W78E054D/W78E052D/W78E051D Data Sheet
8-BIT MICROCONTROLLER
Publication Release Date: Oct 2 0, 2011
- 1 - Revision A10
Table of Contents-
1GENERAL DESCRIPTION ......................................................................................................... 4
2FEATURES ................................................................................................................................. 5
3PARTS INFORMATION LIST ..................................................................................................... 6
4PIN CONFIGURATIONS............................................................................................................. 7
5PIN DESCRIPTIONS .................................................................................................................. 9
6BLOCK DIAGRAM .................................................................................................................... 11
7FUNCTIONAL DESCRIPTION.................................................................................................. 12
7.1On-Chip Flash EPROM ................................................................................................ 12
7.2I/O Ports........................................................................................................................ 12
7.3Serial I/O ....................................................................................................................... 12
7.4Timers ........................................................................................................................... 12
7.5Interrupts....................................................................................................................... 12
7.6Data Pointers ................................................................................................................ 13
7.7Architecture................................................................................................................... 13
7.7.1ALU ................................................................................................................................13
7.7.2Accumulator ...................................................................................................................13
7.7.3B Register.......................................................................................................................13
7.7.4Program Status Word .....................................................................................................13
7.7.5Scratch-pad RAM ...........................................................................................................13
7.7.6Stack Pointer ..................................................................................................................13
8MEMORY ORGANIZATION...................................................................................................... 14
8.1Program Memory (on-chip Flash) ................................................................................. 14
8.2Scratch-pad RAM and Register Map............................................................................ 14
8.2.1Working Registers ..........................................................................................................16
8.2.2Bit addressable Locations ..............................................................................................17
8.2.3Stack ..............................................................................................................................17
9SPECIAL FUNCTION REGISTERS ......................................................................................... 18
9.1SFR Detail Bit Descriptions .......................................................................................... 20
10INSTRUCTION.......................................................................................................................... 35
10.1Instruction Timing.......................................................................................................... 43
11POWER MANAGEMENT.......................................................................................................... 44
11.1Idle Mode ...................................................................................................................... 44
11.2Power Down Mode ....................................................................................................... 44
12RESET CONDITIONS............................................................................................................... 45
12.1Sources of reset............................................................................................................ 45
12.1.1External Reset..............................................................................................................45
12.1.2Software Reset.............................................................................................................45
12.1.3Watchdog Timer Reset.................................................................................................45
W78E054D/W78E052D/W78E051D Data Sheet
- 2 -
12.2Reset State ................................................................................................................... 45
13INTERRUPTS ........................................................................................................................... 46
13.1Interrupt Sources .......................................................................................................... 46
13.2Priority Level Structure ................................................................................................. 46
13.3Interrupt Response Time .............................................................................................. 48
13.4Interrupt Inputs.............................................................................................................. 49
14PROGRAMMABLE TIMERS/COUNTERS ............................................................................... 50
14.1Timer/Counters 0 & 1.................................................................................................... 50
14.2Time-Base Selection..................................................................................................... 50
14.2.1Mode 0 .........................................................................................................................50
14.2.2Mode 1 .........................................................................................................................50
14.2.3Mode 2 .........................................................................................................................51
14.2.4Mode 3 .........................................................................................................................51
14.3Timer/Counter 2............................................................................................................ 52
14.3.1Capture Mode...............................................................................................................52
14.3.2Auto-Reload Mode, Counting up ..................................................................................53
14.3.3Auto-reload Mode, Counting Up/Down .........................................................................53
14.3.4Baud Rate Generator Mode .........................................................................................54
15WATCHDOG TIMER................................................................................................................. 55
16SERIAL PORT .......................................................................................................................... 57
16.1MODE 0 ........................................................................................................................ 57
16.2MODE 1 ........................................................................................................................ 58
16.3MODE 2 ........................................................................................................................ 59
17FLASH ROM CODE BOOT MODE SLECTION........................................................................ 62
18ISP (IN-SYSTEM PROGRAMMING) ........................................................................................ 63
19CONFIG BITS ........................................................................................................................... 67
20ELECTRICAL CHARACTERISTICS......................................................................................... 69
20.1Absolute Maximum Ratings .......................................................................................... 69
20.2DC ELECTRICAL CHARACTERISTICS ...................................................................... 70
20.3AC ELECTRICAL CHARACTERISTICS ...................................................................... 71
20.3.1Clock Input Waveform ..................................................................................................71
20.3.2Program Fetch Cycle....................................................................................................72
20.3.3Data Read Cycle ..........................................................................................................72
20.3.4Data Write Cycle...........................................................................................................72
20.3.5Port Access Cycle ........................................................................................................73
20.3.6Program Operation .......................................................................................................73
20.4TIMING waveforms....................................................................................................... 74
20.4.1Program Fetch Cycle....................................................................................................74
20.4.2Data Read Cycle ..........................................................................................................74
20.4.3Data Write Cycle...........................................................................................................75
20.4.4Port Access Cycle ........................................................................................................75
20.4.5Reset Pin Access Cycle ...............................................................................................76
21APPLICATION CIRCUITS ........................................................................................................ 77
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 3 - Revision A10
21.1External Program Memory and Crystal ........................................................................ 77
21.2Expanded External Data Memory and Oscillator.......................................................... 77
21.3Internal Program Memory and Oscillator for EFT application ...................................... 78
21.4Reference Value of XTAL ............................................................................................. 78
22APPLICATION NOTE ............................................................................................................... 79
23PACKAGE DIMENSIONS......................................................................................................... 84
23.140-pin DIP ..................................................................................................................... 84
23.244-pin PLCC ................................................................................................................. 85
23.344-pin PQFP ................................................................................................................. 86
23.448-pin LQFP.................................................................................................................. 87
24REVISION HISTORY ................................................................................................................88
W78E054D/W78E052D/W78E051D Data Sheet
- 4 -
1 GENERAL DESCRIPTION
The W78E054D/W78E052D/W78E051D series is an 8-bit microcontroller which can accommodate a
wider frequency range with low power consumption. The instruction set for the W78E054D/
W78E052D/ W78E051D series is fully compatible with the standard 8052.
The W78E054D/W78E052D/W78E051D series contains 16K/8K/4K bytes Flash EPROM programma-
ble by hardware writer; a 256 bytes RAM; four 8-bit bi-directional (P0, P1, P2, P3) and bit-addressable
I/O ports; an additional 4-bit I/O port P4; three 16-bit timer/counters; a hardware watchdog timer and a
serial port. These peripherals are supported by 8 sources 4-level interrupt capability. To facilitate pro-
gramming and verification, the Flash EPROM inside the W78E054D/W78E052D/W78E051D series
allows the program memory to be programmed and read electronically. Once the code is confirmed,
the user can protect the code for security.
The W78E054D/W78E052D/W78E051D series microcontroller has two power reduction modes, idle
mode and power-down mode, both of which are software selectable. The idle mode turns off the proc-
essor clock but allows for continued peripheral operation. The power-down mode stops the crystal os-
cillator for minimum power consumption. The external clock can be stopped at any time and in any
state without affecting the processor. The W78E054D/W78E052D/W78E051D series contains In-
System Programmable (ISP) 2KB LDROM for loader program, operating voltage from 3.3V to 5.5V.
Note: If the applied VDD is not stable, especially with long transition time of power on/off, it’s
recommended to apply an external RESET IC to the RST pin for improving the stability of sys-
tem.
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 5 - Revision A10
2 FEATURES
• Fully static design 8-bit CMOS microcontroller
• Optional 12T or 6T mode
12T Mode, 12 clocks per machine cycle operation (default), Speed up to 40 MHz/5V
6T Mode, 6 clocks per machine cycle operation set by the writer, Speed up to 20 MHz/5V
• Wide supply voltage of 2.4V to 5.5V
• Temperature grade is (-40oC~85oC)
• Pin and Instruction-sets compatible with MCS-51
• 256 bytes of on-chip scratchpad RAM
• 16K/8K/4K bytes electrically erasable/programmable Flash EPROM
• 2K bytes LDROM support ISP function (Reference Application Note)
• 64KB program memory address space
• 64KB data memory address space
• Four 8-bit bi-directional ports
• 8-sources, 4-level interrupt capability
• One extra 4-bit bit-addressable I/O port, additional INT2 /INT3 (available on PQFP, PLCC and
LQFP package)
• Three 16-bit timer/counters
• One full duplex serial port
• Watchdog Timer
• EMI reduction mode
• Software Reset
• Built-in power management with idle mode and power down mode
• Code protection
• Packages: DIP40, PLCC44, PQFP44, LQFP48
W78E054D/W78E052D/W78E051D Data Sheet
- 6 -
3 PARTS INFORMATION LIST
PART NO. RAM LDROM
SIZE APROM
SIZE PACKAGE Temperature
grade
2K Bytes 14K Bytes
W78E054DDG
0 16K Bytes
DIP-40 Pin -40oC~85oC
2K Bytes 14K Bytes
W78E054DPG 0 16K Bytes
PLCC-44 Pin -40oC~85oC
2K Bytes 14K Bytes
W78E054DFG
0 16K Bytes
PQFP-44 Pin -40oC~85oC
2K Bytes 14K Bytes
W78E054DLG 0 16K Bytes
LQFP-48 Pin -40oC~85oC
W78E052DDG DIP-40 Pin -40oC~85oC
W78E052DPG PLCC-44 Pin -40oC~85oC
W78E052DFG PQFP-44 Pin -40oC~85oC
W78E052DLG
2K Bytes 8K Bytes
LQFP-48 Pin -40oC~85oC
W78E051DDG DIP-40 Pin -40oC~85oC
W78E051DPG PLCC-44 Pin -40oC~85oC
W78E051DFG PQFP-44 Pin -40oC~85oC
W78E051DLG
256
Bytes
2K Bytes 4K Bytes
LQFP-48 Pin -40oC~85oC
Table 3–1: Lad Free (RoHS) Parts information list
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 7 - Revision A10
4 PIN CONFIGURATIONS
186
5
4
3
2
1
44
43
42
41
40
19
20
21
22
23
24
25
26
27
28
P1.3
P1.2
P1.4
T2EX, P1.1
T2, P1.0
AD0, P0.0
INT3, P4.2
AD1, P0.1
AD2, P0.2
AD3, P0.3
VDD
XTAL2
XTAL1
VSS
P2.1, A9
P4.0
P2.2, A10
P2.3, A11
P2.4, A12
P2.0, A8
P3.7, RD
P3.6, WR
DIP 40-pin
W78E054D/W78E052D/W78E051D Data Sheet
- 8 -
8
12
37
7
10
9
11
44
43
42
41
40
39
38
36
35
34
32
33
30
31
28
29
26
27
24
25
23
13
14
15
16
17
18
19
20
21
22
P1.6
P1.5
RST
P1.7
RXD, P3.0
TXD, P3.1
T0, P3.4
T1, P3.5
P1.3
P1.2
P1.4
T2EX, P1.1
T2, P1.0
AD0, P0.0
AD1, P0.1
AD2, P0.2
AD3, P0.3
VDD
ALE
P0.7, AD7
P4.1
P0.6, AD6
P0.5, AD5
P0.4, AD4
P2.5, A13
P2.6, A14
P2.7, A15
XTAL2
XTAL1
VSS
P2.1, A9
P4.0
P2.2, A10
P2.3, A11
P2.0, A8
PQFP 44-pin
INT0, P3.2
P3.7, RD
INT1, P3.3
PSEN
EA
P3.6, WR
2
1
4
3
5
6
INT2, P4.3
INT3, P4.2
2
44
1
4
3
6
5
8
7
10
9
11
48
42
41
40
39
38
37
32
33
30
31
28
29
26
27
25
13
14
15
16
18
19
20
21
22
P2.7, A15
PSEN
AD0, P0.0
ALE
EA
P4.1
P0.6, AD6
P0.5, AD5
P2.4, A12
P2.3, A11
P2.2, A10
P2.1, A9
XTAL2
P3.7, RD
P3.6, WR
XTAL1
INT2, P4.3
INT0, P3.2
INT1, P3.3
T0, P3.4
T1, P3.5
P1.6
P1.7
RST
AD2, P0.3
AD2, P0.2
AD1, P0.1
P1.3
P1.4
P1.5
P1.2
P2.0, A8
P4.0
VSS
12
17
23
24
34
35
36
46
47
43
45
P2.6, A14
P2.5, A13
NC
VDD
INT3, P4.2
T2, P1.0
T2EX, P1.1
P0.7, AD7
P0.4, AD4
P3.1
P3.0
NC
NC
NC
LQFP 48-pin
P2.4, A12
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 9 - Revision A10
5 PIN DESCRIPTIONS
SYMBOL TYPE DESCRIPTIONS
EA I
EXTERNAL ACCESS ENABLE: This pin forces the processor to execute out o
f
external ROM. It should be kept high to access internal ROM. The ROM address
and data will not be present on the bus if E
A
pin is high and the program coun-
ter is within internal ROM area. Otherwise they will be present on the bus.
PSEN O H
PROGRAM STORE ENABLE: PSEN enables the external ROM data onto the
Port 0 address/data bus during fetch and MOVC operations. When internal ROM
access is performed, no PSEN strobe signal outputs from this pin.
ALE O H
ADDRESS LATCH ENABLE: ALE is used to enable the address latch that sepa-
rates the address from the data on Port 0.
RST I L
RESET: A high on this pin for two machine cycles while the oscillator is running
resets the device.
XTAL1 I
CRYSTAL1: This is the crystal oscillator input. This pin may be driven by an ex-
ternal clock.
XTAL2 O CRYSTAL2: This is the crystal oscillator output. It is the inversion of XTAL1.
VSS I GROUND: Ground potential
VDD I POWER SUPPLY: Supply voltage for operation.
P0.0−P0.7 I/O D PORT 0: Port 0 is an open-drain bi-directional I/O port. This port also provides a
multiplexed low order address/data bus during accesses to external memory.
P1.0−P1.7 I/O H
PORT 1: Port 1 is a bi-directional I/O port with internal pull-ups. The bits have
alternate functions which are described below:
T2 (P1.0): Timer/Counter 2 external count input
T2EX (P1.1): Timer/Counter 2 Reload/Capture control
P2.0−P2.7 I/O H PORT 2: Port 2 is a bi-directional I/O port with internal pull-ups. This port also
provides the upper address bits for accesses to external memory.
W78E054D/W78E052D/W78E051D Data Sheet
- 10 -
Pin Description, continued
SYMBOL TYPE DESCRIPTIONS
P3.0−P3.7 I/O H
PORT 3: Port 3 is a bi-directional I/O port with internal pull-ups. All bits have al-
ternate functions, which are described below:
RXD (P3.0): Serial Port 0 input
TXD (P3.1): Serial Port 0 output
INT0 (P3.2) : External Interrupt 0
INT1 (P3.3) : External Interrupt 1
T0 (P3.4) : Timer 0 External Input
T1 (P3.5) : Timer 1 External Input
WR (P3.6) : External Data Memory Write Strobe
RD (P3.7) : External Data Memory Read Strobe
P4.0−P4.3 I/O H
PORT 4: Another bit-addressable bidirectional I/O port P4. P4.3 and P4.2 are
alternative function pins. It can be used as general I/O port or external interrupt
input sources (INT2 /INT3 ).
* Note: TYPE I: input, O: output, I/O: bi-directional, H: pull-high, L: pull-low, D: open drain.
In application if MCU pins need external pull-up, it is recommended to add a pull-up resistor
(10KΩ) between pin and power (VDD) instead of directly wiring pin to VDD for enhancing EMC.
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 11 - Revision A10
6 BLOCK DIAGRAM
Figure 6–1 W78E054D/W78E052D/W78E051D Block Diagram
W78E054D/W78E052D/W78E051D Data Sheet
- 12 -
7 FUNCTIONAL DESCRIPTION
The W78E054D/W78E052D/W78E051D series architecture consists of a core controller surrounded
by various registers, five general purpose I/O ports, 16K/8K/4K flash EPROM, 2K FLASH EPROM for
ISP function, 256 bytes of RAM, three timer/counters, and a serial port. The processor supports 111
different op-codes and references both a 64K program address space and a 64K data storage space.
7.1 On-Chip Flash EPROM
The W78E054D/W78E052D/W78E051D series include one 16K/8K/4K bytes of main Flash EPROM
for application program.
