL) and failed test instructions (DECSZ fr, INCSZ fr, SB bit, SNB bit), which are twocycle. 3. A set of File registers can be addressed directly or indirectly, and serve as accumulators to provide first operand; W register provides the second operand. 4. Many instructions include a destination bit which selects either the register file or the accumulator as the destination for the result. 5. Bit manipulation instructions (Set, Clear, Test and Skip if Set, Test and Skip if Clear). 6. STATUS Word register memory-mapped as a register file, allowing testing of status bits (carry, digit carry, zero, power down, and timeout). 7. Program Counter (PC) memory-mapped as register file allows W to be used as offset register for indirect addressing of program memory. 8. Indirect addressing data pointer FSR (file select register) memory-mapped as a register file. 9. IREAD instruction allows reading the instruction from the program memory addressed by W and upper four bits of MODE register. 10.Eight-level, 11-bit push/pop hardware stack for subroutine linkage using the Call and Return instructions. 11.Six addressing modes provide great flexibility. An instruction goes through a four-stage pipeline to be executed (Figure 15-1). The first instruction is fetched from the program memory on the first clock cycle. On the second clock cycle, the first instruction is decoded and the second instruction is fetched. On the third clock cycle, the first instruction is executed, the second instruction is decoded, and the third instruction is fetched. On the fourth clock cycle, the first instruction's results are written to its destination, the second instruction is executed, the third instruction is decoded, and the fourth instruction is Clock Cycle 2 Clock Cycle 3 Clock Cycle 4 Figure 15-1. Pipeline and Clock Scheme 15.3 Addressing Modes The device support the following addressing modes: Data Direct Data Indirect Immediate Program Direct Program Indirect Relative Both direct and indirect addressing modes are available. The INDF register, though physically not implemented, is used in conjunction with the indirect data pointer (FSR) to perform indirect addressing. An instruction using INDF as its operand field actually performs the operation on the register pointed by the contents of the FSR. Consequently, processing two multiple-byte operands requires alternate loading of the operand addresses into the FSR pointer as the multiple byte data fields are processed. Examples: Direct addressing: mov 15.2 Instruction Execution (c) 2000 Scenix Semiconductor, Inc. All rights reserved. Clock Cycle 1 RA,#01 ;move "1" to RA Indirect Addressing: - 30 - mov FSR,#RA ;FSR = address of RA mov INDF,#$01 ;move "1" to RA www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 15.4 RAM Addressing 15.6 Direct Addressing The FSR register must initialized with an appropriate value in order to address the desired RAM register. The following table and code example show how to directly access the banked registers. The instruction set contains instructions to set, reset, and test individual bits in data memory. The device is capable of bit addressing anywhere in data memory. Bank FSR Value 0 010h 1 030h 2 050h 3 070h 4 090h 5 0B0h 6 0D0h 7 0F0h mov clr FSR,#$070 $010 mov clr FSR,#$D0 $010 FSR :loop setb SFR.4 clr INDF incsz FSR jmp :loop ;Select RAM Bank 3 ;Clear register 10h on ;Bank 3 ;Select RAM Bank 6 ;Clear register 10h on ;Bank 6 15.8 15.10 Branch and Loop Call Instructions Often it is desirable to set the bank select bits of the FSR register in one instruction cycle. The Bank instruction provides this capability. This instruction sets the upper bits of the FSR to point to a specific RAM bank without affecting the other FSR bits. ;Select Bank 7 in FSR inc ;increment file register ;1Fh in Bank 7 $1F (c) 2000 Scenix Semiconductor, Inc. All rights reserved. Loop Counting and Data Pointing Testing The device has specific instructions to facilitate loop counting. The DECSZ fr (decrement file register and skip if zero) tests any one of the file registers and skips the next instruction (which can be a branch back to loop) if the result is zero. 15.5 The Bank Instruction bank $F0 Increment/Decrement The bank of 31 registers serves as a set of accumulators. The instruction set contains instructions to increment and decrement the register file. The device also includes both INCSZ fr (increment file register and skip if zero) and DECSZ fr (decrement file register and skip if zero) instructions. 