7.2 I/O Ports
The W78E054D/W78E052D/W78E051D series has four 8-bit ports and one extra 4-bit port. Port 0 can
be used as an Address/Data bus when external program is running or external memory/device is ac-
cessed by MOVC or MOVX instruction. In these cases, it has strong pull-ups and pull-downs, and
does not need any external pull-ups. Otherwise it can be used as a general I/O port with open-drain
circuit. Port 2 is used chiefly as the upper 8-bits of the Address bus when port 0 is used as an ad-
dress/data bus. It also has strong pull-ups and pull-downs when it serves as an address bus. Port1
and 3 act as I/O ports with alternate functions. Port 4 is only available on PLCC/PQFP/LQFP package
type. It serves as a general purpose I/O port as Port 1 and Port 3. Another bit-addressable bidirec-
tional I/O port P4. P4.3 and P4.2 are alternative function pins. It can be used as general I/O port or
external interrupt input sources (INT2 /INT3 ).
7.3 Serial I/O
The W78E054D/W78E052D/W78E051D series have one serial port that is functionally similar to the
serial port of the original 8032 family. However the serial port on the W78E054D/ W78E052D/
W78E051D series can operate in different modes in order to obtain timing similarity as well.
7.4 Timers
Timers 0, 1, and 2 each consist of two 8-bit data registers. These are called TL0 and TH0 for Timer 0,
TL1 and TH1 for Timer 1, and TL2 and TH2 for Timer 2. The TCON and TMOD registers provide con-
trol functions for timers 0 and 1. The T2CON register provides control functions for Timer 2. RCAP2H
and RCAP2L are used as reload/capture registers for Timer 2.
The operations of Timer 0 and Timer 1 are the same as in the 8051 CPU. Timer 2 is a special feature
of the W78E054D/W78E052D/W78E051D: it is a 16-bit timer/counter that is configured and controlled
by the T2CON register. Like Timers 0 and 1, Timer 2 can operate as either an external event counter
or as an internal timer, depending on the setting of bit C/T2 in T2CON. Timer 2 has three operating
modes: capture, auto-reload, and baud rate generator. The clock speed at capture or auto-reload
mode is the same as that of Timers 0 and 1.
7.5 Interrupts
The Interrupt structure in the W78E054D/W78E052D/W78E051D is slightly different from that of the
standard 8052. Due to the presence of additional features and peripherals, the number of interrupt
sources and vectors has been increased. The W78E054D/W78E052D/W78E051D provides 8 interrupt
resources with four priority level, including four external interrupt sources, three timer interrupts, serial
I/O interrupts.
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 13 - Revision A10
7.6 Data Pointers
The data pointer of W78E054D/W78E052D/W78E051D series is same as standard 8052 that have
one 16-bit Data Pointer (DPTR).
7.7 Architecture
The W78E054D/W78E052D/W78E051D series are based on the standard 8052 device. It is built
around an 8-bit ALU that uses internal registers for temporary storage and control of the peripheral
devices. It can execute the standard 8052 instruction set.
7.7.1 ALU
The ALU is the heart of the W78E054D/W78E052D/W78E051D series. It is responsible for the arith-
metic and logical functions. It is also used in decision making, in case of jump instructions, and is also
used in calculating jump addresses. The user cannot directly use the ALU, but the Instruction Decoder
reads the op-code, decodes it, and sequences the data through the ALU and its associated registers
to generate the required result. The ALU mainly uses the ACC which is a special function register
(SFR) on the chip. Another SFR, namely B register is also used Multiply and Divide instructions. The
ALU generates several status signals which are stored in the Program Status Word register (PSW).
7.7.2 Accumulator
The Accumulator (ACC) is the primary register used in arithmetic, logical and data transfer operations
in the W78E054D/W78E052D/W78E051D series. Since the Accumulator is directly accessible by the
CPU, most of the high speed instructions make use of the ACC as one argument.
7.7.3 B Register
This is an 8-bit register that is used as the second argument in the MUL and DIV instructions. For all
other instructions it can be used simply as a general purpose register.
7.7.4 Program Status Word
This is an 8-bit SFR that is used to store the status bits of the ALU. It holds the Carry flag, the Auxiliary
Carry flag, General purpose flags, the Register Bank Select, the Overflow flag, and the Parity flag.
7.7.5 Scratch-pad RAM
The W78E054D/W78E052D/W78E051D series has a 256 byte on-chip scratch-pad RAM. This can be
used by the user for temporary storage during program execution. A certain section of this RAM is bit
addressable, and can be directly addressed for this purpose.
7.7.6 Stack Pointer
The W78E054D/W78E052D/W78E051D series has an 8-bit Stack Pointer which points to the top of
the Stack. This stack resides in the Scratch Pad RAM in the W78E054D/W78E052D/W78E051D.
Hence the size of the stack is limited by the size of this RAM.
W78E054D/W78E052D/W78E051D Data Sheet
- 14 -
8 MEMORY ORGANIZATION
The W78E054D/W78E052D/W78E051D series separate the memory into two separate sections, the
Program Memory and the Data Memory. The Program Memory is used to store the instruction op-
codes, while the Data Memory is used to store data or for memory mapped devices.
Indirect
Addressing
RAM
Direct &
Indirect
Addressing
RAM
SFRs Direct
Addressing
Only
00H
7FH
80H
FFH
64K Bytes
External
Data
memory
14K/8K/4KB
APROM
FFFFH
0000H
3FFFH
3800H
2KB
LDROM
0000H
16KB
APROM
3FFFH
0000H
or
Figure 8–1 Memory Map
8.1 Program Memory (on-chip Flash)
The Program Memory on the W78E054D/W78E052D/W78E051D series can be up to 16K/8K/4K
bytes (2K bytes for ISP F/W, share with the W78E054D) long. All instructions are fetched for execution
from this memory area. The MOVC instruction can also access this memory region.
8.2 Scratch-pad RAM and Register Map
As mentioned before the W78E054D/W78E052D/W78E051D series have separate Program and Data
Memory areas. There are also several Special Function Registers (SFRs) which can be accessed by
software. The SFRs can be accessed only by direct addressing, while the on-chip RAM can be ac-
cessed by either direct or indirect addressing.
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 15 - Revision A10
Indirect
RAM
Addressing
Direct
&
Indirect
RAM
Addressing
SFR
Direct
Addressing
Only
00H
7FH
80H
FFH
256 bytes RAM and SFR Data Memory Space
Figure 8–2 W78E054D/W78E052D/W78E051D RAM and SFR Memory Map
Since the scratch-pad RAM is only 256bytes it can be used only when data contents are small. There
are several other special purpose areas within the scratch-pad RAM. These are illustrated in next fig-
ure.
W78E054D/W78E052D/W78E051D Data Sheet
- 16 -
Bank 0
Bank 1
Bank 2
Bank 3
03 02 01 0004050607
0B 0A 09 080C0D0E0F
13 12 11 1014151617
1B 1A 19 181C1D1E1F
23 22 21 2024252627
2B 2A 29 282C2D2E2F
33 32 31 30
34
353637
3B 3A 39 383C3D3E3F
43 42 41 4044
454647
4B 4A 49 484C4D4E4F
53 52 51 5054555657
5B 5A 59 585C5D5E5F
63 62 61 6064656667
6B 6A 69 686C6D6E6F
73 72 71 7074757677
7B 7A 79 787C7D7E7F
Direct RAM
Indirect RAM
00H
07H
28H
08H
0FH
10H
17H
18H
1FH
20H
21H
22H
23H
24H
25H
26H
27H
29H
2AH
2BH
2CH
2DH
2EH
2FH
30H
7FH
80H
FFH
Figure 8–3 Scratch-pad RAM
8.2.1 Working Registers
There are four sets of working registers, each consisting of eight 8-bit registers. These are termed as
Banks 0, 1, 2, and 3. Individual registers within these banks can be directly accessed by separate in-
structions. These individual registers are named as R0, R1, R2, R3, R4, R5, R6 and R7. However, at
one time the W78E054D/W78E052D/W78E051D series can work with only one particular bank. The
bank selection is done by setting RS1-RS0 bits in the PSW. The R0 and R1 registers are used to store
the address for indirect accessing.
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 17 - Revision A10
8.2.2 Bit addressable Locations
The Scratch-pad RAM area from location 20h to 2Fh is byte as well as bit addressable. This means
that a bit in this area can be individually addressed. In addition some of the SFRs are also bit ad-
dressable. The instruction decoder is able to distinguish a bit access from a byte access by the type of
the instruction itself. In the SFR area, any existing SFR whose address ends in a 0 or 8 is bit address-
able.
8.2.3 Stack
The scratch-pad RAM can be used for the stack. This area is selected by the Stack Pointer (SP),
which stores the address of the top of the stack. Whenever a jump, call or interrupt is invoked the re-
turn address is placed on the stack. There is no restriction as to where the stack can begin in the
RAM. By default however, the Stack Pointer contains 07h at reset. The user can then change this to
any value desired. The SP will point to the last used value. Therefore, the SP will be incremented and
then address saved onto the stack. Conversely, while popping from the stack the contents will be read
first, and then the SP is decreased.
W78E054D/W78E052D/W78E051D Data Sheet
- 18 -
9 SPECIAL FUNCTION REGISTERS
The W78E054D/W78E052D/W78E051D series uses Special Function Registers (SFRs) to control and
monitor peripherals and their Modes. The SFRs reside in the register locations 80-FFh and are ac-
cessed by direct addressing only. Some of the SFRs are bit addressable. This is very useful in cases
where users wish to modify a particular bit without changing the others. The SFRs that are bit ad-
dressable are those whose addresses end in 0 or 8. The W78E054D/W78E052D/W78E051D series
contain all the SFRs present in the standard 8052. However some additional SFRs are added. In
some cases the unused bits in the original 8052, have been given new functions. The list of the SFRs
is as follows.
F8 FF
F0 B F7
E8 EF
E0 ACC E7
D8 P4 DF
D0 PSW D7
C8 T2CON T2MOD RCAP2L RCAP2H TL2 TH2 CF
C0 XICON SFRAL SFRAH SFRRD SFRCN C7
B8 IP EAPAGE CHPCON BF
B0 P3 IPH B7
A8 IE AF
A0 P2 A7
98 SCON SBUF 9F
90 P1 97
88 TCON TMOD TL0 TL1 TH0 TH1 AUXR WDTC 8F
80 P0 SP DPL DPH P0UPR PCON 87
Table 9–1: Special Function Register Location Table
Note:
1. The SFRs in the column with dark borders are bit-addressable
2. The table is condensed with eight locations per row. Empty locations indicate that these are no reg-
isters at these addresses. When a bit or register is not implemented, it will read high.
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 19 - Revision A10
Special Function Registers:
SYMBOL DEFINITION ADDRESS MSB BIT ADDRESS, SYMBOL LSB RESET
B B register F0H (F7) (F6) (F5) (F4) (F3) (F2) (F1) (F0) 0000 0000B
ACC Accumulator E0H (E7) (E6) (E5) (E4) (E3) (E2) (E1) (E0) 0000 0000B
P4 Port 4 D8H INT2 INT3 0000 1111B
PSW Program status word D0H (D7)
CY
(D6)
AC
(D5)
F0
(D4)
RS1
(D3)
RS0
(D2)
OV
(D1)
F1
(D0)
P
0000 0000B
TH2 T2 reg. high CDH 0000 0000B
TL2 T2 reg. low CCH 0000 0000B
RCAP2H T2 capture low CBH 0000 0000B
RCAP2L T2 capture high CAH 0000 0000B
T2MOD Timer 2 Mode C9 DCEN 0000 0000B
T2CON Timer 2 control C8H (CF)
TF2
(CE)
EXF2
(CD)
RCLK
(CC)
TCLK
(CB)
EXEN2
(CA)
TR2
(C9)
C/T2
(C8)
CP/RL2
0000 0000B
SFRCN SFR program of control C7H NOE NCE CTRL3 CTRL2 CTRL1 CTRL0 0000 0000B
SFRRD SFR program of data register C6H 0000 0000B
SFRAH SFR program of address high byte C5H 0000 0000B
SFRAL SFR program of address low byte C4H 0000 0000B
XICON External interrupt control C0H PX3 EX3 IE3 IT3 PX2 EX2 IE2 IT2 0000 0000B
CHPCON Chip control BFH SWRST - - - - FBOOTS
L ENP 0000 0000B
EAPAGE Erase page operation modes BEH EAPG1 EAPG0 0000 0000B
IP Interrupt priority B8H (BF)
-
(BE)
-
(BD)
PT2
(BC)
PS
(BB)
PT1
(BA)
PX1
(B9)
PT0
(B8)
PX0
1100 0000B
IPH Interrupt priority High B7H 0000 0000B
P3 Port 3 B0H (B7)
RD
(B6)
WR
(B5)
T1
(B4)
T0
(B3)
INT1
(B2)
INT0
(B1)
TXD
(B0)
RXD
1111 1111B
IE Interrupt enable A8H (AF)
EA
(AE)
-
(AD)
ET2
(AC)
ES
(AB)
ET1
(AA)
EX1
(A9)
ET0
(A8)
EX0
0100 0000B
P2 Port 2 A0H (A7)
A15
(A6)
A14
(A5)
A13
(A4)
A12
(A3)
A11
(A2)
A10
(A1)
A9
(A0)
A8
1111 1111B
SBUF Serial buffer 99H 0000 0000B
SCON Serial control 98H (9F)
SM0/FE
(9E)
SM1
(9D)
SM2
(9C)
REN
(9B)
TB8
(9A)
RB8
(99)
TI
(98)
RI
0000 0000B
P1 Port 1 90H (97)
(96)
(95)
(94)
(93)
(92)
(91)
T2EX
(90)
T2
1111 1111B
WDTC Watchdog control 8FH ENW CLRW WIDL - - PS2 PS1 PS0 0000 0000B
AUXR Auxiliary 8EH - - - - ALEOFF 0000 0110B
TH1 Timer high 1 8DH 0000 0000B
TH0 Timer high 0 8CH 0000 0000B
TL1 Timer low 1 8BH 0000 0000B
TL0 Timer low 0 8AH 0000 0000B
TMOD Timer mode 89H GATE C/T M1 M0 GATE C/T M1 M0 0000 0000B
TCON Timer control 88H (8F)
TF1
(8E)
TR1
(8D)
TF0
(8C)
TR0
(8B)
IE1
(8A)
IT1
(89)
IE0
(88)
IT0
0000 0000B
PCON Power control 87H SMOD SMOD0 - POR GF1 GF0 PD IDL 0011 0000B
P0UPR Port 0 pull up option Register 86H - - - - - - - P0UP 0000 0001B
DPH Data pointer high 83H 0000 0000B
W78E054D/W78E052D/W78E051D Data Sheet
- 20 -
DPL Data pointer low 82H 0000 0000B
SP Stack pointer 81H 0000 0111B
P0 Port 0 80H (87) (86) (85) (84) (83) (82) (81) (80) 1111 1111B
9.1 SFR Detail Bit Descriptions
Port 0
Bit: 7 6 5 4 3 2 1 0
P0.7 P0.6 P0.5 P0.4 P0.3 P0.2 P0.1 P0.0
Mnemonic: P0 Address: 80h
BIT NAME FUNCTION
7-0 P0.[7:0] Port 0 is an open-drain bi-directional I/O port if SFR P0UPR.0 (bit P0UP) clear to “0”, and
when SFR P0UPR.0 (bit P0UP) set to “1”, Port 0 pins are internally pulled-up.
This port also provides a multiplexed low order address/data bus during accesses to external
memory.
STACK POINTER
Bit: 7 6 5 4 3 2 1 0
SP.7 SP.6 SP.5 SP.4 SP.3 SP.2 SP.1 SP.0
Mnemonic: SP Address: 81h
BIT NAME FUNCTION
7-0 SP.[7:0] The Stack Pointer stores the Scratch-pad RAM address where the stack begins. In other
words it always points to the top of the stack.
DATA POINTER LOW
Bit: 7 6 5 4 3 2 1 0
DPL.7 DPL.6 DPL.5 DPL.4 DPL.3 DPL.2 DPL.1 DPL.0
Mnemonic: DPL Address: 82h
BIT NAME FUNCTION
7-0 DPL.[7:0] This is the low byte of the standard 8052 16-bit data pointer.
DATA POINTER HIG H
Bit: 7 6 5 4 3 2 1 0
DPH.7 DPH.6 DPH.5 DPH.4 DPH.3 DPH.2 DPH.1 DPH.0
Mnemonic: DPH Address: 83h
BIT NAME FUNCTION
7-0 DPH.[7:0] This is the high byte of the standard 8052 16-bit data pointer.
Port 0 Pull Up Option Register
Bit: 7 6 5 4 3 2 1 0
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 21 - Revision A10
- - - - - - - P0UP
Mnemonic: P0UPR Address: 86h
BIT NAME FUNCTION
0 P0UP 0: Port 0 pins are open-drain.
1: Port 0 pins are internally pulled-up. Port 0 is structurally the same as Port 2.
Power Control
Bit: 7 6 5 4 3 2 1 0
SMOD SMOD0 - POR GF1 GF0 PD IDL
Mnemonic: PCON Address: 87h
BIT NAME FUNCTION
7 SMOD 1: This bit doubles the serial port baud rate in mode 1, 2, and 3 when set to 1.
6 SMOD
0
0: Framing Error Detection Disable. SCON.7 (SM0/FE) bit is used as SM0 (stan-
dard 8052 function).
1: Framing Error Detection Enable. SCON.7 (SM0/FE) bit is used to reflect as
Frame Error (FE) status flag.
5 - Reserved
4 POR 0: Cleared by software.
1: Set automatically when a power-on reset has occurred.
3 GF1 General purpose user flags.
2 GF0 General purpose user flags.
1 PD 1: The CPU goes into the POWER DOWN mode. In this mode, all the clocks are
stopped and program execution is frozen.
0 IDL 1: The CPU goes into the IDLE mode. In this mode, the clocks CPU clock stopped,
so program execution is frozen. But the clock to the serial, timer and interrupt
blocks is not stopped, and these blocks continue operating.
Timer Control
Bit: 7 6 5 4 3 2 1 0
TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0
Mnemonic: TCON Address: 88h
BIT NAME FUNCTION
7 TF1 Timer 1 Overflow Flag. This bit is set when Timer 1 overflows. It is cleared auto-
matically when the program does a timer 1 interrupt service routine. Software can
also set or clear this bit.
6 TR1 Timer 1 Run Control. This bit is set or cleared by software to turn timer/counter on
or off.
5 TF0 Timer 0 Overflow Flag. This bit is set when Timer 0 overflows. It is cleared auto-
matically when the program does a timer 0 interrupt service routine. Software can
also set or clear this bit.
W78E054D/W78E052D/W78E051D Data Sheet
- 22 -
4 TR0 Timer 0 Run Control. This bit is set or cleared by software to turn timer/counter on
or off.
3 IE1 Interrupt 1 Edge Detect Flag: Set by hardware when an edge/level is detected on
1INT . This bit is cleared by hardware when the service routine is vectored to only if
the interrupt was edge triggered. Otherwise it follows the inverse of the pin.
2 IT1 Interrupt 1 Type Control. Set/cleared by software to specify falling edge/ low level
triggered external inputs.
1 IE0 Interrupt 0 Edge Detect Flag. Set by hardware when an edge/level is detected
on 0INT . This bit is cleared by hardware when the service routine is vectored to
only if the interrupt was edge triggered. Otherwise it follows the inverse of the pin.
0 IT0 Interrupt 0 Type Control: Set/cleared by software to specify falling edge/ low level
triggered external inputs.
Timer Mode Control
Bit: 7 6 5 4 3 2 1 0
GATE TC / M1 M0 GATE TC/ M1 M0
TIMER1 TIMER0
Mnemonic: TMOD Address: 89h
BIT NAME FUNCTION
7 GATE
Gating control: When this bit is set, Timer/counter 1 is enabled only while the 1INT
pin is high and the TR1 control bit is set. When cleared, the 1INT pin has no effect,
and Timer 1 is enabled whenever TR1 control bit is set.
6 TC/ Timer or Counter Select: When clear, Timer 1 is incremented by the internal clock.
When set, the timer counts falling edges on the T1 pin.
5 M1 Timer 1 mode select bit 1. See table below.
4 M0 Timer 1 mode select bit 0. See table below.
3 GATE
Gating control: When this bit is set, Timer/counter 0 is enabled only while the 0INT
pin is high and the TR0 control bit is set. When cleared, the 0INT pin has no ef-
fect, and Timer 0 is enabled whenever TR0 control bit is set.
2 TC/ Timer or Counter Select: When clear, Timer 0 is incremented by the internal clock.
When set, the timer counts falling edges on the T0 pin.
1 M1 Timer 0 mode select bit 1. See table below.
0 M0 Timer 0 mode select bit 0. See table below.
M1, M0: Mode Select bits:
M1 M0 MODE
0 0
Mode 0: 13-bit timer/counter TLx serves as 5-bit pre-scale.
0 1
Mode 1: 16-bit timer/counter, no pre-scale.
1 0
Mode 2: 8-bit timer/counter with auto-reload from THx.
1 1
Mode 3: (Timer 0) TL0 is an 8-bit timer/counter controlled by the standard Timer0
control bits. TH0 is an 8-bit timer only controlled by Timer1 control bits. (Timer 1)
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 23 - Revision A10
Timer/Counter 1 is stopped.
Timer 0 LSB
Bit: 7 6 5 4 3 2 1 0
TL0.7 TL0.6 TL0.5 TL0.4 TL0.3 TL0.2 TL0.1 TL0.0
Mnemonic: TL0 Address: 8Ah
BIT NAME FUNCTION
7-0 TL0.[7:0] Timer 0 LSB.
Timer 1 LSB
Bit: 7 6 5 4 3 2 1 0
TL1.7 TL1.6 TL1.5 TL1.4 TL1.3 TL1.2 TL1.1 TL1.0
Mnemonic: TL1 Address: 8Bh
BIT NAME FUNCTION
7-0 TL1.[7:0] Timer 1 LSB.
Timer 0 MSB
Bit: 7 6 5 4 3 2 1 0
TH0.7 TH0.6 TH0.5 TH0.4 TH0.3 TH0.2 TH0.1 TH0.0
Mnemonic: TH0 Address: 8Ch
BIT NAME FUNCTION
7-0 TH0.[7:0] Timer 0 MSB.
Timer 1 MSB
Bit: 7 6 5 4 3 2 1 0
TH1.7 TH1.6 TH1.5 TH1.4 TH1.3 TH1.2 TH1.1 TH1.0
Mnemonic: TH1 Address: 8Dh
BIT NAME FUNCTION
7-0 TH1.[7:0] Timer 1 MSB.
AUXR
Bit: 7 6 5 4 3 2 1 0
- - - - - - - ALE_OFF
Mnemonic: AUXR Address: 8Eh
W78E054D/W78E052D/W78E051D Data Sheet
- 24 -
BIT NAME FUNCTION
0 ALE_OFF 1: Disenable ALE output
0: Enable ALE output
Watchdog Timer Control Register
Bit: 7 6 5 4 3 2 1 0
ENW CLRW WIDL - - PS2 PS1 PS0
Mnemonic: WDTC Address: 8FH
BIT NAME FUNCTION
7 ENW Enable watch-dog if set.
6 CLRW Clear watch-dog timer and Pre-scalar if set. This flag will be cleared automati-
cally.
5 WIDL If this bit is set, watch-dog is enabled under IDLE mode. If cleared, watch-dog is
disabled under IDLE mode. Default is cleared.
2-0 PS2-0 Watch-dog Pre-scalar timer select. Pre-scalar is selected when set PS2−0 as fol-
lows:
PS2 PS1 PS0 PRE-SCALAR SELECT
0 0 0 2
0 0 1 8
0 1 0 4
0 1 1 16
1 0 0 32
1 0 1 64
1 1 0 128
1 1 1 256
Port 1
Bit: 7 6 5 4 3 2 1 0
P1.7 P1.6 P1.5 P1.4 P1.3 P1.2 P1.1 P1.0
Mnemonic: P1 Address: 90h
BIT NAME FUNCTION
7-0 P1.[7:0] General purpose I/O port. Most instructions will read the port pins in case of a port
read access, however in case of read-modify-write instructions, the port latch is
read.
Serial Port Control
Bit: 7 6 5 4 3 2 1 0
SM0/FE SM1 SM2 REN TB8 RB8 TI RI
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 25 - Revision A10
Mnemonic: SCON Address: 98h
BIT NAME FUNCTION
7 SM0/FE Serial port mode select bit 0 or Framing Error Flag: The SMOD0 bit in PCON
SFR determines whether this bit acts as SM0 or as FE. The operation of SM0 is
described below. When used as FE, this bit will be set to indicate an invalid stop
bit. This bit must be manually cleared in software to clear the FE condition.
6 SM1 Serial Port mode select bit 1. See table below.
5 SM2 Multiple processors communication. Setting this bit to 1 enables the multiproces-
sor communication feature in mode 2 and 3. In mode 2 or 3, if SM2 is set to 1,
then RI will not be activated if the received 9th data bit (RB8) is 0. In mode 1, if
SM2 = 1, then RI will not be activated if a valid stop bit was not received. In
mode 0, the SM2 bit controls the serial port clock. If set to 0, then the serial port
runs at a divide by 12 clock of the oscillator. This gives compatibility with the
standard 8052. When set to 1, the serial clock become divide by 4 of the oscilla-
tor clock. This results in faster synchronous serial communication.
4 REN Receive enable:
0: Disable serial reception.
1: Enable serial reception.
3 TB8 This is the 9th bit to be transmitted in modes 2 and 3. This bit is set and cleared
by software as desired.
2 RB8 In modes 2 and 3 this is the received 9th data bit. In mode 1, if SM2 = 0, RB8 is
the stop bit that was received. In mode 0 it has no function.
1 TI Transmit interrupt flag: This flag is set by hardware at the end of the 8th bit time
in mode 0, or at the beginning of the stop bit in all other modes during serial
transmission. This bit must be cleared by software.
0 RI
Receive interrupt flag: This flag is set by hardware at the end of the 8th bit time
in mode 0, or halfway through the stop bits time in the other modes during serial
reception. However the restrictions of SM2 apply to this bit. This bit can be
cleared only by software.
SM1, SM0: Mode Select bits:
Mode SM0 SM1 Description Length Baud Rate
0 0 0 Synchronous 8 Tclk divided by 4 or 12
1 0 1 Asynchronous 10 Variable
2 1 0 Asynchronous 11 Tclk divided by 32 or 64
3 1 1 Asynchronous 11 Variable
Serial Data Buffer
Bit: 7 6 5 4 3 2 1 0
SBUF.7 SBUF.6 SBUF.5 SBUF.4 SBUF.3 SBUF.2 SBUF.1 SBUF.0
Mnemonic: SBUF Address: 99h
W78E054D/W78E052D/W78E051D Data Sheet
- 26 -
BIT NAME FUNCTION
7~0 SBUF Serial data on the serial port is read from or written to this location. It actually
consists of two separate internal 8-bit registers. One is the receive resister, and
the other is the transmit buffer. Any read access gets data from the receive data
buffer, while write access is to the transmit data buffer.
Port 2
Bit: 7 6 5 4 3 2 1 0
P2.7 P2.6 P2.5 P2.4 P2.3 P2.2 P2.1 P2.0
Mnemonic: P2 Address: A0h
BIT NAME FUNCTION
7-0 P2.[7:0] Port 2 is a bi-directional I/O port with internal pull-ups. This port also provides the
upper address bits for accesses to external memory.
Interrupt Enable
Bit: 7 6 5 4 3 2 1 0
EA - ET2 ES ET1 EX1 ET0 EX0
Mnemonic: IE Address: A8h
BIT NAME FUNCTION
7 EA Global enable. Enable/Disable all interrupts.
6 - Reserved
5 ET2 Enable Timer 2 interrupt.
4 ES Enable Serial Port 0 interrupt.
3 ET1 Enable Timer 1 interrupt.
2 EX1 Enable external interrupt 1.
1 ET0 Enable Timer 0 interrupt.
0 EX0 Enable external interrupt 0.
Port 3
Bit: 7 6 5 4 3 2 1 0
P3.7 P3.6 P3.5 P3.4 P3.3 P3.2 P3.1 P3.0
Mnemonic: P3 Address: B0h
P3.7-0: General purpose Input/Output port. Most instructions will read the port pins in case of a port
read access, however in case of read-modify-write instructions, the port latch is read. These alter-
nate functions are described below:
BIT NAME FUNCTION
7 P3.7 RD
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 27 - Revision A10
6 P3.6 WR
5 P3.5 T1
4 P3.4 T0
3 P3.3 INT1
2 P3.2 INT0
1 P3.1 TX
0 P3.0 RX
Interrupt High Priority
Bit: 7 6 5 4 3 2 1 0
IPH.7 IPH.6 IPH.5 IPH.4 IPH.3 IPH.2 IPH.1 IPH.0
Mnemonic: IPH Address: B7h
BIT NAME FUNCTION
7 IPH.7 1: Interrupt high priority of INT3 is highest priority level.
6 IPH.6 1: Interrupt high priority of INT2 is highest priority level.
5 IPH.5 1: Interrupt high priority of Timer 2 is highest priority level.
4 IPH.4 1: Interrupt high priority of Serial Port 0 is highest priority level.
3 IPH.3 1: Interrupt high priority of Timer 1 is highest priority level.
2 IPH.2 1: Interrupt high priority of External interrupt 1 is highest priority level.
1 IPH.1 1: Interrupt high priority of Timer 0 is highest priority level.
0 IPH.0 1: Interrupt high priority of External interrupt 0 is highest priority level.
Interrupt Priority
Bit: 7 6 5 4 3 2 1 0
- - PT2 PS PT1 PX1 PT0 PX0
Mnemonic: IP Address: B8h
BIT NAME FUNCTION
5 PT2 1: Interrupt priority of Timer 2 is higher priority level.
4 PS 1: Interrupt priority of Serial port 0 is higher priority level.
3 PT1 1: Interrupt priority of Timer 1 is higher priority level.
2 PX1 1: Interrupt priority of External interrupt 1 is higher priority level.
1 PT0 1: Interrupt priority of Timer 0 is higher priority level.
0 PX0 1: Interrupt priority of External interrupt 0 is higher priority level.
W78E054D/W78E052D/W78E051D Data Sheet
- 28 -
EAPAGE ERASE PAGE Operation Modes
Bit: 7 6 5 4 3 2 1 0
- - - - - - EAPG1 EAPG0
Mnemonic: EAPAGE Address: BD
BIT NAME FUNCTION
1 EAPG1 1: To ease PAGE1 when ease command is set. (LDROM)
0 EAPG0 1: To ease PAGE0 when ease command is set. (APROM)
;CPU Clock = 12MHz/12T mode
READ_TIME EQU 1
PROGRAM_TIME EQU 50
ERASE_TIME EQU 5000
Erase_APROM:
mov EAPAGE,#01h ;set EAPAGE is APROM
mov SFRCN,#ERASE_ROM
mov TL0,#LOW (65536-ERASE_TIME)
mov TH0,#HIGH(65536-ERASE_TIME)
setb TR0
mov CHPCON,#00000011b
mov EAPAGE,#00h ;clear EAPAGE
clr TF0
clr TR0
ret
Erase_LDROM:
mov EAPAGE,#02h ;set EAPAGE is LDROM
mov SFRCN,#ERASE_ROM
mov TL0,#LOW (65536-ERASE_TIME)
mov TH0,#HIGH(65536-ERASE_TIME)
setb TR0
mov CHPCON,#00000011b
mov EAPAGE,#00h ;clear EAPAGE
clr TF0
clr TR0
ret
Chip Control
Bit: 7 6 5 4 3 2 1 0
SWRST - - - - -
ISP ENP
Mnemonic: CHPCON Address: BFh
Bit Name Function
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 29 - Revision A10
7 SWRST When this bit is set to 1 and ENP is set to 1. It will enforce microcontroller
reset to initial condition just like power on reset. This action will re-boot the
microcontroller and start to normal operation.
1 ISP The ISP function Select. When this bit is set to 1 and ENP is set to 1. It will run ISP
function.
0 ENP When this bit is set to 1 and SWRST is set to 1. It will enforce microcontrol-
ler reset to initial condition just like power on reset.
When this bit is set to 1 and ISP is set to 1. It will run ISP function
Note1: CHPCON = 0x81, it is Software reset
Note2: CHPCON = 0x03, ISP function is enabled.
External Interrupt Control
Bit: 7 6 5 4 3 2 1 0
PX3 EX3 IE3 IT3 PX2 EX2 IE2 IT2
Mnemonic: XICON Address: C0h
BIT NAME FUNCTION
7 PX3 External interrupt 3 priority is higher if set this bit to 1
6 EX3 Enable External interrupt 3 if set this bit to 1
5 IE3 If IT3 = 1, IE3 is set/cleared automatically by hardware when interrupt is de-
tected/serviced
4 IT3 External interrupt 3 is falling-edge/low-level triggered when this bit is set/cleared
by software
3 PX2 External interrupt 2 priority is higher if set this to 1
2 EX2 Enable External interrupt 2 if set this bit to 1
1 IE2 If IT2 = 1, IE2 is set/cleared automatically by hardware when interrupt is de-
tected/serviced
0 IT2 External interrupt 2 is falling-edge/low-level triggered when this bit is set/cleared
by software
SFR program of address low
Bit: 7 6 5 4 3 2 1 0
SFRAL.7 SFRAL.6 SFRAL.5 SFRAL.4 SFRAL.3 SFRAL.2 SFRAL.1 SFRAL.0
Mnemonic: SFRAL Address: C4h
BIT NAME FUNCTION
7-0 SFRAL.[7:0] The programming address of on-chip flash memory in programming mode.