15.9 ;clear FSR to 00h (at address ;04h) ;set bit 4: address 10h-1Fh, ;30-3Fh, etc ;clear register pointed to by ;FSR ;increment FSR and test, skip ;jmp if 00h ;jump back and clear next ;register Example: Input/Output Operation The device contains three registers associated with each I/O port. The first register (Data Direction Register), configures each port pin as a Hi-Z input or output. The second register (TTL/CMOS Register), selects the desired input level for the input. The third register (Pull-Up Register), enables a weak pull-up resistor on the pin configured as a input. In addition to using the associated port registers, appropriate values must be written into the MODE register to configure the I/O ports. When two successive read-modify-write instructions are used on the same I/O port with a very high clock rate, the "write" part of one instruction might not occur soon enough before the "read" part of the very next instruction, resulting in getting "old" data for the second instruction. To ensure predictable results, avoid using two successive read-modify-write instructions that access the same port data register if the clock rate is high. Indirect Addressing To access any register via indirect addressing, simply move the eight-bit address of the desired register into the FSR and use INDF as the operand. The example below shows how to clear all RAM locations from 10h to 1Fh in all eight banks: clr 15.7 Bit Manipulation The device contains an 8-level hardware stack where the return address is stored with a subroutine call. Multiple stack levels allow subroutine nesting. The instruction set supports absolute address branching. 15.10.1 Jump Operation When a JMP instruction is executed, the lower nine bits of the program counter is loaded with the address of the specified label. The upper two bits of the program counter are loaded with the page select bits, PA1:PA0, contained in the STATUS register. Therefore, care must be exercised to ensure the page select bits are pointing to the correct page before the jump occurs. - 31 - STATUS<6:5> JMP LABEL PC<10:9> PC<8:0> www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 15.10.2 Page Jump Operation 15.10.4 Page Call Operation When a JMP instruction is executed and the intended destination is on a different page, the page select bits must be initialized with appropriate values to point to the desired page before the jump occurs. This can be done easily with SETB and CLRB instructions or by writing a value to the STATUS register. The device also has the PAGE instruction, which automatically selects the page in a single-cycle execution. When a subroutine that resides on a different page is called, the page select bits must contain the proper values to point to the desired page before the call instruction is executed. This can be done easily using SETB and CLRB instructions or writing a value to the STATUS register. The device also has the PAGE instruction, which automatically selects the page in a single-cycle execution. PAGE N PAGE N STATUS<6:5> JMP LABEL STATUS<6:5> 0 CALL LABEL PC<10:9> PC<8:0> PC<10:9> PC<8> PC<7:0> Note: "N" must be 0, 1, 2, or 3. Note:"N" must be 0, 1, 2, or 3. 