SFRFAL contains the low-order byte of address.
SFR program of address high
Bit: 7 6 5 4 3 2 1 0
W78E054D/W78E052D/W78E051D Data Sheet
- 30 -
SFRAH.7 SFRAH.6 SFRAH.5 SFRAH.4 SFRAH.3 SFRAH.2 SFRAH.1 SFRAH.0
Mnemonic: SFRAH Address: C5h
BIT NAME FUNCTION
7-0 SFRAH.[7:0] The programming address of on-chip flash memory in programming mode.
SFRFAH contains the high-order byte of address.
SFR program For Data
Bit: 7 6 5 4 3 2 1 0
SFRFD.7 SFRFD.6 SFRFD.5 SFRFD.4 SFRFD.3 SFRFD.2 SFRFD.1 SFRFD.0
Mnemonic: SFRFD Address: C6h
BIT NAME FUNCTION
7-0 SFRFD.[7:0] The programming data for on-chip flash memory in programming mode.
SFR for Program Control
Bit: 7 6 5 4 3 2 1 0
- OEN CEN CTRL3 CTRL2 CTRL1 CTRL0
Mnemonic: SFRCN Address: C7h
BIT NAME FUNCTION
5 OEN FLASH EPROM output enable.
4 CEN FLASH EPROM chip enable.
3-0 CTRL[3:0] CTRL[3:0]: The flash control signals
Mode OEN CEN CTRL<3:0> SFRAH, SFRAL SFRFD
Flash Standby 1 1 X X X
Read Company ID 0 0 1011 0FFh, 0FFh Data out
Read Device ID High 0 0 1100 0FFh, 0FFh Data out
Read Device ID Low 1 0 1100 0FFh, 0FEh Data out
Erase APROM 1 0 0010 X X
Erase Verify APROM 0 0 1001 Address in Data out
Program APROM 1 0 0001 Address in Data in
Program Verify APROM 0 0 1010 Address in Data out
Read APROM 0 0 0000 Address in Data out
Timer 2 Control
Bit: 7 6 5 4 3 2 1 0
TF2 EXF2 RCLK TCLK EXEN2 TR2 CT/2
CP RL/2
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 31 - Revision A10
Mnemonic: T2CON Address: C8h
BIT NAME FUNCTION
7 TF2 Timer 2 overflow flag: This bit is set when Timer 2 overflows. It is also set
when the count is equal to the capture register in down count mode. It can be
set only if RCLK and TCLK are both 0. It is cleared only by software. Software
can also set or clear this bit.
6 EXF2 Timer 2 External Flag: A negative transition on the T2EX pin (P1.1) or timer 2
overflow will cause this flag to set based on the CP RL/2
, EXEN2 and DCEN
bits. If set by a negative transition, this flag must be cleared by software. Set-
ting this bit in software or detection of a negative transition on T2EX pin will
force a timer interrupt if enabled.
5 RCLK Receive Clock Flag: This bit determines the serial port 0 time-base when re-
ceiving data in serial modes 1 or 3. If it is 0, then timer 1 overflow is used for
baud rate generation, otherwise timer 2 overflow is used. Setting this bit forces
timer 2 in baud rate generator mode.
4 TCLK Transmit Clock Flag: This bit determines the serial port 0 time-base when
transmitting data in modes 1 and 3. If it is set to 0, the timer 1 overflow is used
to generate the baud rate clock otherwise timer 2 overflow is used. Setting this
bit forces timer 2 in baud rate generator mode.
3 EXEN2 Timer 2 External Enable. This bit enables the capture/reload function on the
T2EX pin if Timer 2 is not generating baud clocks for the serial port. If this bit
is 0, then the T2EX pin will be ignored, otherwise a negative transition de-
tected on the T2EX pin will result in capture or reload.
2 TR2 Timer 2 Run Control. This bit enables/disables the operation of timer 2. Clear-
ing this bit will halt the timer 2 and preserve the current count in TH2, TL2.
1 CT/2
Counter/Timer Select. This bit determines whether timer 2 will function as a
timer or a counter. Independent of this bit, the timer will run at 2 clocks per tick
when used in baud rate generator mode.
0 CP RL/2
Capture/Reload Select. This bit determines whether the capture or reload
function will be used for timer 2. If either RCLK or TCLK is set, this bit will be
ignored and the timer will function in an auto-reload mode following each over-
flow. If the bit is 0 then auto-reload will occur when timer 2 overflows or a fal-
ling edge is detected on T2EX pin if EXEN2 = 1. If this bit is 1, then timer 2
captures will occur when a falling edge is detected on T2EX pin if EXEN2 =
1.
Timer 2 Mode Control
Bit: 7 6 5 4 3 2 1 0
- - - - - - DCEN
Mnemonic: T2MOD Address: C9h
BIT NAME FUNCTION
0 DCEN Down Count Enable: This bit, in conjunction with the T2EX pin, controls the
direction that timer 2 counts in 16-bit auto-reload mode.
W78E054D/W78E052D/W78E051D Data Sheet
- 32 -
Timer 2 Capture LSB
Bit: 7 6 5 4 3 2 1 0
RCAP2L.7 RCAP2L.6 RCAP2L.5 RCAP2L.4 RCAP2L.3 RCAP2L.2 RCAP2L.1 RCAP2L.0
Mnemonic: RCAP2L Address: CAh
BIT NAME FUNCTION
7-0 RCAP2L.[7:0] This register is used to capture the TL2 value when a timer 2 is configured in
capture mode. RCAP2L is also used as the LSB of a 16-bit reload value
when timer 2 is configured in auto-reload mode.
Timer 2 Capture MSB
Bit: 7 6 5 4 3 2 1 0
RCAP2h.7 RCAP2h.6 RCAP2h.5 RCAP2h.4 RCAP2h.3 RCAP2h.2 RCAP2h.1 RCAP2h.0
Mnemonic: RCAP2H Address: CBh
BIT NAME FUNCTION
7-0 RCAP2H.[7:0] This register is used to capture the TH2 value when a timer 2 is configured in
capture mode. RCAP2H is also used as the MSB of a 16-bit reload value
when timer 2 is configured in auto-reload mode.
Timer 2 LSB
Bit: 7 6 5 4 3 2 1 0
TL2.7 TL2.6 TL2.5 TL2.4 TL2.3 TL2.2 TL2.1 TL2.0
Mnemonic: TL2 Address: CCh
BIT NAME FUNCTION
7-0 TL2.[7:0] Timer 2 LSB
Timer 2 MSB
Bit: 7 6 5 4 3 2 1 0
TH2.7 TH2.6 TH2.5 TH2.4 TH2.3 TH2.2 TH2.1 TH2.0
Mnemonic: TH2 Address: CDh
BIT NAME FUNCTION
7-0 TH2.[7:0] Timer 2 MSB
Program Status Word
Bit: 7 6 5 4 3 2 1 0
CY AC F0 RS1 RS0 OV F1 P
Mnemonic: PSW Address: D0h
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 33 - Revision A10
BIT NAME FUNCTION
7 CY Carry flag:
Set for an arithmetic operation which results in a carry being generated from the
ALU. It is also used as the accumulator for the bit operations.
6 AC Auxiliary carry:
Set when the previous operation resulted in a carry from the high order nibble.
5 F0 User flag 0:
The General purpose flag that can be set or cleared by the user.
4 RS1 Register bank select bits:
3 RS0 Register bank select bits:
2 OV Overflow flag:
Set when a carry was generated from the seventh bit but not from the 8th bit as a
result of the previous operation, or vice-versa.
1 F1 User Flag 1:
The General purpose flag that can be set or cleared by the user by software.
0 P Parity flag:
Set/cleared by hardware to indicate odd/even number of 1’s in the accumulator.
Port 4
Bit: 7 6 5 4 3 2 1 0
- - - - P4.3 P4.2 P4.1 P4.0
Mnemonic: P4 Address: D8h
Another bit-addressable port P4 is also available and only 4 bits (P4<3:0>) can be used. This port ad-
dress is located at 0D8H with the same function as that of port P1, except the P4.3 and P4.2 are alter-
native function pins. It can be used as general I/O pins or external interrupt input sources (INT2 ,
INT3 ).
ACCUMULATOR
Bit: 7 6 5 4 3 2 1 0
ACC.7 ACC.6 ACC.5 ACC.4 ACC.3 ACC.2 ACC.1 ACC.0
Mnemonic: ACC Address: E0h
Bit Name Function
7-0 ACC The A or ACC register is the standard 8052 accumulator.
B Register
Bit: 7 6 5 4 3 2 1 0
B.7 B.6 B.5 B.4 B.3 B.2 B.1 B.0
Mnemonic: B Address: F0h
Bit Name Function
W78E054D/W78E052D/W78E051D Data Sheet
- 34 -
7-0 B The B register is the standard 8052 register that serves as a second accumulator.
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 35 - Revision A10
10 INSTRUCTION
The W78E054D/W78E052D/W78E051D series execute all the instructions of the standard 8052 fam-
ily. The operations of these instructions, as well as their effects on flag and status bits, are exactly the
same.
Op-code HEX Code Bytes W78E054D/W78E052D/W78E051D
series Clock cycles
NOP 00 1 12
ADD A, R0 28 1 12
ADD A, R1 29 1 12
ADD A, R2 2A 1 12
ADD A, R3 2B 1 12
ADD A, R4 2C 1 12
ADD A, R5 2D 1 12
ADD A, R6 2E 1 12
ADD A, R7 2F 1 12
ADD A, @R0 26 1 12
ADD A, @R1 27 1 12
ADD A, direct 25 2 12
ADD A, #data 24 2 12
ADDC A, R0 38 1 12
ADDC A, R1 39 1 12
ADDC A, R2 3A 1 12
ADDC A, R3 3B 1 12
ADDC A, R4 3C 1 12
ADDC A, R5 3D 1 12
ADDC A, R6 3E 1 12
ADDC A, R7 3F 1 12
ADDC A, @R0 36 1 12
ADDC A, @R1 37 1 12
ADDC A, direct 35 2 12
ADDC A, #data 34 2 12
SUBB A, R0 98 1 12
SUBB A, R1 99 1 12
SUBB A, R2 9A 1 12
SUBB A, R3 9B 1 12
W78E054D/W78E052D/W78E051D Data Sheet
- 36 -
Op-code HEX Code Bytes W78E054D/W78E052D/W78E051D
series Clock cycles
SUBB A, R4 9C 1 12
SUBB A, R5 9D 1 12
SUBB A, R6 9E 1 12
SUBB A, R7 9F 1 12
SUBB A, @R0 96 1 12
SUBB A, @R1 97 1 12
SUBB A, direct 95 2 12
SUBB A, #data 94 2 12
INC A 04 1 12
INC R0 08 1 12
INC R1 09 1 12
INC R2 0A 1 12
INC R3 0B 1 12
INC R4 0C 1 12
INC R5 0D 1 12
INC R6 0E 1 12
INC R7 0F 1 12
INC @R0 06 1 12
INC @R1 07 1 12
INC direct 05 2 12
INC DPTR A3 1 24
DEC A 14 1 12
DEC R0 18 1 12
DEC R1 19 1 12
DEC R2 1A 1 12
DEC R3 1B 1 12
DEC R4 1C 1 12
DEC R5 1D 1 12
DEC R6 1E 1 12
DEC R7 1F 1 12
DEC @R0 16 1 12
DEC @R1 17 1 12
DEC direct 15 2 12
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 37 - Revision A10
Op-code HEX Code Bytes W78E054D/W78E052D/W78E051D
series Clock cycles
MUL AB A4 1 48
DIV AB 84 1 48
DA A D4 1 12
ANL A, R0 58 1 12
ANL A, R1 59 1 12
ANL A, R2 5A 1 12
ANL A, R3 5B 1 12
ANL A, R4 5C 1 12
ANL A, R5 5D 1 12
ANL A, R6 5E 1 12
ANL A, R7 5F 1 12
ANL A, @R0 56 1 12
ANL A, @R1 57 1 12
ANL A, direct 55 2 12
ANL A, #data 54 2 12
ANL direct, A 52 2 12
ANL direct, #data 53 3 24
ORL A, R0 48 1 12
ORL A, R1 49 1 12
ORL A, R2 4A 1 12
ORL A, R3 4B 1 12
ORL A, R4 4C 1 12
ORL A, R5 4D 1 12
ORL A, R6 4E 1 12
ORL A, R7 4F 1 12
ORL A, @R0 46 1 12
ORL A, @R1 47 1 12
ORL A, direct 45 2 12
ORL A, #data 44 2 12
ORL direct, A 42 2 12
ORL direct, #data 43 3 24
XRL A, R0 68 1 12
W78E054D/W78E052D/W78E051D Data Sheet
- 38 -
Op-code HEX Code Bytes W78E054D/W78E052D/W78E051D
series Clock cycles
XRL A, R1 69 1 12
XRL A, R2 6A 1 12
XRL A, R3 6B 1 12
XRL A, R4 6C 1 12
XRL A, R5 6D 1 12
XRL A, R6 6E 1 12
XRL A, R7 6F 1 12
XRL A, @R0 66 1 12
XRL A, @R1 67 1 12
XRL A, direct 65 2 12
XRL A, #data 64 2 12
XRL direct, A 62 2 12
XRL direct, #data 63 3 24
CLR A E4 1 12
CPL A F4 1 12
RL A 23 1 12
RLC A 33 1 12
RR A 03 1 12
RRC A 13 1 12
SWAP A C4 1 12
MOV A, R0 E8 1 12
MOV A, R1 E9 1 12
MOV A, R2 EA 1 12
MOV A, R3 EB 1 12
MOV A, R4 EC 1 12
MOV A, R5 ED 1 12
MOV A, R6 EE 1 12
MOV A, R7 EF 1 12
MOV A, @R0 E6 1 12
MOV A, @R1 E7 1 12
MOV A, direct E5 2 12
MOV A, #data 74 2 12
MOV R0, A F8 1 12
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 39 - Revision A10
Op-code HEX Code Bytes W78E054D/W78E052D/W78E051D
series Clock cycles
MOV R1, A F9 1 12
MOV R2, A FA 1 12
MOV R3, A FB 1 12
MOV R4, A FC 1 12
MOV R5, A FD 1 12
MOV R6, A FE 1 12
MOV R7, A FF 1 12
MOV R0, direct A8 2 24
MOV R1, direct A9 2 24
MOV R2, direct AA 2 24
MOV R3, direct AB 2 24
MOV R4, direct AC 2 24
MOV R5, direct AD 2 24
MOV R6, direct AE 2 24
MOV R7, direct AF 2 24
MOV R0, #data 78 2 12
MOV R1, #data 79 2 12
MOV R2, #data 7A 2 12
MOV R3, #data 7B 2 12
MOV R4, #data 7C 2 12
MOV R5, #data 7D 2 12
MOV R6, #data 7E 2 12
MOV R7, #data 7F 2 12
MOV @R0, A F6 1 12
MOV @R1, A F7 1 12
MOV @R0, direct A6 2 24
MOV @R1, direct A7 2 24
MOV @R0, #data 76 2 12
MOV @R1, #data 77 2 12
MOV direct, A F5 2 12
MOV direct, R0 88 2 24
MOV direct, R1 89 2 24
W78E054D/W78E052D/W78E051D Data Sheet
- 40 -
Op-code HEX Code Bytes W78E054D/W78E052D/W78E051D
series Clock cycles
MOV direct, R2 8A 2 24
MOV direct, R3 8B 2 24
MOV direct, R4 8C 2 24
MOV direct, R5 8D 2 24
MOV direct, R6 8E 2 24
MOV direct, R7 8F 2 24
MOV direct, @R0 86 2 24
MOV direct, @R1 87 2 24
MOV direct, direct 85 3 24
MOV direct, #data 75 3 24
MOV DPTR, #data 16 90 3 24
MOVC A, @A+DPTR 93 1 24
MOVC A, @A+PC 83 1 24
MOVX A, @R0 E2 1 24
MOVX A, @R1 E3 1 24
MOVX A, @DPTR E0 1 24
MOVX @R0, A F2 1 24
MOVX @R1, A F3 1 24
MOVX @DPTR, A F0 1 24
PUSH direct C0 2 24
POP direct D0 2 24
XCH A, R0 C8 1 12
XCH A, R1 C9 1 12
XCH A, R2 CA 1 12
XCH A, R3 CB 1 12
XCH A, R4 CC 1 12
XCH A, R5 CD 1 12
XCH A, R6 CE 1 12
XCH A, R7 CF 1 12
XCH A, @R0 C6 1 12
XCH A, @R1 C7 1 12
XCHD A, @R0 D6 1 12
XCHD A, @R1 D7 1 12
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 41 - Revision A10
Op-code HEX Code Bytes W78E054D/W78E052D/W78E051D
series Clock cycles
XCH A, direct C5 2 24
CLR C C3 1 12
CLR bit C2 2 12
SETB C D3 1 12
SETB bit D2 2 12
CPL C B3 1 12
CPL bit B2 2 12
ANL C, bit 82 2 24
ANL C, /bit B0 2 24
ORL C, bit 72 2 24
ORL C, /bit A0 2 24
MOV C, bit A2 2 12
MOV bit, C 92 2 24
ACALL addr11
71, 91, B1,
11, 31, 51,
D1, F1
2 24
LCALL addr16 12 3 24
RET 22 1 24
RETI 32 1 24
AJMP ADDR11
01, 21, 41,
61, 81, A1,
C1, E1
2 24
LJMP addr16 02 3 24
JMP @A+DPTR 73 1 24
SJMP rel 80 2 24
JZ rel 60 2 24
JNZ rel 70 2 24
JC rel 40 2 24
JNC rel 50 2 24
JB bit, rel 20 3 24
JNB bit, rel 30 3 24
JBC bit, rel 10 3 24
CJNE A, direct, rel B5 3 24
CJNE A, #data, rel B4 3 24
W78E054D/W78E052D/W78E051D Data Sheet
- 42 -
Op-code HEX Code Bytes W78E054D/W78E052D/W78E051D
series Clock cycles
CJNE @R0, #data, rel B6 3 24
CJNE @R1, #data, rel B7 3 24
CJNE R0, #data, rel B8 3 24
CJNE R1, #data, rel B9 3 24
CJNE R2, #data, rel BA 3 24
CJNE R3, #data, rel BB 3 24
CJNE R4, #data, rel BC 3 24
CJNE R5, #data, rel BD 3 24
CJNE R6, #data, rel BE 3 24
CJNE R7, #data, rel BF 3 24
DJNZ R0, rel D8 2 24
DJNZ R1, rel D9 2 24
DJNZ R5, rel DD 2 24
DJNZ R2, rel DA 2 24
DJNZ R3, rel DB 2 24
DJNZ R4, rel DC 2 24
DJNZ R6, rel DE 2 24
DJNZ R7, rel DF 2 24
DJNZ direct, rel D5 3 24
Table 10-1: Instruction Set for W78E054D/W78E052D/W78E051D
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 43 - Revision A10
10.1 Instruction Timing
A machine cycle consists of a sequence of 6 states, numbered S1 through S6. Each state time lasts
for two oscillator periods. Thus a machine cycle takes 12 oscillator periods or 1us if the oscillator fre-
quency is 12MHz.
Each state is divided into a Phase 1 half and a Phase 2 half. The fetch/execute sequences in states
and phases for various kinds of instructions. Normally two program fetches are generated during each
machine cycle, even if the instruction being executed doesn’t require it. If the instruction being exe-
cuted doesn’t need more code bytes, the CPU simply ignores the extra fetch, and the Program
Counter is not incremented. Execution of a one-cycle instruction begins during State 1 of the machine
cycle, when the OPCODE is latched into the Instruction Register. A second fetch occurs during S4 of
the same machine cycle. Execution is complete at the end of State 6 of this machine cycle.
The MOVX instructions take two machine cycles to execute. No program fetch is generated during the
second cycle of a MOVX instruction. This is the only time program fetches are skipped. The
fetch/execute sequence for MOVX instructions.
The fetch/execute sequences are the same whether the Program Memory is internal or external to the
chip. Execution times do not depend on whether the Program Memory is internal or external.
The signals and timing involved in program fetches when the Program Memory is external. If Program
Memory is external, then the Program Memory read strobe PSEN is normally activated twice per ma-
chine cycle. If an access to external Data Memory occurs, two PSEN pulse are skipped, because the
address and data bus are being used for the Data Memory access. Note that a Data Memory bus cy-
cle takes twice as much time as a Program Memory bus cycle.
W78E054D/W78E052D/W78E051D Data Sheet
- 44 -
11 POWER MANAGEMENT
The W78E054D/W78E052D/W78E051D has several features that help the user to control the power
consumption of the device. The power saved features have basically the POWER DOWN mode and
the IDLE mode of operation.
11.1 Idle Mode
The user can put the device into idle mode by writing 1 to the bit PCON.0. The instruction that sets the
idle bit is the last instruction that will be executed before the device goes into Idle Mode. In the Idle
mode, the clock to the CPU is halted, but not to the Interrupt, Timer, Watchdog timer and Serial port
blocks. This forces the CPU state to be frozen; the Program counter, the Stack Pointer, the Program
Status Word, the Accumulator and the other registers hold their contents. The port pins hold the logi-
cal states they had at the time Idle was activated. The Idle mode can be terminated in two ways. Since
the interrupt controller is still active, the activation of any enabled interrupt can wake up the processor.
This will automatically clear the Idle bit, terminate the Idle mode, and the Interrupt Service Routine
(ISR) will be executed. After the ISR, execution of the program will continue from the instruction which
put the device into Idle mode.
The Idle mode can also be exited by activating the reset. The device can put into reset either by apply-
ing a high on the external RST pin, a Power on reset condition or a Watchdog timer reset. The exter-
nal reset pin has to be held high for at least two machine cycles i.e. 24 clock periods to be recognized
as a valid reset. In the reset condition the program counter is reset to 0000h and all the SFRs are set
to the reset condition. Since the clock is already running there is no delay and execution starts imme-
diately.
11.2 Po wer Down Mode
The device can be put into Power Down mode by writing 1 to bit PCON.1. The instruction that does
this will be the last instruction to be executed before the device goes into Power Down mode. In the
Power Down mode, all the clocks are stopped and the device comes to a halt. All activity is completely
stopped and the power consumption is reduced to the lowest possible value. The port pins output the
values held by their respective SFRs.
The W78E054D/W78E052D/W78E051D will exit the Power Down mode with a reset or by an external
interrupt pin enabled as level detects. An external reset can be used to exit the Power down state. The
high on RST pin terminates the Power Down mode, and restarts the clock. The program execution will
restart from 0000h. In the Power down mode, the clock is stopped, so the Watchdog timer cannot be
used to provide the reset to exit Power down mode.
The W78E054D/W78E052D/W78E051D can be woken from the Power Down mode by forcing an ex-
ternal interrupt pin activated, provided the corresponding interrupt is enabled, while the global en-
able(EA) bit is set and the external input has been set to a level detect mode. If these conditions are
met, then the high level on the external pin re-starts the oscillator. Then device executes the interrupt
service routine for the corresponding external interrupt. After the interrupt service routine is completed,
the program execution returns to the instruction after one which put the device into Power Down mode
and continues from there.
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 45 - Revision A10
12 RESET CONDITIONS
The user has several hardware related options for placing the W78E054D/W78E052D/W78E051D into
reset condition. In general, most register bits go to their reset value irrespective of the reset condition,
but there are a few flags whose state depends on the source of reset. The user can use these flags to
determine the cause of reset using software.
12.1 Sources of rese t
12.1.1 External Reset
The device continuously samples the RST pin at state S5P2 of every machine cycle. Therefore the
RST pin must be held for at least 2 machine cycles (24 clock cycles) to ensure detection of a valid
RST high. The reset circuitry then synchronously applies the internal reset signal. Thus the reset is a
synchronous operation and requires the clock to be running to cause an external reset. For more tim-
ing information, please reference the character 21.4.5 (Page 77).
Once the device is in reset condition, it will remain so as long as RST is 1. Even after RST is deacti-
vated, the device will continue to be in reset state for up to two machine cycles, and then begin pro-
gram execution from 0000h. There is no flag associated with the external reset condition.
12.1.2 Software Reset
The W78E054D/W78E052D/W78E051D offers a software reset to switch back to the APROM. Setting
CHPCON bits 0, 1 and 7 to logic-1 creates software reset to reset the CPU to start APROM code.
Note: Software Reset only LDROM jump to APROM, APROM can’t software reset to LDROM.
12.1.3 Watchdog Timer Reset
The Watchdog timer is a free running timer with programmable time-out intervals. The user can clear
the watchdog timer at any time, causing it to restart the count. When the time-out interval is reached
an interrupt flag is set. If the Watchdog reset is enabled and the watchdog timer is not cleared, the
watchdog timer will generate a reset. This places the device into the reset condition. The reset condi-
tion is maintained by hardware for two machine cycles. Once the reset is removed the device will be-
gin execution from 0000h.
12.2 Reset State
Most of the SFRs and registers on the device will go to the same condition in the reset state. The Pro-
gram Counter is forced to 0000h and is held there as long as the reset condition is applied. However,
the reset state does not affect the on-chip RAM. The data in the RAM will be preserved during the re-
set. However, the stack pointer is reset to 07h, and therefore the stack contents will be lost. The RAM
contents will be lost if the VDD falls below approximately 2V, as this is the minimum voltage level re-
quired for the RAM to operate normally. Therefore after a first time power on reset the RAM contents
will be indeterminate. During a power fail condition, if the power falls below 2V, the RAM contents are
lost.
After a reset most SFRs are cleared. Interrupts and Timers are disabled. The Watchdog timer is dis-
abled if the reset source was a POR. The port SFRs has 0FFh written into them which puts the port
pins in a high state.
W78E054D/W78E052D/W78E051D Data Sheet
- 46 -
13 INTERRUPTS
The W78E054D/W78E052D/W78E051D has a 4 priority level interrupt structure with 8 interrupt
sources. Each of the interrupt sources has an individual priority bit, flag, interrupt vector and enable
bit. In addition, the interrupts can be globally enabled or disabled.
13.1 Interrupt Sources
The External Interrupts INT0 and INT1 can be either edge triggered or level triggered, depending on
bits IT0 and IT1. The bits IE0 and IE1 in the TCON register are the flags which are checked to gener-
ate the interrupt. In the edge triggered mode, the INTx inputs are sampled in every machine cycle. If
the sample is high in one cycle and low in the next, then a high to low transition is detected and the
interrupts request flag IEx in TCON o is set. The flag bit requests the interrupt. Since the external in-
terrupts are sampled every machine cycle, they have to be held high or low for at least one complete
machine cycle. The IEx flag is automatically cleared when the service routine is called. If the level trig-
gered mode is selected, then the requesting source has to hold the pin low till the interrupt is serviced.
The IEx flag will not be cleared by the hardware on entering the service routine. If the interrupt contin-
ues to be held low even after the service routine is completed, then the processor may acknowledge
another interrupt request from the same source. Note that the external interrupts INT2 and INT3 . By
default, the individual interrupt flag corresponding to external interrupt 2 to 3 must be cleared manually
by software.
The Timer 0 and 1 Interrupts are generated by the TF0 and TF1 flags. These flags are set by the over-
flow in the Timer 0 and Timer 1. The TF0 and TF1 flags are automatically cleared by the hardware
when the timer interrupt is serviced. The Timer 2 interrupt is generated by a logical OR of the TF2 and
the EXF2 flags. These flags are set by overflow or capture/reload events in the timer 2 operation. The
hardware does not clear these flags when a timer 2 interrupt is executed. Software has to resolve the
cause of the interrupt between TF2 and EXF2 and clear the appropriate flag.
The Serial block can generate interrupts on reception or transmission. There are two interrupt sources
from the Serial block, which are obtained by the RI and TI bits in the SCON SFR, These bits are not
automatically cleared by the hardware, and the user will have to clear these bits using software.
All the bits that generate interrupts can be set or reset by hardware, and thereby software initiated in-
terrupts can be generated. Each of the individual interrupts can be enabled or disabled by setting or
clearing a bit in the IE SFR. IE also has a global enable/disable bit EA, which can be cleared to dis-
able all the interrupts, at once.
Source Vector Address Source Vector Address
External Interrupt 0 0003h Timer 0 Overflow 000Bh
External Interrupt 1 0013h Timer 1 Overflow 001Bh
Serial Port 0023h Timer 2 Overflow 002Bh
External Interrupt 2 0033h External Interrupt 3 003Bh
Table 13–1 W78E054D/W78E052D/W78E051D interrupt vector table
13.2 Priority Level Structure
There are 4 priority levels for the interrupts high, low. Naturally, a higher priority interrupt cannot be
interrupted by a lower priority interrupt. However there exists a pre-defined hierarchy amongst the in-
terrupts themselves. This hierarchy comes into play when the interrupt controller has to resolve simul-
taneous requests having the same priority level. This hierarchy is defined as shown on Table.
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 47 - Revision A10
PRIORITY BITS
IPH IP/
XICON.7/
XICON.3
INTERRUPT PRIORITY LEVEL
0 0 Level 0 (lowest priority)
0 1 Level 1
1 0 Level 2
1 1 Level 3 (highest priority)
The interrupt flags are sampled every machine cycle. In the same machine cycle, the sampled inter-
rupts are polled and their priority is resolved. If certain conditions are met then the hardware will exe-
cute an internally generated LCALL instruction which will vector the process to the appropriate inter-
rupt vector address. The conditions for generating the LCALL are;
1. An interrupt of equal or higher priority is not currently being serviced.
2. The current polling cycle is the last machine cycle of the instruction currently being executed.
3. The current instruction does not involve a write to IE, IP, IPH, XICON registers and is not a RETI.
If any of these conditions are not met, then the LCALL will not be generated. The polling cycle is re-
peated every machine cycle, with the interrupts sampled in the same machine cycle. If an interrupt flag
is active in one cycle but not responded to, and is not active when the above conditions are met, the
denied interrupt will not be serviced. This means that active interrupts are not remembered; every poll-
ing cycle is new.
The processor responds to a valid interrupt by executing an LCALL instruction to the appropriate ser-
vice routine. This may or may not clear the flag which caused the interrupt. In case of Timer interrupts,
the TF0 or TF1 flags are cleared by hardware whenever the processor vectors to the appropriate timer
service routine. In case of external interrupt, /INT0 and /INT1, the flags are cleared only if they are
edge triggered. In case of Serial interrupts, the flags are not cleared by hardware. In the case of Timer
2 interrupt, the flags are not cleared by hardware. The hardware LCALL behaves exactly like the soft-
ware LCALL instruction. This instruction saves the Program Counter contents onto the Stack, but does
not save the Program Status Word PSW. The PC is reloaded with the vector address of that interrupt
which caused the LCALL. These address of vector for the different sources are as shown on the below
table. The vector table is not evenly spaced; this is to accommodate future expansions to the device
family.
Execution continues from the vectored address till an RETI instruction is executed. On execution of
the RETI instruction the processor pops the Stack and loads the PC with the contents at the top of the
stack. The user must take care that the status of the stack is restored to what is after the hardware
LCALL, if the execution is to return to the interrupted program. The processor does not notice anything
if the stack contents are modified and will proceed with execution from the address put back into PC.
Note that a RET instruction would perform exactly the same process as a RETI instruction, but it
would not inform the Interrupt Controller that the interrupt service routine is completed, and would
leave the controller still thinking that the service routine is underway.
Each interrupt source can be individually enabled or disabled by setting or clearing a bit in registers IE.
The IE register also contains a global disable bit, EA, which disables all interrupts at once.
W78E054D/W78E052D/W78E051D Data Sheet
- 48 -
Each interrupt source can be individually programmed to one of 2 priority levels by setting or clearing
bits in the IP registers. An interrupt service routine in progress can be interrupted by a higher priority
interrupt, but not by another interrupt of the same or lower priority. The highest priority interrupt service
cannot be interrupted by any other interrupt source. So, if two requests of different priority levels are
received simultaneously, the request of higher priority level is serviced.
If requests of the same priority level are received simultaneously, an internal polling sequence deter-
mines which request is serviced. This is called the arbitration ranking. Note that the arbitration ranking
is only used to resolve simultaneous requests of the same priority level.
Table below summarizes the interrupt sources, flag bits, vector addresses, enable bits, priority bits,
arbitration ranking, and External interrupt may wake up the CPU from Power Down mode.