15.10.3 Call Operation 15.11 Return Instructions The following happens when a CALL instruction is executed: The device has several instructions for returning from subroutines and interrupt service routines. The return from subroutine instructions are RET (return without affecting W), RETP (same as RET but affects PA1:PA0), RETI (return from interrupt), RETIW (return and add W to RTCC), and RETW #literal (return and place literal in W). The literal serves as an immediate data value from memory. This instruction can be used for table lookup operations. To do table lookup, the table must contain a string of RETW #literal instructions. The first instruction just in front of the table calculates the offset into the table. The table can be used as a result of a CALL. * The current value of the program counter is incremented and pushed onto the top of the stack. * The lower eight bits of the label address are copied into the lower eight bits of the program counter. * The ninth bit of the Program Counter is cleared to zero. * The page select bits (in STATUS register) are copied into the upper two bits of the Program Counter. This means that the call destination must start in the lower half of any page. For example, 00h-0FFh, 200h2FFh, 400h-4FFh, etc. STATUS<6:5> 0 PC<10:9> PC<8> CALL LABEL PC<7:0> (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 32 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 15.12 Subroutine Operation 15.12.1 Push Operation When a subroutine is called, the return address is pushed onto the subroutine stack. Specifically, each address in the stack is moved to the next lower level in order to make room for the new address to be stored. Stack 1 receives the contents of the program counter. Stack 8 is overwritten with what was in Stack 7. The contents of stack 8 are lost. 15.12.2 Pop Operation When a return instruction is executed the subroutine stack is popped. Specifically, the contents of Stack 1 are copied into the program counter and the contents of each stack level are moved to the next higher level. For example, Stack 1 receives the contents of Stack 2, etc., until Stack 7 is overwritten with the contents of Stack 8. Stack 8 is left unchanged, so the contents of Stack 8 are duplicated in Stack 7. PC<10:0> PC<10:0> STACK 1 STACK 1 STACK 2 STACK 2 STACK 3 STACK 3 STACK 4 STACK 4 STACK 5 STACK 5 STACK 6 STACK 6 STACK 7 STACK 7 STACK 8 STACK 8 (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 33 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 15.13 Comparison and Conditional Branch Instructions 15.17 Key to Abbreviations and Symbols The instruction set includes instructions such as DECSZ fr (decrement file register and skip if zero), INCSZ fr (increment file register and skip if zero), SNB bit (bit test file register and skip if bit clear), and SB bit (bit test file register and skip if bit set). These instructions will cause the next instruction to be skipped if the tested condition is true. If a skip instruction is immediately followed by a PAGE or BANK instruction (and the tested condition is true) then two instructions are skipped and the operation consumes three cycles. This is useful for conditional branching to another page where a PAGE instruction precedes a JMP. If several PAGE and BANK instructions immediately follow a skip instruction then they are all skipped plus the next instruction and a cycle is consumed for each. 15.14 Logical Instruction The instruction set contain a full complement of the logical instructions (AND, OR, Exclusive OR), with the W register and a selected memory location (using either direct or indirect addressing) serving as the two operands. 15.15 Shift and Rotate Instructions The instruction set includes instructions for left or right rotate-through-carry. 15.16 Complement and SWAP The device can perform one's complement operation on the file register (fr) and W register. The MOV W,<>fr instruction performs nibble-swap on the fr and puts the value into the W register. (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 34 - Symbol Description W Working register fr File register (memory-mapped register in the range of 00h to FFh) PC Lower eight bits of program counter (file register 02h) STATUS STATUS register (file register 03h) FSR C DC Z File Select Register (file register 04h) Carry bit in STATUS register (bit 0) Digit Carry bit in STATUS register (bit 1) Zero bit in STATUS register (bit 2 PD Power Down bit in STATUS register (bit 3) TO Watchdog Timeout bit in STATUS register (bit 4) PA2:PA0 Page select bits in STATUS register (bits 7:5) OPTION OPTION register (not memory-mapped) WDT Watchdog Timer register (not memorymapped) MODE MODE register (not memory-mapped) rx Port control register pointer (RA, RB, or RC) ! Non-memory-mapped register designator f File register address bit in opcode k Constant value bit in opcode n Numerical value bit in opcode b Bit position selector bit in opcode . File register / bit selector separator in assembly language instruction # Immediate literal designator in assembly language instruction lit Literal value in assembly language instruction addr8 8-bit address in assembly language instruction addr9 9-bit address in assembly language instruction addr12 12-bit address in assembly language instruction / Logical 1's complement | Logical OR ^ Logical exclusive OR & Logical AND <> Swap high and low nibbles (4-bit segments) << Rotate left through carry bit >> Rotate right through carry bit -- Decrement file register ++ Increment file register www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 16.0 INSTRUCTION SET SUMMARY TABLE Table 16-1 lists all of the instructions, organized by category. For each instruction, the table shows the instruction mnemonic (as written in assembly language), a brief description of what the instruction does, the number of instruction cycles required for execution, the binary opcode, and the status bits affected by the instruction. The "Cycles" column typically shows a value of 1, which means that the overall throughput for the instruction is one per clock cycle. In some cases, the exact number of cycles depends on the outcome of the instruction (such as the test-and-skip instructions) or the clocking mode (Compatible or Turbo). In those cases, all possible numbers of cycles are shown in the table. The instruction execution time is derived by dividing the oscillator frequency by either one (Turbo mode) or four (Compatible mode). The divide-by factor is selected through the FUSE Word register. Table 16-1. The SX Instruction Set Mnemonic, Operands Cycles Cycles (Compatible) (Turbo) Description Opcode Bits Affected Logical Operations AND fr, W AND of fr and W into fr (fr = fr & W) 1 1 0001 011f ffff Z AND W, fr AND of W and fr into W (W = W & fr) 1 1 0001 010f ffff Z AND W,#lit AND of W and Literal into W (W = W & lit) 1 1 1110 kkkk kkkk Z NOT fr Complement of fr into fr (fr = fr ^ FFh) 1 1 0010 011f ffff Z OR fr,W OR of fr and W into fr (fr = fr | W) 1 1 0001 001f ffff Z OR W,fr OR of W and fr into fr (W = W | fr) 1 1 0001 000f ffff Z OR W,#lit OR of W and Literal into W (W = W | lit) 1 1 1101 kkkk kkkk Z XOR fr,W XOR of fr and W into fr (fr = fr ^ W) 1 1 0001 101f ffff Z XOR W,fr XOR of W and fr into W (W = W ^ fr) 1 1 0001 100f ffff Z XOR W,#lit XOR of W and Literal into W (W = W ^ lit) 1 1 1111 kkkk kkkk Z Arithmetic and Shift Operations ADD fr,W Add W to fr (fr = fr + W); carry bit is added if CF bit in FUSEX register is cleared to 0 1 1 ADD W,fr Add fr to W (W = W + fr); carry bit is added if CF bit in FUSEX register is cleared to 0 1 1 CLR fr Clear fr (fr = 0) 1 1 0000 011f ffff Z CLR W Clear W (W = 0) 1 1 0000 0100 0000 Z CLR !WDT Clear Watchdog Timer, clear prescaler if assigned to the Watchdog (TO = 1, PD = 1) 1 1 DEC fr Decrement fr (fr = fr - 1) 1 1 DECSZ fr Decrement fr and Skip if Zero (fr = fr - 1 and skip next instruction if result is zero) INC fr Increment fr (fr = fr + 1) INCSZ fr Increment fr and Skip if Zero (fr = fr + 1 and skip next instruction if result is zero) RL fr Rotate fr Left through Carry (fr = << fr) 1 1 0011 011f ffff C RR fr Rotate fr Right through Carry (fr = >> fr) 1 1 0011 001f ffff C SUB fr,W Subtract W from fr (fr = fr - W); complement of the carry bit is subtracted if CF bit in FUSEX register is cleared to 0 1 1 Swap High/Low Nibbles of fr (fr = <> fr) 1 1 SWAP fr (c) 2000 Scenix Semiconductor, Inc. All rights reserved. 