Source Flag Vector
address Enable bit Interrupt
Priority F lag cleared
by Arbitration
ranking Power-
down
wakeup
External Interrupt 0 IE0 0003H EX0 (IE.0) IPH.0, IP.0 Hardware,
software
1(highest) Yes
Timer 0 Overflow TF0 000BH ET0 (IE.1) IPH.1, IP.1 Hardware,
software
2 No
External Interrupt 1 IE1 0013H EX1 (IE.2) IPH.2, IP.2 Hardware,
software
3 Yes
Timer 1 Overflow TF1 001BH ET1 (IE.3) IPH.3, IP.3 Hardware,
software
4 No
Serial Port RI +
TI
0023H ES (IE.4) IPH.4, IP.4 Software 5 No
Timer 2 Over-
flow/Match
TF2 002BH ET2 (IE.5) IPH.5, IP.5 Software 6 No
External Interrupt 2 IE2 0033H EX2
(XICON.2)
IPH.6,
PX2
Hardware,
software
7 Yes
External Interrupt 3 IE3 003BH EX3
(XICON.6)
IPH.7,
PX3
Hardware,
software
8(lowest) Yes
Table 13–2 Summary of interrupt sources
13.3 Interrupt Response Time
The response time for each interrupt source depends on several factors, such as the nature of the in-
terrupt and the instruction underway. In the case of external interrupts INT0 and INT1 , they are sam-
pled at S5P2 of every machine cycle and then their corresponding interrupt flags IEx will be set or re-
set. The Timer 0 and 1 overflow flags are set at C3 of the machine cycle in which overflow has oc-
curred. These flag values are polled only in the next machine cycle. If a request is active and all three
conditions are met, then the hardware generated LCALL is executed. This LCALL itself takes four ma-
chine cycles to be completed. Thus there is a minimum time of five machine cycles between the inter-
rupt flag being set and the interrupt service routine being executed.
A longer response time should be anticipated if any of the three conditions are not met. If a higher or
equal priority is being serviced, then the interrupt latency time obviously depends on the nature of the
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 49 - Revision A10
service routine currently being executed. If the polling cycle is not the last machine cycle of the instruc-
tion being executed, then an additional delay is introduced. The maximum response time (if no other
interrupt is in service) occurs if the device is performing a write to IE, IP, IPH and then executes a
MUL or DIV instruction.
13.4 Interrupt Inputs
Since the external interrupt pins are sampled once each machine cycle, an input high or low should
hold for at least one machine cycle to ensure proper sampling. If the external interrupt is high for at
least one machine cycle, and then hold it low for at least one machine cycle. This is to ensure that the
transition is seen and that interrupt request flag IEn is set. IEn is automatically cleared by the CPU
when the service routine is called.
If the external interrupt is level-activated, the external source must hold the request active until the
requested interrupt is actually generated. If the external interrupt is still asserted when the interrupt
service routine is completed another interrupt will be generated. It is not necessary to clear the inter-
rupt flag IEn when the interrupt is level sensitive, it simply tracks the input pin level.
If an external interrupt is enabled when the W78E054D/W78E052D/W78E051D is put into Power
Down or Idle mode, the interrupt will cause the processor to wake up and resume operation. Refer to
the section on Power Reduction Modes for details.
W78E054D/W78E052D/W78E051D Data Sheet
- 50 -
14 PROGRAMMABLE TIMERS/COUNTERS
The W78E054D/W78E052D/W78E051D series have Three 16-bit programmable timer/counters. A
machine cycle equals 12 or 6 oscillator periods, and it depends on 12T mode or 6T mode that the user
configured this device.
14.1 Timer/Counters 0 & 1
W78E054D/W78E052D/W78E051D has two 16-bit Timer/Counters. Each of these Timer/Counters
has two 8 bit registers which form the 16 bit counting register. For Timer/Counter 0 they are TH0, the
upper 8 bits register, and TL0, the lower 8 bit register. Similarly Timer/Counter 1 has two 8 bit regis-
ters, TH1 and TL1. The two can be configured to operate either as timers, counting machine cycles or
as counters counting external inputs.
When configured as a "Timer", the timer counts clock cycles. The timer clock can be programmed to
be thought of as 1/12 of the system clock. In the "Counter" mode, the register is incremented on the
falling edge of the external input pin, T0 in case of Timer 0, and T1 for Timer 1. The T0 and T1 inputs
are sampled in every machine cycle at C4. If the sampled value is high in one machine cycle and low
in the next, then a valid high to low transition on the pin is recognized and the count register is incre-
mented. Since it takes two machine cycles to recognize a negative transition on the pin, the maximum
rate at which counting will take place is 1/24 of the master clock frequency. In either the "Timer" or
"Counter" mode, the count register will be updated at C3. Therefore, in the "Timer" mode, the recog-
nized negative transition on pin T0 and T1 can cause the count register value to be updated only in
the machine cycle following the one in which the negative edge was detected.
The "Timer" or "Counter" function is selected by the " TC/ " bit in the TMOD Special Function Register.
Each Timer/Counter has one selection bit for its own; bit 2 of TMOD selects the function for Tim-
er/Counter 0 and bit 6 of TMOD selects the function for Timer/Counter 1. In addition each Tim-
er/Counter can be set to operate in any one of four possible modes. The mode selection is done by
bits M0 and M1 in the TMOD SFR.
14.2 Time-Base Selection
W78E054D/W78E052D/W78E051D provides users with two modes of operation for the timer. The
timers can be programmed to operate like the standard 8051 family, counting at the rate of 1/12 of the
clock speed. This will ensure that timing loops on W78E054D/W78E052D/W78E051D and the stan-
dard 8051 can be matched. This is the default mode of operation of the
W78E054D/W78E052D/W78E051D timers.
14.2.1 Mode 0
In Mode 0, the timer/counter is a 13-bit counter. The 13-bit counter consists of THx (8 MSB) and the
five lower bits of TLx (5 LSB). The upper three bits of TLx are ignored. The timer/counter is enabled
when TRx is set and either GATE is 0 or INTx is 1. When TC / is 0, the timer/counter counts clock
cycles; when TC / is 1, it counts falling edges on T0 (Timer 0) or T1 (Timer 1). For clock cycles, the
time base be 1/12 speed, and the falling edge of the clock increments the counter. When the 13-bit
value moves from 1FFFh to 0000h, the timer overflow flag TFx is set, and an interrupt occurs if en-
abled.
14.2.2 Mode 1
Mode 1 is similar to Mode 0 except that the counting register forms a 16-bit counter, rather than a 13-
bit counter. This means that all the bits of THx and TLx are used. Roll-over occurs when the timer
moves from a count of 0FFFFh to 0000h. The timer overflow flag TFx of the relevant timer is set and if
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 51 - Revision A10
enabled an interrupt will occur. The selection of the time-base in the timer mode is similar to that in
Mode 0. The gate function operates similarly to that in Mode 0.
1/12Fosc
T0=P3.4
(T1=P3.5)
0
1
TR0=TCON.4
(TR1=TCON.6)
GATE=TMOD.3
(GATE=TMOD.7)
INT0=P3.2
(INT1=P3.3)
C/T=TMOD.2
(C/T=TMOD.6)
0707
TFx Interrupt
TL0
(TL1)
TH0
(TH1)
TF0
(TF1)
4
M1, M0=TMOD.1, TMOD.0
(M1, M0=TMOD.5, TMOD.4)
00
01
Figure 14–1 Timer/Counters 0 & 1 in Mode 0, 1
14.2.3 Mode 2
In Mode 2, the timer/counter is in the Auto Reload Mode. In this mode, TLx acts as an 8-bit count reg-
ister, while THx holds the reload value. When the TLx register overflows from FFh to 00h, the TFx bit
in TCON is set and TLx is reloaded with the contents of THx, and the counting process continues from
here. The reload operation leaves the contents of the THx register unchanged. Counting is enabled by
the TRx bit and proper setting of GATE and INTx pins. As in the other two modes 0 and 1 mode 2
allows counting of clock/12 or pulses on pin Tn.
1/12Fosc
T0=P3.4
(T1=P3.5)
0
1
TR0=TCON.4
(TR1=TCON.6)
GATE=TMOD.3
(GATE=TMOD.7)
INT0=P3.2
(INT1=P3.3)
C/T=TMOD.2
(C/T=TMOD.6)
07
07
TFx Interrupt
TL0
(TL1)
TH0
(TH1)
TF0
(TF1)
Figure 14–2 Timer/Counter 0 & 1 in Mode 2
14.2.4 Mode 3
Mode 3 has different operating methods for the two timer/counters. For timer/counter 1, mode 3 simply
freezes the counter. Timer/Counter 0, however, configures TL0 and TH0 as two separate 8 bit count
registers in this mode. The logic for this mode is shown in the figure. TL0 uses the Timer/Counter 0
W78E054D/W78E052D/W78E051D Data Sheet
- 52 -
control bits TC/ , GATE, TR0, INT0 and TF0. The TL0 can be used to count clock cycles (clock/12) or
1-to-0 transitions on pin T0 as determined by C/T (TMOD.2). TH0 is forced as a clock cycle counter
(clock/12) and takes over the use of TR1 and TF1 from Timer/Counter 1. Mode 3 is used in cases
where an extra 8 bit timer is needed. With Timer 0 in Mode 3, Timer 1 can still be used in Modes 0, 1
and 2, but its flexibility is somewhat limited. While its basic functionality is maintained, it no longer has
control over its overflow flag TF1 and the enable bit TR1. Timer 1 can still be used as a timer/counter
and retains the use of GATE and INT1 pin. In this condition it can be turned on and off by switching it
out of and into its own Mode 3. It can also be used as a baud rate generator for the serial port.
Figure 14–3 Timer/Counter Mode 3
14.3 Timer/Counter 2
Timer/Counter 2 is a 16 bit up/down counter which is configured by the T2MOD(bit 0) register and
controlled by the T2CON register. Timer/Counter 2 is equipped with a capture/reload capability. As
with the Timer 0 and Timer 1 counters, there exists considerable flexibility in selecting and controlling
the clock, and in defining the operating mode. The clock source for Timer/Counter 2 may be selected
for either the external T2 pin (C/T2 = 1) or the crystal oscillator, which is divided by 12 (C/T2 = 0). The
clock is then enabled when TR2 is a 1, and disabled when TR2 is a 0.
14.3.1 Capture Mode
The capture mode is enabled by setting the CP RL/2
bit in the T2CON register to a 1. In the capture
mode, Timer/Counter 2 serves as a 16 bit up counter. When the counter rolls over from 0FFFFh to
0000h, the TF2 bit is set, which will generate an interrupt request. If the EXEN2 bit is set, then a nega-
tive transition of T2EX pin will cause the value in the TL2 and TH2 register to be captured by the
RCAP2L and RCAP2H registers. This action also causes the EXF2 bit in T2CON to be set, which will
also generate an interrupt.
(RCLK,TCLK, RL2CP / )= (0,0,1)
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 53 - Revision A10
Figure 14–4 16-Bit Capture Mode
14.3.2 Auto-Reload Mode, Counting up
The auto-reload mode as an up counter is enabled by clearing the CP RL/2
bit in the T2CON register
and clearing the DCEN bit in T2MOD(bit0) register. In this mode, Timer/Counter 2 is a 16 bit up coun-
ter. When the counter rolls over from 0FFFFh, a reload is generated that causes the contents of the
RCAP2L and RCAP2H registers to be reloaded into the TL2 and TH2 registers. The reload action also
sets the TF2 bit. If the EXEN2 bit is set, then a negative transition of T2EX pin will also cause a reload.
This action also sets the EXF2 bit in T2CON.
(RCLK,TCLK, RL2CP / )= (0,0,0) & DCEN= 0
T2=P1.0
0
1
C/T2=T2CON.1
Timer2
Interrupt
T2CON.6
TR2=T2CON.2
T2CON.7
Figure 14–5 16-Bit Auto-reload Mode, Counting Up
14.3.3 Auto-reload Mode, Counting Up/Down
Timer/Counter 2 will be in auto-reload mode as an up/down counter if CP RL/2 bit in T2CON is
cleared and the DCEN bit in T2MOD is set. In this mode, Timer/Counter 2 is an up/down counter
whose direction is controlled by the T2EX pin. A 1 on this pin cause the counter to count up. An over-
flow while counting up will cause the counter to be reloaded with the contents of the capture registers.
The next down count following the case where the contents of Timer/Counter equal the capture regis-
ters will load a 0FFFFh into Timer/Counter 2. In either event a reload will set the TF2 bit. A reload will
also toggle the EXF2 bit. However, the EXF2 bit cannot generate an interrupt while in this mode.
W78E054D/W78E052D/W78E051D Data Sheet
- 54 -
(RCLK,TCLK, RL2CP / )= (0,0,0) & DCEN= 1
T2=P1.0
0
1
T2EX=P1.1
C/T2=T2CON.1
Timer2
Interrupt
T2CON.6
TR2=T2CON.2
T2CON.7
Down Counting Reload Value
Up Counting Reload Value
Figure 14–6 16-Bit Auto-reload Mode, Counting Up
14.3.4 Baud Rate Generator Mode
The baud rate generator mode is enabled by setting either the RCLK or TCLK bits in T2CON register.
While in the baud rate generator mode, Timer/Counter 2 is a 16 bit counter with auto reload when the
count rolls over from 0FFFFh. However, rolling over does not set the TF2 bit. If EXEN2 bit is set, then
a negative transition of the T2EX pin will set EXF2 bit in the T2CON register and cause an interrupt
request.
RCLK+TCLK=1, RL2CP /=0
Figure 14–7 Baud Rate Generator Mode
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 55 - Revision A10
15 WATCHDOG TIMER
The Watchdog timer is a free-running timer which can be programmed by the user to serve as a sys-
tem monitor, a time-base generator or an event timer. It is basically a set of dividers that divide the
system clock. The divider output is selectable and determines the time-out interval. When the time-out
occurs a system reset can also be caused if it is enabled. The main use of the Watchdog timer is as a
system monitor. This is important in real-time control applications. In case of power glitches or electro-
magnetic interference, the processor may begin to execute errant code. If this is left unchecked the
entire system may crash. The watchdog time-out selection will result in different time-out values de-
pending on the clock speed. The Watchdog timer will de disabled on reset. In general, software should
restart the Watchdog timer to put it into a known state. The control bits that support the Watchdog tim-
er are discussed below.
ENW : Enable watchdog if set.
CLRW : Clear watchdog timer and Pre-scalar if set. This flag will be cleared automatically
WIDL : If this bit is set, watch-dog is enabled under IDLE mode. If cleared, watchdog is disabled un-
der IDLE mode. Default is cleared.
PS2, PS1, PS0: Watchdog Pre-scalar timer select. Pre-scalar is selected when set PS2−0 as follows:
PS2 PS1 PS0 Pre-scalar select
0 0 0 2
0 0 1 8
0 1 0 4
0 1 1 16
1 0 0 32
1 0 1 64
1 1 0 128
1 1 1 256
The time-out period is obtained using the following equation for 12T per machine cycle:
msscalare
OSC 121000Pr2
114 ××−××
Before Watchdog time-out occurs, the program must clear the 14-bit timer by writing 1 to WDTC.6
(CLRW). After 1 is written to this bit, the 14-bit timer, Pre-scalar and this bit will be reset on the next
instruction cycle. The Watchdog timer is cleared on reset.
W78E054D/W78E052D/W78E051D Data Sheet
- 56 -
Figure 15–1 Watchdog Timer Block Diagram
Typical Watch-Dog time-out period when OSC = 20 MHz
PS2 PS1 PS0 Watchdog time-out period
(for 12T per machine cycle)
0 0 0 19.66 mS
0 1 0 78.64 mS
0 0 1 39.32 mS
0 1 1 157.28 mS
1 0 0 314.57 mS
1 0 1 629.14 mS
1 1 0 1.25 S
1 1 1 2.50 S
Table 15–2 Watch-Dog time-out period for 12T per machine cycle, 20MHz
PS2 PS1 PS0 Watchdog time-out period
(for 6T per machine cycle)
0 0 0 9.83 mS
0 1 0 39.32 mS
0 0 1 19.66 mS
0 1 1 78.64 mS
1 0 0 157.28 mS
1 0 1 314.57mS
1 1 0 629.14 mS
1 1 1 1.250 S
Table 15–3 Watch-Dog time-out period for 6T per machine cycle, 20MHz
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 57 - Revision A10
16 SERIAL PORT
Serial port in this device is a full duplex port. The serial port is capable of synchronous as well as
asynchronous communication. In Synchronous mode the device generates the clock and operates in a
half-duplex mode. In the asynchronous mode, full duplex operation is available. This means that it can
simultaneously transmit and receive data. The transmit register and the receive buffer are both ad-
dressed as SBUF Special Function Register. However any write to SBUF will be to the transmit regis-
ter, while a read from SBUF will be from the receiver buffer register. The serial port can operate in four
different modes as described below.
16.1 MODE 0
This mode provides synchronous communication with external devices. In this mode serial data is
transmitted and received on the RXD line. TXD is used to transmit the shift clock. The TxD clock is
provided by the device whether it is transmitting or receiving. This mode is therefore a half-duplex
mode of serial communication. In this mode, 8 bits are transmitted or received per frame. The LSB is
transmitted/received first. The baud rate is fixed at 1/12 of the oscillator frequency. This Baud Rate is
determined by the SM2 bit (SCON.5). When this bit is set to 0, then the serial port runs at 1/12 of the
clock. This additional facility of programmable baud rate in mode 0 is the only difference between the
standard 8051 and W78E054D/W78E052D/W78E051D.
The functional block diagram is shown below. Data enters and leaves the Serial port on the RxD line.