1 or 2 (skip) 1 - 35 - 1 or 2 (skip) 0001 111f ffff 0001 110f ffff 0000 0000 0100 0000 111f ffff 1 or 0010 111f ffff 2 (skip) 1 0010 101f ffff 1 or 0011 111f ffff 2 (skip) C, DC, Z C, DC, Z TO, PD Z none Z none 0000 101f ffff C, DC, Z 0011 101f ffff none www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 Table 16-1. The SX Instruction Set (Continued) Mnemonic, Operands Cycles Cycles (Compatible) (Turbo) Description Opcode Bits Affected Bitwise Operations CLRB fr.bit Clear Bit in fr (fr.bit = 0) SB fr.bit Test Bit in fr and Skip if Set (test fr.bit and skip next instruction if bit is 1) SETB fr.bit Set Bit in fr (fr.bit = 1) SNB fr.bit Test Bit in fr and Skip if Clear (test fr.bit and skip next instruction if bit is 0) 1 1 0100 bbbf ffff none 1 or 2 (skip) 1 or 2 (skip) 0111 bbbf ffff none 1 1 0101 bbbf ffff none 1 or 2 (skip) 1 or 2 (skip) 0110 bbbf ffff none Data Movement Instructions MOV fr,W Move W to fr (fr = W) 1 1 0000 001f ffff none MOV W,fr Move fr to W (W = fr) 1 1 0010 000f ffff Z MOV W,fr-W Move (fr-W) to W (W = fr - W); complement of carry bit is subtracted if CF bit in FUSEX register is cleared to 0 1 1 MOV W,#lit Move Literal to W (W = lit) 1 1 1100 kkkk kkkk none MOV W,/fr Move Complement of fr to W (W = fr ^ FFh) 1 1 0010 010f ffff Z MOV W,--fr Move (fr-1) to W (W = fr - 1) 1 1 0000 110f ffff Z MOV W,++fr Move (fr+1) to W (W = fr + 1) 1 1 0010 100f ffff Z MOV W,<<fr Rotate fr Left through Carry and Move to W (W = << fr) 1 1 MOV W,>>fr Rotate fr Right through Carry and Move to W (W = >> fr) 1 1 MOV W,<>fr Swap High/Low Nibbles of fr and move to W (W = <> fr) 1 1 MOV W,M Move MODE Register to W (W = MODE), high nibble is cleared 1 1 MOVSZ W,--fr Move (fr-1) to W and Skip if Zero (W = fr -1 and skip next instruction if result is zero) 1 or 2 (skip) 0010 110f ffff 1 2 (skip) none MOVSZ W,++fr Move (fr+1) to W and Skip if Zero (W = fr + 1 and skip next instruction if result is zero) 1 or 2 (skip) 0011 110f ffff 1 2 (skip) none MOV M,W Move W to MODE Register (MODE = W) 1 1 0000 0100 0011 none MOV M,#lit Move Literal to MODE Register (MODE = lit) 1 1 0000 0101 kkkk none MOV !rx,W Move W to Port Rx Control Register:rx <=> W (exchange W and WKPND_B or CMP_B) or rx = W (move W to rx for all other port control registers) 0000 100f ffff C, DC, Z 0011 010f ffff 0011 000f ffff 0011 100f ffff 0000 0100 0010 C C none none 0000 0000 0fff 1 1 MOV !OPTION, W Move W to OPTION Register (OPTION = W) 1 1 0000 0000 0010 none TEST fr 1 1 0010 001f ffff Z Test fr for Zero (fr = fr to set or clear Z bit) (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 36 - none www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 Table 16-1. The SX Instruction Set (Continued) Mnemonic, Operands Cycles Cycles (Compatible) (Turbo) Description Opcode Bits Affected Program Control instruction CALL addr8 JMP addr9 Call Subroutine: top-of-stack = program counter + 1 PC(7:0) = addr8 program counter (8) = 0 program counter (10:9) = PA1:PA0 1001 kkkk kkkk 2 3 Jump to Address: PC(7:0) = addr9(7:0) program counter (8) = addr9(8) program counter (10:9) = PA1:PA0 2 3 NOP No Operation 1 1 RET Return from Subroutine (program counter = top-of-stack) 2 3 RETP Return from Subroutine Across Page Boundary (PA1:PA0 = top-of-stack (10:9) and program counter = top-of-stack) 2 3 Return from Interrupt (restore W, STATUS, FSR, and program counter from shadow registers) 2 3 Return from Interrupt and add W to RTCC (restore W, STATUS, FSR, and program counter from shadow registers; and add W to RTCC) 2 3 Return from Subroutine with Literal in W (W = lit and program counter = top-of-stack) 2 3 RETI RETIW RETW lit none 101k kkkk kkkk none 0000 0000 0000 0000 0000 1100 none none 0000 0000 1101 PA1, PA0 0000 0000 1110 all STA- TUS, except TO, PD 0000 0000 1111 all STA- TUS, except TO, PD 1000 kkkk kkkk none System Control Instructions BANK addr8 Load Bank Number into FSR(7:5) FSR(7:5) = addr8(7:5) 1 1 IREAD Read Word from Instruction Memory MODE:W = data at (MODE:W) 1 4 PAGE addr12 Load Page Number into STATUS(7:5) STATUS(7:5) = addr12(11:9) 1 1 SLEEP Power Down Mode 0000 0001 1nnn 0000 0100 0001 0000 0001 0nnn none none PA1, PA0 0000 0000 0011 WDT = 00h, TO = 1, stop oscillator 1 1 TO, PD (PD = 0, clears prescaler if assigned) (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 37 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 16.1 Equivalent Assembler Mnemonics Some assemblers support additional instruction mnemonics that are special cases of existing instructions or alternative mnemonics for standard ones. For example, an assembler might support the mnemonic "CLC" (clear carry), which is interpreted the same as the instruction "clrb $03.0" (clear bit 0 in the STATUS register). Some of the commonly supported equivalent assembler mnemonics are described in Table 16-2. Table 16-2. Equivalent Assembler Mnemonics Syntax Description Equivalent Cycles CLC Clear Carry bit CLRB $03.0 1 CLZ Clear Zero bit CLRB $03.2 1 JMP W Jump Indirect W MOV $02,W 4 or 3 (note 1) JMP PC+W Jump Indirect W Relative ADD $02,W 4 or 3 (note 1) MODE imm4 Move Immediate to MODE Register MOV M,#lit NOT W Complement W XOR W,#$FF SC Skip if Carry bit Set SB $03.0 1 or 2 (note 2) SKIP Skip Next Instruction SNB $02.0 or SB $02.0 4 or 2 (note 3) 1 1 Note 1: The JMP W or JMP PC+W instruction takes 4 cycles in the "compatible" clocking mode or 3 cycles in the "turbo" clocking mode. Note 2: The SC instruction takes 1 cycle if the tested condition is false or 2 cycles if the tested condition is true. Note 3: The assembler converts the SKIP instruction into a SNB or SB instruction that tests the least significant bit of the program counter, choosing SNB or SB so that the tested condition is always true. The instruction takes 4 cycles in the "compatible" clocking mode or 2 cycles in the "turbo" clocking mode. (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 38 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 17.0 ELECTRICAL CHARACTERISTICS 17.1 Absolute Maximum Ratings -40C to +85C Ambient temperature under bias -65C to +150C Storage temperature Voltage on Vdd with respect to Vss 0 V to +7.0V Voltage on OSC1 with respect to Vss 0 V to +13.5V Voltage on MCLR with respect to Vss 0 V to +13.5V Voltage on all other pins with respect to V ss -0.6 V to (Vdd + 0.6V)V Total power dissipation 700 mW Max. current out of V ss pin 130 mA Max. current into Vdd pin 130 mA Max. DC current into an input pin (with internal protection diode forward biased) +500 A Max. allowable sink current per I/O pin 45 mA Max. allowable source current per I/O pin 45 mA (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 39 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 17.2 DC Characteristics SX18/20/28AC (Temp Range: 0C <= Ta <= +70C) and SX18/20/28AC-I (Temp Range: -40 C <= Ta <= +85C) Symbol Parameter Supply Voltage (Note 1) Vdd SVdd Conditions Min Typ Max Units Fosc= 32 MHz 2.7 - 5.5 V Fosc= 50 MHz 3.0 - 5.5 V 0.05 - - V/ms - 77 82 mA Vdd = 5.0V, Fosc = 4 MHz (Crystal) 7.5 8 mA Vdd = 2.7V, Fosc = 20 MHz (Crystal) 17 18 mA 10 20 A 1.0 9.0 A Vdd rise rate Supply Current, active Idd Supply Current, power down Ipd Vdd = 5.0V, Fosc = 50 MHz (Crystal) Vdd = 3.0V, WDT enabled - Vdd = 3.0V, WDT disabled Input Levels MCLR, OSC1, RTCC Logic High 0.8Vdd Vdd V Logic Low Vss 0.2Vdd V 0.7Vdd Vdd V Vss 0.3Vdd All Other Inputs Vih, Vil CMOS Logic High Logic Low TTL Logic High Logic Low Iil 2.0 Vdd Vss 0.8 V V V Input Leakage Current Vin = Vdd or Vss -1.0 +1.0 A Weak Pullup Current Vdd = 5.5V, Vin = 0V 100 190 A Vdd = 3.0V, Vin = 0V 25 50 A Iip Output High Voltage OSC2, Ports B, C Voh Port A Vol Ioh = 20mA, Vdd = 4.5V Vdd-0.7 V Ioh = 12mA, Vdd = 3.0V Vdd-0.7 V Ioh = 30mA, Vdd = 4.5 Vdd-0.7 V Ioh = 20mA, Vdd = 3.0V Vdd-0.7 V Output Low Voltage Iol = 30mA, Vdd = 4.5V 0.6 V All Ports, OSC2 Iol = 20mA, Vdd = 3.0V 0.6 V Note 1: Vdd must start rising from Vss to ensure proper Power-On-Reset when relying on the internal Power-On-Reset circuitry. (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 40 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 17.3 AC Characteristics SX18/20/28AC (Temp Range: 0C <= Ta <= +70C) and SX18/20/28AC-I (Temp Range: -40 C <= Ta <= +85C) Symbol Parameter Min Typ Max Units Conditions DC - 4.0 10 24 50 32 1.0 MHz MHz MHz MHz KHz MHz RC XT1 XT2 HS1/HS2/HS3 LP1 LP2 Oscillator Frequency DC 0.032 1.0 1.0 DC 0.032 - 4.0 10.0 24.0 50 32 1.0 MHz MHz MHz MHz KHz MHz RC XT1 XT2 HS1/HS2/HS3 LP1 LP2 External CLKIN Period 250 100 41.7 20 31.25 1.0 - - ns ns ns ns s s RC XT1 XT2 HS1/HS2/HS3 LP1 LP2 Oscillator Period 250 0.1 41.7 20 31.25 1.0 - 31.25 1000.0 1000.0 31.25 ns s ns ns s s RC XT1 XT2 HS1/HS2/HS3 LP1 LP2 Clock in (OSC1) Low or High Time 50 8.0 2.0 - - ns ns s XT1/XT2 HS1/HS2/HS3 LP1/LP2 Clock in (OSC1) Rise or Fall Time - - 25 25 50 ns ns s XT1/XT2 HS1/HS2/HS3 LP1/LP2 External CLKIN Frequency Fosc Tosc TosL, TosH TosR, TosF Note:Data in the Typical ("TYP") column is at 5V, 25 C unless otherwise stated. (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 41 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 17.4 DC Characteristics SX18/20/28AC75 (Temp Range: 0C <= Ta <= +70C) Symbol Parameter Vdd Supply Voltage (Note 1) SVdd Vdd rise rate Idd Ipd Conditions Min Typ Max Units Fosc= 75 MHz 4.5 - 5.5 V 0.05 - - V/ms - 100 105 mA 110 A 100 A Supply Current, active Vdd = 5.0V, Fosc = 75 MHz (Ext.) Supply Current, power down Vdd = 4.5V, WDT enabled Vdd = 4.5V, WDT disabled - Input Levels MCLR, OSC1, RTCC Logic High 0.8Vdd Vdd V Logic Low Vss 0.2Vdd V 0.7Vdd Vdd Vss 0.3Vdd 2.0 Vdd V Vss 0.8 V All Other Inputs Vih, Vil CMOS Logic High Logic Low TTL V V Logic High Logic Low Iil Input Leakage Current Vin = Vdd or Vss -1.0 +1.0 A Iip Weak Pullup Current Vdd = 5.5V, Vin = 0V 100 160 A Output High Voltage Voh Vol OSC2, Ports B, C Ioh = 20mA, Vdd = 4.5V Vdd-0.7 V Port A Ioh = 30mA, Vdd = 4.5 Vdd-0.7 V Output Low Voltage Iol = 30mA, Vdd = 4.5V All Ports, OSC2 0.6 V Note:Data in the Typical ("TYP") column is at 5V, 25 C unless otherwise stated. (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 42 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 17.5 AC Characteristics SX18/20/28AC75 (Temp Range: 0C <= Ta <= +70C) Symbol Parameter Min Typ Max Units Conditions 75 MHz HS1/HS2/HS3 External CLKIN Frequency DC Oscillator Frequency DC - 75 MHz HS1/HS2/HS3 External CLKIN Period 13.3 - - ns HS1/HS2/HS3 Oscillator Period 13.3 - - ns HS1/HS2/HS3 TosL, TosH Clock in (OSC1) Low or High Time 8.0 - - ns HS1/HS2/HS3 TosR, TosF Clock in (OSC1) Rise or Fall Time - - 25 ns HS1/HS2/HS3 Fosc Tosc Note:Data in the Typical ("TYP") column is at 5V, 25 C unless otherwise stated. 17.6 Comparator DC and AC Specifications Parameter Input Offset Voltage Conditions 0.4V < Vin < Vdd - 1.5V Input Common Mode Voltage Range Typ Max Units +/- 10 +/- 25 mV Vcc - 1.3 V 0.4 Voltage Gain 300k DC Supply Current (enabled) Response Time Min V/V Vdd = 5.5V 120 A Voverdrive = 25mV 250 ns (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 43 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 17.7 Typical Performance Characteristics (Room Temp) Active Supply Current Vs Operating Frequency (Crystal Clock) Active Supply Current Vs Operating Frequency (External Clock) 90 _ 90 _ 80 _ 60 50 40 _ V _ dd = 5. 70 Idd (mA) Idd (mA) 70 80 _ 5V _ _ 60 50 40 30 _ V dd = _ _ 20 _ 10 _ 10 _ 20 30 40 50 (c) 2000 Scenix Semiconductor, Inc. All rights reserved. V dd = 10 Operating Frequency (MHz) = _ 30 _ 3 .0 V d 5V _ 20 _ 10 Vd 5. 20 30 3 .0 V 40 50 Operating Frequency (MHz) - 44 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 17.7 Typical Performance Characteristics (continued) Active Supply Current Vs Operating Frequency (External Clock) Active Supply Current Vs Vdd (Crystal Clock) SX18AC75/SX20AC75/SX28AC75 90 _ 80 _ Idd (mA) Idd (mA) 100 _ 90 _ 60 50 40 _ 50 70 M H z 110 _ _ _ 40 _ M 32 30 _ 20 _ 80 _ 20 M M Hz Hz 8 MH 10 _ 4.5 5.5 5.0 Hz z 4 MHz 2.5 3.5 4.5 5.5 Vdd (V) Vdd (V) Active Supply Current Vs Vdd (32 kHz Crystal Clock) Active Supply Current Vs Vdd (External Clock) 90 _ 80 _ 60 50 40 z H _ 50 M 600 _ 40 _ _ 3 30 _ 20 _ Hz M 500 Idd ( A) Idd (mA) 70 700 Hz 2M 20 M _ _ _ 300 _ 200 _ Hz 8 MH 10 _ 100 _ z 3 4 MHz 2.5 400 _ 3.5 4.5 5.5 3.5 4 4.5 5 5.5 6 Vdd (V) Vdd (V) (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 45 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 17.7 Typical Performance Characteristics (continued) Active Supply Current Vs Vdd (32 kHz External Clock) 600 Port A/B/C Weak Pull-Up Source Current 160 _ V dd _ Ipup (A) Idd (A) 500 _ 400 _ 300 _ 120 _ 80 _ 40 _ =5 .5V 200 _ 100 _ 2 2.5 3 3.5 4 4.5 5 5.5 Vd 1 d =3 .0V 2 3 Vdd (V) 2 5V 4. = dd 3. 