The TxD line is used to output the shift clock. The shift clock is used to shift data into and out of this
device and the device at the other end of the line. Any instruction that causes a write to SBUF will start
the transmission. The shift clock will be activated and data will be shifted out on the RxD pin till all 8
bits are transmitted. If SM2 = 1, then the data on RxD will appear 1 clock period before the falling
edge of shift clock on TxD. The clock on TxD then remains low for 2 clock periods, and then goes high
again. If SM2 = 0, the data on RxD will appear 3 clock periods before the falling edge of shift clock on
TxD. The clock on TxD then remains low for 6 clock periods, and then goes high again. This ensures
that at the receiving end the data on RxD line can either be clocked on the rising edge of the shift
clock on TxD or latched when the TxD clock is low.
W78E054D/W78E052D/W78E051D Data Sheet
- 58 -
Figure 16–1 Serial port mode 0
The TI flag is set high in S6P2 following the end of transmission of the last bit. The serial port will re-
ceive data when REN is 1 and RI is zero. The shift clock (TxD) will be activated and the serial port will
latch data on the rising edge of shift clock. The external device should therefore present data on the
falling edge on the shift clock. This process continues till all the 8 bits have been received. The RI flag
is set in S6P2 following the last rising edge of the shift clock on TxD. This will stop reception, till the RI
is cleared by software.
16.2 MODE 1
In Mode 1, the full duplex asynchronous mode is used. Serial communication frames are made up of
10 bits transmitted on TXD and received on RXD. The 10 bits consist of a start bit (0), 8 data bits (LSB
first), and a stop bit (1). On receive, the stop bit goes into RB8 in the SFR SCON. The baud rate in this
mode is variable. The serial baud can be programmed to be 1/16 or 1/32 of the Timer 1 overflow.
Since the Timer 1 can be set to different reload values, a wide variation in baud rates is possible.
Transmission begins with a write to SBUF. The serial data is brought out on to TxD pin at S6P2 follow-
ing the first roll-over of divide by 16 counter. The next bit is placed on TxD pin at S6P2 following the
next rollover of the divide by 16 counter. Thus the transmission is synchronized to the divide by 16
counter and not directly to the write to SBUF signal. After all 8 bits of data are transmitted, the stop bit
is transmitted. The TI flag is set in the S6P2 state after the stop bit has been put out on TxD pin. This
will be at the 10th rollover of the divide by 16 counters after a write to SBUF.
Reception is enabled only if REN is high. The serial port actually starts the receiving of serial data,
with the detection of a falling edge on the RxD pin. The 1-to-0 detector continuously monitors the RxD
line, sampling it at the rate of 16 times the selected baud rate. When a falling edge is detected, the
divide by 16 counters is immediately reset. This helps to align the bit boundaries with the rollovers of
the divide by 16 counters.
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 59 - Revision A10
The 16 states of the counter effectively divide the bit time into 16 slices. The bit detection is done on a
best of three basis. The bit detector samples the RxD pin, at the 8th, 9th and 10th counter states. By
using a majority 2 of 3 voting system, the bit value is selected. This is done to improve the noise rejec-
tion feature of the serial port. If the first bit detected after the falling edge of RxD pin is not 0, then this
indicates an invalid start bit, and the reception is immediately aborted. The serial port again looks for a
falling edge in the RxD line. If a valid start bit is detected, then the rest of the bits are also detected
and shifted into the SBUF.
After shifting in 8 data bits, there is one more shift to do, after which the SBUF and RB8 are loaded
and RI is set. However certain conditions must be met before the loading and setting of RI can be
done.
1. RI must be 0 and
2. Either SM2 = 0, or the received stop bit = 1.
If these conditions are met, then the stop bit goes to RB8, the 8 data bits go into SBUF and RI is set.
Otherwise the received frame may be lost. After the middle of the stop bit, the receiver goes back to
looking for a 1-to-0 transition on the RxD pin.
1/2
1/16 TX CLOCK
RX CLOCK
TI
RI
TX SHIFT
TX START
RX SHIFT
LOAD SBUF
SMOD
CLOCK
SIN D8
SBUF
Read SBUF
Internal
Data Bus
Serial
Controllor
CLOCK
LOAD
PARIN
TX START
Internal
Data Bus
Write to
SBUF SOUT
Transmit Shift Register
Serial Interrupt
TXD
RXD
PAROUT
RB8
START
STOP
0
1
BIT
DETECTOR
1-To-0
DETECTOR
SAMPLE
1/16
0
Timer 1
Overflow
1
Receive Shift Register
01
01
TCLK
RCLK
Timer 2
Overflow
Figure 16–2 Serial port mode 1
16.3 MODE 2
This mode uses a total of 11 bits in asynchronous full-duplex communication. The functional descrip-
tion is shown in the figure below. The frame consists of one start bit (0), 8 data bits (LSB first), a pro-
grammable 9th bit (TB8) and a stop bit (1). The 9th bit received is put into RB8. The baud rate is pro-
W78E054D/W78E052D/W78E051D Data Sheet
- 60 -
grammable to 1/32 or 1/64 of the oscillator frequency, which is determined by the SMOD bit in PCON
SFR. Transmission begins with a write to SBUF. The serial data is brought out on to TxD pin at S6P2
following the first roll-over of the divide by 16 counter. The next bit is placed on TxD pin at S6P2 fol-
lowing the next rollover of the divide by 16 counter. Thus the transmission is synchronized to the di-
vide by 16 counters, and not directly to the write to SBUF signal. After all 9 bits of data are transmitted,
the stop bit is transmitted. The TI flag is set in the S6P2 state after the stop bit has been put out on
TxD pin. This will be at the 11th rollover of the divide by 16 counters after a write to SBUF. Reception
is enabled only if REN is high. The serial port actually starts the receiving of serial data, with the de-
tection of a falling edge on the RxD pin. The 1-to-0 detector continuously monitors the RxD line, sam-
pling it at the rate of 16 times the selected baud rate. When a falling edge is detected, the divide by 16
counters is immediately reset. This helps to align the bit boundaries with the rollovers of the divide by
16 counters. The 16 states of the counter effectively divide the bit time into 16 slices. The bit detection
is done on a best of three basis. The bit detector samples the RxD pin, at the 8th, 9th and 10th coun-
ter states. By using a majority 2 of 3 voting system, the bit value is selected. This is done to improve
the noise rejection feature of the serial port.
1/2
1/16 TX CLOCK
RX CLOCK
TI
RI
TX SHIFT
TX START
RX SHIFT
LOAD SBUF
SMOD
CLOCK
SIN D8
SBUF
Read SBUF
Internal
Data Bus
Serial
Controllor
CLOCK
LOAD
PARIN
TX START
Internal
Data Bus
Write to
SBUF SOUT
Transmit Shift Register
Serial Interrupt
TXD
RXD
PAROUT
RB8
START
STOP
0
1
BIT
DETECTOR
1-To-0
DETECTOR
SAMPLE
1/16
0
Fosc/2
1
D8
TB8
Receive Shift Register
Figure 16–3 Serial port mode 2
If the first bit detected after the falling edge of RxD pin, is not 0, then this indicates an invalid start bit,
and the reception is immediately aborted. The serial port again looks for a falling edge in the RxD line.
If a valid start bit is detected, then the rest of the bits are also detected and shifted into the SBUF. Af-
ter shifting in 9 data bits, there is one more shift to do, after which the SBUF and RB8 are loaded and
RI is set. However certain conditions must be met before the loading and setting of RI can be done.
1. RI must be 0 and
2. Either SM2 = 0, or the received stop bit = 1.
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 61 - Revision A10
If these conditions are met, then the stop bit goes to RB8, the 8 data bits go into SBUF and RI is set.
Otherwise the received frame may be lost. After the middle of the stop bit, the receiver goes back to
looking for a 1-to-0 transition on the RxD pin.
MODE 3
This mode is similar to Mode 2 in all respects, except that the baud rate is programmable. The user
must first initialize the Serial related SFR SCON before any communication can take place. This in-
volves selection of the Mode and baud rate. The Timer 1 should also be initialized if modes 1 and 3
are used. In all four modes, transmission is started by any instruction that uses SBUF as a destination
register. Reception is initiated in Mode 0 by the condition RI = 0 and REN = 1. This will generate a
clock on the TxD pin and shift in 8 bits on the RxD pin. Reception is initiated in the other modes by the
incoming start bit if REN = 1. The external device will start the communication by transmitting the start
bit.
Figure 16–4 Serial port mode 3
SM0 SM1 Mode Type Baud Clock Frame
Size
Start
Bit
Stop
Bit
9th bit
Function
0 0 0 Synch. 4 or 12 TCLKS 8 bits No No None
0 1 1 Asynch. Timer 1 or 2 10 bits 1 1 None
1 0 2 Asynch. 32 or 64
TCLKS
11 bits 1 1 0, 1
1 1 3 Asynch. Timer 1 or 2 11 bits 1 1 0, 1
Table 16–5 Serial Ports Modes
W78E054D/W78E052D/W78E051D Data Sheet
- 62 -
17 FLASH ROM CODE BOOT MODE SLECTION
The W78E054D/W78E052D/W78E051D boots from APROM program (16K/8K/4K bytes) or LDROM
program (2K bytes) at power on reset or external reset.
BOOT MODE Select by CONFIG bits
CBS (CONFIG.2) Config boot select at Power-on reset and external reset.
1: Boot from APROM (0x0000).
0: Boot from LDROM (0x3800).
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 63 - Revision A10
18 ISP (IN-SYSTEM PROGRAMMING)
ISP is the ability of program MCU to be programmed while F/W code in AP-ROM or LD-ROM. (Note:
Timer 0 for program, erase, read on ISP mode. ISP operation voltage 3.3- 5.5V)
START
Setting control registers
MOV SFRCN,#3Fh
MOV SFRFD,#ABh
MOV SFRAL,#FFh
MOV SFRAH,#FFh
MOV CHPCON,#03h
Setting Timer (about 450 us)
and enable timer interrupt
Start Timer and enter idle Mode.
(CPU will be wakened from idle mode
by timer interrupt, then enter In-System
Programming mode)
Part 1:2KB APROM
procedure of entering
In-System Programming Mode
Execute the normal
Application program
Enter In-System
Programming Mode ?
(conditions depend on
user's application)
END
YES
GO
NO
W78E054D/W78E052D/W78E051D Data Sheet
- 64 -
GO
Timer Interrupt Service Routine:
Stop Timer & disable interrupt
End of Programming
End of erase
operation. CPU will
be wakened by Timer
interrupt.
Setting Timer and enable Timer
interrupt for wake-up .
(15 ms for erasing operation)
Start Timer and enter IDLE
Mode.
(Erasing...)
Part 2:
Procedure of Updating
the 2KB APROM
Is F02K BOOT Mode?
Setting erase operation mode:
MOV ERPAGE,#02H
MOV SFRCN,#22H
(Erase 2KB APROM ISP )
PGM
NO
YES
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 65 - Revision A10
PGM
Read_Device_ID
MOV SFRCN,#0Ch
MOV CHPCON,#03h
Setting Timer and enable Timer
interrupt for wake-up .
(50us for program operation)
Read_VT
MOV SFRCN,#0Dh
MOV SFRAL,#01h
MOV SFRAH,#00h
MOV CHPCON,#03h
.
Part 2:
Procedure of Updating
the 2KB APROM
End of Programming ?
Get the parameters of new code
(Address and data bytes)
through I/O ports, UART or
other interfaces
.
Setting control registers for
programming:
MOV SFRAH,#ADDRESS_H
MOV SFRAL,#ADDRESS_L
MOV SFRFD,#DATA
MOV SFRCN,#21H
NO
YES
Read_Compay_ID
OV SFRCN,#0Bh
MOV CHPCON,#03h
Read_Dist
MOV SFRCN,#0Eh
MOV SFRAL,#02h
MOV SFRAH,#00h
MOV CHPCON,#03h
.
Is currently in the
F02K BOOT Mode ?
Ease 14K AP programming:
MOV ERPAGE,#01
MOV SFRCN,#22H
W78E054D/W78E052D/W78E051D Data Sheet
- 66 -
PGM
Software reset CPU and
re-boot from the 2KB
APROM.
MOV CHPCON,#81h
Hardware Reset
to re-boot from
new 2 KB APROM.
(S/W reset is
invalid in F02K BOOT
Mode)
Setting Timer and enable Timer
interrupt for wake-up .
(50us for program operation)
END
Executing new code
from address
00H in the 2KB APROM.
Part 2:
Procedure of Updating
the 2KB APROM
End of Programming ?
Get the parameters of new code
(Address and data bytes)
through I/O ports, UART or
other interfaces.
Setting control registers for
programming:
MOV SFRAH,#ADDRESS_H
MOV SFRAL,#ADDRESS_L
MOV SFRFD,#DATA
MOV SFRCN,#21H
Is currently in the
F02K BOOT Mode ?
NO
YES
NO
YES
Read_Compay_ID
Read_Device_ID
Read_VT
Read_Dist
Ease 14K AP programming:
MOV ERPAGE,#01
MOV SFRCN,#22H
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 67 - Revision A10
19 CONFIG BITS
During the on-chip Flash EPROM operation mode, the Flash EPROM can be programmed and veri-
fied repeatedly. Until the code inside the Flash EPROM is confirmed OK, the code can be protected.
The protection of Flash EPROM and those operations on it are described below.
The W78E054D/W78E052D/W78E051D has a Special Setting Register, the config Bits, which cannot
be accessed in normal mode. The Security register can only be accessed from the Flash EPROM op-
eration mode. Those bits of the Security Registers cannot be changed once they have been pro-
grammed from high to low. They can only be reset through erase-all operation. The Security Register
is addressed in the Flash EPROM operation mode by address #0FFFFh.
W78E054D/W78E052D/W78E051D Data Sheet
- 68 -
Bit 0: Lock bits
0: Lock enable
1: Lock disable
This bit is used to protect the customer's program code in the W78E054D/W78E052D/W78E051D. It
may be set after the programmer finishes the programming and verifies sequence. Once these bits are
set to logic 0, both the FLASH data and Special Setting Registers cannot be accessed again.
Bit 1: MOVC inhibit
0: MOVC inhibit enable
1: MOVC inhibit disable
This bit is used to restrict the accessible region of the MOVC instruction. It can prevent the MOVC in-
struction in external program memory from reading the internal program code. When this bit is set to
logic 0, a MOVC instruction in external program memory space will be able to access code only in the
external memory, not in the internal memory. A MOVC instruction in internal program memory space
will always be able to access the ROM data in both internal and external memory. If this bit is logic 1,
there are no restrictions on the MOVC instruction.
Bit 2: CBS
Config boot select at Power-on reset and external reset.
CBS=1: Boot from APROM block (default).
CBS=0: Boot from LDROM block (0x3800).
Bit 3: NSR (Noise Sensitivity Reduction)
NSR=1: Noise Sensitivity Reduction is disabled.
NSR=0: Noise Sensitivity Reduction is enabled.
Bit 4: Must be “1”
Bit 5: Machine Cy cle Select
This bit is select MCU core, default value is logic 1, and the MCU core is 12T per instruction. Once this
bit is set to logic 0, the MCU core is 6T per instruction.
Bit 6: Must be “1”
Bit 7: Crystal Select
0 (24MHz): If system clock is slower than 24MHz, programming “0”. It can reduce EMI effect and save
the power consumption.
1 (40MHz): If system clock is faster than 24MHz, programming “1”.
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 69 - Revision A10
20 ELECTRICAL CHARACTERISTICS
20.1 Absolute Maximum Ratings
SYMBOL PARAMETER Min MAX UNIT
DC Power Supply VDD−VSS 2.4 5.5 V
Input Voltage VIN V
SS-0.3 VDD+0.3 V
Operating Temperature
(W78E054D/W78E052D/W78
E051D)
TA -40 +85
°C
Note: Exposure to conditions beyond those listed under absolute maximum ratings may adversely af-
fects the lift and reliability of the device.