0V V = 20 _ V =3 3 .0 V .0V Iol (mA) V dd = V dd = V dd .5V V dd = 4 4 .5 V 30 _ dd A B Ioh (mA) Po rt Po rt Po rt A Po B rt 40 _ 10 _ 10 _ 1 6 Port A/B/C Sink Current 40 _ 20 _ 5 Voh (V) Port A/B/C Source Current 30 _ 4 3 4 5 6 0.5 Vol (V) Voh (V) (c) 2000 Scenix Semiconductor, Inc. All rights reserved. 1.0 - 46 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 18.0 PACKAGE DIMENSIONS (DIMENSIONS ARE IN INCHES/(MILLIMETERS) 0.035 - 0.045 (0.890 - 1.143) SX18AC/SO SX18AC75/SO 1 9 0.400 - 0.410 (10.16 - 10.41) 0.045 - 0.055 (1.143 - 1.397) 0.292 - 0.299 7.42 - 7.59) 0.090 - 0.094 (2.29 - 2.39) 10 0.292 - 0.299 (7.42 - 7.59) 28 0.014 - 0.019 (0.35 - 0.48) 0.050 BSC (1.27 BSC) 0.090 - 0.094 (2.29 - 2.39) 0.451 - 0.461 (11.46 - 11.71) SX18AC/DP SX18AC75/DP 0.0050 - 0.0115 (0.127 - 0.292) 0.895 - 0.905 (22.73 - 22.99) 9 1 0.240 - 0.260 (6.10 -6.60) 10 18 0.008 - 0.012 (0.20 - 0.31) 0.015 min. (0.38 min.) 0.130 nom. (3.3 nom.) 0.430 max. (10.92 max.) 0.170 max. (4.32 max.) 0.125 - 0.135 (3.17 - 3.43) o 0.300 BSC at 90 [ (7.62 BSC at 90 ) ] o 0.100 BSC (2.54 BSC) (c) 2000 Scenix Semiconductor, Inc. All rights reserved. 0.055 -0.065 (1.39 - 1.65) - 47 - 0.015 - 0.022 (0.38 - 0.56) www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 0.039 (1.00) SX20AC/SS SX20AC75/SS 1 10 0.301 - 0.311 (7.65 - 7.90) 0.039 (1.00) o 0.205 - 0.212 (5.20 - 5.38) o 12 - 16 11 20 0.066 - 0.070 (1.68 - 1.78) 0.205 - 0.212 (5.20 - 5.38) 0.0256 BSC (0.65 BSC) 0.010 - 0.015 (0.25 - 0.38) 0.066 - 0.070 (1.68 - 1.78) 0.278 - 0.289 (7.07 - 7.33) (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 48 - 0.002 - 0.008 (0.05 - 0.21) www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 0.035 - 0.045 (0.890 - 1.143) SX28AC/SO 14 1 SX28AC75/SO 0.40 - 0.41 (10.16 - 10.41) 0.045 - 0.055 (1.143 - 1.397) 0.292 - 0.299 7.42 - 7.59) 0.090 - 0.094 (2.29 - 2.39) 15 28 0.292 - 0.299 (7.42 - 7.59) 0.014 - 0.019 (0.35 - 0.48) 0.050 BSC (1.27 BSC) 0.090 - 0.094 (2.29 - 2.39) 0.701 - 0.710 (17.81 - 18.06) (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 49 - 0.0050 - 0.0115 (0.127 - 0.292) www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 SX28AC/DP SX28AC75/DP 1.360 - 1.370 (34.54 - 34.80) 1 14 0.280 - 0.295 (7.11 - 7.49) 28 15 0.009 - 0.014 (0.23 - 0.36) 0.020 min. (0.51 min.) 0.430 max. (10.92 max.) 0.130 nom. (3.3 nom.) o 0.300 BSC at 90 [ (7.62 BSC at 90 ) ] 0.180 max. (4.57 max.) o 0.120 - 0.135 (3.05 - 3.43) 0.100 BSC (2.54 BSC) (c) 2000 Scenix Semiconductor, Inc. All rights reserved. 0.045 - 0.055 (1.14 - 1.40) - 50 - 0.015 - 0.021 (0.38 - 0.53) www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 SX28AC/SS SX28AC75/SS 0.039 (1.00) 14 o 1 0.039 (1.00) o 12 - 16 15 0.301 - 0.311 (7.65 - 7.90) 0.205 - 0.212 (5.20 - 5.38) 28 0.066 - 0.070 (1.68 - 1.78) 0.205 - 0.212 (5.20 - 5.38) 0.010 - 0.015 (0.25 - 0.38) 0.0256 BSC (0.65 BSC) 0.002 - 0.008 (0.05 - 0.21) 0.066 - 0.070 (1.68 - 1.78) 0.397 - 0.407 (10.07 - 10.33) (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 51 - www.scenix.com SX18AC/SX20AC/SX28AC/SX18AC75/SX20AC75/SX28AC75 Lit #: SXL-DS01-04 Sales and Tech Support Contact Information For the latest contact and support information on SX devices, please visit the Scenix Semiconductor website at www.scenix.com. The site contains technical literature, local sales contacts, tech support and many other features. 1330 Charleston Road Mountain View, CA 94043 E-Mail: sales@scenix.com Web site: www.scenix.com Tel.: (650) 210-1500 Fax: (650) 210-8715 (c) 2000 Scenix Semiconductor, Inc. All rights reserved. - 52 - www.scenix.com