W78E054D/W78E052D/W78E051D Data Sheet
- 70 -
20.2 DC ELECT RICAL CHARACTERISTICS
TA =-40℃~+85℃, VDD=2.4V~5.5V, VSS=0V
Sym Parameter Test Condition Min
Typ*1 Max Unit
VIL Input Low Voltage
(Ports 0~4, /EA, XTAL1,
RST)
2.4 < VDD < 5.5V -0.5 0.2VDD
-0.1 V
VIH Input High Voltage
(Ports 0~4, /EA) 2.4 < VDD < 5.5V 0.2VDD
+0.9 VDD+
0.5 V
VIH1 Input High Voltage
(XTAL1, RST) 2.4 < VDD < 5.5V 0.7VDD VDD+
0.5 V
VOL Output Low Voltage
(Ports 0~4, ALE,
/PSEN)
VDD=4.5V, IOL= 12.0mA*3,*4
VDD=2.4V, IOL= 10mA*3,*4 0.4 V
VOH1 Output High Voltage
(Ports 1~4)
VDD=4.5V, IOH= -300μA*4
VDD=2.4V, IOH= -35μA*4
2.4
2.0 V
VOH2 Output High Voltage
(Ports 0 & 2 in external
bus mode, ALE, /PSEN)
VDD=4.5V, IOH= -8.0mA*4
VDD=2.4V, IOH= -2.2mA*4
2.4
2.0 V
I IL Logical 0 Input Current
(Ports 1~4) VDD=5.5V, VIN=0.4V -45 -50
μA
ITL Logical 1-to-0 Transition
Current (Ports 1~4) *2 VDD=5.5V, VIN=2.0V -510 -650
μA
I LI Input Leakage Current
(Port 0) 0 < VIN < VDD+0.5
±0.1 ±10 μA
Active mode*5
@12MHz, VDD=5.0V
@40MHz, VDD=5.0V
@12MHz, VDD=3.3V
@20MHz, VDD=3.3V
9.5
16.0
3.1
3.7
mA
Idle mode
@12MHz, VDD=5.0V
@40MHz, VDD=5.0V
@12MHz, VDD=3.3V
@20MHz, VDD=3.3V
3.5
9.2
1.2
1.7
mA
I DD Power Supply Current
Power-down mode <1 50 μA
RRST RST-pin Internal Pull-
down Resistor 2.4 < VDD < 5.5V 100 225 KΩ
Note:
*1: Typical values are not guaranteed. The values listed are tested at room temperature and based on
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 71 - Revision A10
a limited number of samples.
*2: Pins of ports 1~4 source a transition current when they are being externally driven from 1 to 0.
The transition current reaches its maximum value when VIN is approximately 2V.
*3: Under steady state (non-transient) conditions, IOL must be externally limited as follows:
Maximum IOL per port pin: 20mA
Maximum IOL per 8-bit port: 40mA
Maximum total IOL for all outputs: 100mA
*4: If IOH exceeds the test condition, VOH will be lower than the listed specification.
If IOL exceeds the test condition, VOL will be higher than the listed specification.
*5: Tested while CPU is kept in reset state and EA=H, Port0=H.
Voltage Max. Frequency 6T/12T mode Note
4.5-5.5V 40MHz 12T
4.5-5.5V 20MHz 6T
2.4V 20MHz 12T
2.4V 10MHz 6T
Frequency VS Voltage Table
20.3 AC ELECT RICAL CHARACTERISTICS
The AC specifications are a function of the particular process used to manufacture the part, the ratings
of the I/O buffers, the capacitive load, and the internal routing capacitance. Most of the specifications
can be expressed in terms of multiple input clock periods (TCP), and actual parts will usually experi-
ence less than a ±20 nS variation.
20.3.1 Clock Input Waveform
T
T
XTAL1
F
CH CL
OP, TCP
PARAMETER SYMBOL MIN. TYP. MAX. UNIT NOTES
Operating Speed Fop 0 - 40 MHz 1
Clock Period TCP 25 - - nS 2
Clock High Tch 10 - - nS 3
Clock Low Tcl 10 - - nS 3
Notes:
1. The clock may be stopped indefinitely in either state.
2. The TCP specification is used as a reference in other specifications.
W78E054D/W78E052D/W78E051D Data Sheet
- 72 -
3. There are no duty cycle requirements on the XTAL1 input.
20.3.2 Program Fetch Cycle
PARAMETER SYMBOL MIN. TYP. MAX. UNIT NOTES
Address Valid to ALE Low Taas 1 TCP -
Δ
- - nS 4
Address Hold from ALE Low Taah 1 TCP -
Δ
- - nS 1, 4
ALE Low to PSEN Low Tapl 1 TCP -
Δ
- - nS 4
PSEN Low to Data Valid Tpda - - 2 TCP nS 2
Data Hold after PSEN High Tpdh 0 - 1 TCP nS 3
Data Float after PSEN High Tpdz 0 - 1 TCP nS
ALE Pulse Width Talw 2 TCP -
Δ
2 TCP - nS 4
PSEN Pulse Width Tpsw 3 TCP -
Δ
3 TCP - nS 4
Notes:
1. P0.0−P0.7, P2.0−P2.7 remains stable throughout entire memory cycle.
2. Memory access time is 3 TCP.
3. Data have been latched internally prior to PSEN going high.
4. "Δ" (due to buffer driving delay and wire loading) is 20 nS.
20.3.3 Data Read Cycle
PARAMETER SYMBOL MIN. TYP. MAX. UNIT NOTES
ALE Low to RD Low Tdar 3 TCP -Δ- 3 TCP +Δ nS 1, 2
RD Low to Data Valid Tdda - - 4 TCP nS 1
Data Hold from RD High Tddh 0 - 2 TCP nS
Data Float from RD High Tddz 0 - 2 TCP nS
RD Pulse Width Tdrd 6 TCP -Δ6 TCP - nS 2
Notes:
1. Data memory access time is 8 TCP.
2. "Δ" (due to buffer driving delay and wire loading) is 20 nS.
20.3.4 Data Write Cycle
PARAMETER SYMBOL MIN. TYP. MAX. UNIT
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 73 - Revision A10
ALE Low to WR Low Tdaw 3 TCP -Δ- 3 TCP +Δ nS
Data Valid to WR Low Tdad 1 TCP -Δ- - nS
Data Hold from WR High Tdwd 1 TCP -Δ- - nS
WR Pulse Width Tdwr 6 TCP -Δ6 TCP - nS
Note: "Δ" (due to buffer driving delay and wire loading) is 20 nS.
20.3.5 Port Access Cycle
PARAMETER SYMBOL MIN. TYP. MAX. UNIT
Port Input Setup to ALE Low Tpds 1 TCP - - nS
Port Input Hold from ALE Low Tpdh 0 - - nS
Port Output to ALE Tpda 1 TCP - - nS
Note: Ports are read during S5P2, and output data becomes available at the end of S6P2. The timing
data are referenced to ALE, since it provides a convenient reference.
20.3.6 Program Operation
PARAMETER Symbol Min. TYP. Max. Unit
VPP Setup Time TVPS 2.0 - - μS
Data Setup Time TDS 2.0 - - μS
Data Hold Time TDH 2.0 - - μS
Address Setup Time TAS 2.0 - - μS
Address Hold Time TAH 0 - - μS
CE Program Pulse Width for Pro-
gram Operation
TPWP 290 300 310
μS
OECTRL Setup Time TOCS 2.0 - - μS
OECTRL Hold Time TOCH 2.0 - - μS
OE Setup Time TOES 2.0 - - μS
OE High to Output Float TDFP 0 - 130 nS
Data Valid from OE TOEV - - 150 nS
Note: Flash data can be accessed only in flash mode. The RST pin must pull in VIH status, the ALE
pin must pull in VIL status, and the PSEN pin must pull in VIH status.
W78E054D/W78E052D/W78E051D Data Sheet
- 74 -
20.4 TIMING waveforms
20.4.1 Program Fetch Cycle
S1
XTAL1
S2 S3 S4 S5 S6 S1 S2 S3 S4 S5 S6
ALE
PORT 2
A0-A7
A0-A7 Data
A0-A7 Code
T
A0-A7 Data
Code
PORT 0
PSEN
PDH, TPDZ
TPDA
TAAH
TAAS
TPSW
TAPL
TALW
20.4.2 Data Read Cycle
S2 S3S5 S6 S1S2 S3 S4S1S5 S6S4
XTAL1
ALE
PSEN
A8-A15
DATA OUT
PORT 2
PORT 0 A0-A7
WR T
TDAW
DAD
TDWR
TDWD
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 75 - Revision A10
20.4.3 Data Write Cycle
S2 S3S5 S6 S1S2 S3 S4S1S5 S6S4
XTAL1
ALE
PSEN
A8-A15
DATA OUT
PORT 2
PORT 0 A0-A7
WR T
TDAW
DAD
TDWR
TDWD
20.4.4 Port Access Cycle
XTAL1
ALE
S5 S6 S1
DATA OUT
T
T
PORT
INPUT
T
SAMPLE
PDA
PDHPDS
W78E054D/W78E052D/W78E051D Data Sheet
- 76 -
20.4.5 Reset Pin Access Cycle
VSS
VDD
POF
Internal
Reset
Power
1 = reset state
0 = cpu free running
~0.7V
Reset
Pin
ALE
Crystal
Clock
65536 crystal clock
~2.0V
12 Crystal Clock = 1 Machine Cycle
24 crystal clock
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 77 - Revision A10
21 APPLICATION CIRCUITS
21.1 External Program Memory and Crystal
A9
A11
PSEN
A1
VCC
AD2
RST A8
R
A3
A13A12
C2
64KB ROM
10
9
8
7
6
5
4
3
25
24
21
23
2
26
27
1
20
22
11
12
13
15
16
17
18
19
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10
A11
A12
A13
A14
A15
CE
OE
O0
O1
O2
O3
O4
O5
O6
O7
AD5
AD5
AD4
C1
AD7
AD3
A10
AD1
74373
3 2
4 5
7 6
8 9
13 12
14 15
17 16
18 19
1
11
D0 Q0
D1 Q1
D2 Q2
D3 Q3
D4 Q4
D5 Q5
D6 Q6
D7 Q7
OC
G
AD2
A15
A14
AD1
A7
ALE
A4
CRYSTAL
A11
VCC
AD5
A6
A2
A0
AD6
AD4
A12
W78E054DDG-40DIP
31
19
18
9
12
13
14
15
1
2
3
4
5
6
7
8
39
38
37
36
35
34
33
32
21
22
23
24
25
26
27
28
17
16
29
30
11
10
20
40
EA
XTAL1
XTAL2
RST
P3.2/INT0
P3.3/INT1
P3.4/T0
P3.5/T1
P1.0/T2
P1.1/T2EX
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
P0.0
P0.1
P0.2
P0.3
P0.4
P0.5
P0.6
P0.7
P2.0
P2.1
P2.2
P2.3
P2.4
P2.5
P2.6
P2.7
RD/P3.7
WR/P3.6
PSEN
ALE
TXD/P3. 1
RXD/P3.0
VSS
VDD
A8
A5
A1
A6
W78E052DDG-40DIP
W78E051DDG-40DIP
A4
10uF
A0
AD7
A2 AD2
AD3
A15
A14
A3
A10
AD7
A9
AD6
AD1
AD0
A5
A13
AD4
AD6
AD3
AD0
8.2K
A7
AD0
Figure A
21.2 Expanded External Data Memory and Oscillator
64KB RAM
12
11
10
9
8
7
6
5
27
26
23
25
4
28
3
31
13
14
15
17
18
19
20
21
22
30
24
29
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10
A11
A12
A13
A14
A15
D0
D1
D2
D3
D4
D5
D6
D7
CS1
CS2
OE
WE
AD7
A13
A10
AD4
A12
A7
8.2K
A15
A13
AD2
A5
A6
10uF
A1
AD5
A8
A3
A2
ALE
AD6
AD1
A12
A15
A4
A8
A5
VCC
RST
AD0
A10
AD1
A4
AD1
AD6
/WR
VCC
AD7
A14
AD6
74373
3 2
4 5
7 6
8 9
13 12
14 15
17 16
18 19
1
11
D0 Q0
D1 Q1
D2 Q2
D3 Q3
D4 Q4
D5 Q5
D6 Q6
D7 Q7
OC
G
W78E052DDG-40DIP
W78E051DDG-40DIP
A14
VCC
AD5
A6
AD2
AD4
A7
A2
AD4
/RD
AD5
A9
AD7
AD3
A0
A11
A9
A1
Oscillator
A0
AD3
VCC
AD0
A11
AD3
AD2
A3
AD0
W78E054DDG-40DIP
31
19
18
9
12
13
14
15
1
2
3
4
5
6
7
8
39
38
37
36
35
34
33
32
21
22
23
24
25
26
27
28
17
16
29
30
11
10
20
40
EA
XTA L 1
XTA L 2
RST
P3.2/INT0
P3.3/INT1
P3.4/T0
P3.5/T1
P1.0/T2
P1.1/T2EX
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
P0.0
P0.1
P0.2
P0.3
P0.4
P0.5
P0.6
P0.7
P2.0
P2.1
P2.2
P2.3
P2.4
P2.5
P2.6
P2.7
RD/P3.7
WR/P3.6
PSEN
ALE
TXD/ P3 . 1
RXD/P3.0
VSS
VDD
Figure B
W78E054D/W78E052D/W78E051D Data Sheet
- 78 -
21.3 Internal Program Memory and Oscillator for EFT application
AD6
AD4
A12
AD5
8.2K
AD4
10uF
AD7
A3
AD1
VCC
A9
AD5
AD0
A6
AD2
A15
A15
A0A0
A6
A12
AD3
A10
RST
A1
A9
A5
AD2
A11
AD3
W78E054DDG-40DIP
EA
31
XTAL1
19
XTAL2
18
RST
9
P3.2/INT0
12
P3.3/INT1
13
P3.4/T0
14
P3.5/T1
15
P1.0/T2
1
P1.1/T2EX
2
P1.2
3
P1.3
4
P1.4
5
P1.5
6
P1.6
7
P1.7
8
P0.0 39
P0.1 38
P0.2 37
P0.3 36
P0.4 35
P0.5 34
P0.6 33
P0.7 32
P2.0 21
P2.1 22
P2.2 23
P2.3 24
P2.4 25
P2.5 26
P2.6 27
P2.7 28
RD/P3.7 17
WR/P3.6 16
PSEN 29
ALE 30
TXD/ P3. 1 11
RXD/P3.0 10
VSS 20
VDD 40
A4
AD5
AD0
AD3
AD1
A13
AD7
A1
A8
AD7
ALE
A11
AD1
AD6
A2
A10
74373
D0
3Q0 2
D1
4Q1 5
D2
7Q2 6
D3
8Q3 9
D4
13 Q4 12
D5
14 Q5 15
D6
17 Q6 16
D7
18 Q7 19
OC
1
G
11
AD4
A14
AD0
A14
A5
A13
A3
A7 A7
A8
AD6
VCC
A2AD2
A4
64KB RAM
A0
12
A1
11
A2
10
A3
9
A4
8
A5
7
A6
6
A7
5
A8
27
A9
26
A10
23
A11
25
A12
4
A13
28
A14
3
A15
31
D0 13
D1 14
D2 15
D3 17
D4 18
D5 19
D6 20
D7 21
CS1 22
CS2 30
OE 24
WE 29
/WR
/RD
VCC
W78E052DDG-40DIP
W78E051DDG-40DIP
CRY STAL
R
C2
C1
10K
Figure C
21.4 Reference Value of XTAL
CRYSTAL C1 C2 R
6 MHz 68P 68P -
16 MHz 47P 47P -
24 MHz 20P 20P -
32 MHz 10P 10P 6.8K
40 MHz 5P 5P 4.7K
Above table shows the reference values for crystal applications.
Notes:
1. C1, C2, R components refer to Figure A,C
2. Crystal layout must get close to XTAL1 and XTAL2 pins on user's application board.
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 79 - Revision A10
22 APPLICATION NOTE
In-system Programming Software Examples
This application note illustrates the in-system programmability of the microcontroller. In this example,
microcontroller will boot from 2K LDROM bank enter in-system programming mode for programming
the contents of APROM, this sample to Erase APROM, Erase Verify APROM, Read one byte for
APROM, Write one byte for APROM, Read CID/DID. .
EXAMPLE: Base on Keil C51 Compiler
$nomod51
#include <reg52.h>
EAPAGE DATA 0BEh
CHPCON DATA 0BFh
SFRAL DATA 0C4h
SFRAH DATA 0C5h
SFRFD DATA 0C6h
SFRCN DATA 0C7h
;CPU Clock = 12MHz/12T mode
READ_TIME EQU 1
PROGRAM_TIME EQU 50
ERASE_TIME EQU 5000
;For W78E(I)054D
APROM_END_ADDRESS EQU 03800h
;For W78E(I)052D
;APROM_END_ADDRESS EQU 02000h
;For W78E(I)051D
;APROM_END_ADDRESS EQU 01000h
FLASH_STANDBY EQU 00111111B
READ_CID EQU 00001011B
READ_DID EQU 00001100B
ERASE_ROM EQU 00100010B
ERASE_VERIFY EQU 00001001B
PROGRAM_ROM EQU 00100001B
PROGRAM_VERIFY_ROM EQU 00001010B
READ_ROM EQU 00000000B
ORG 03800h
mov SP,#060h
W78E054D/W78E052D/W78E051D Data Sheet
- 80 -
mov TMOD,#01h ;Set Timer0 as mode1
call Read_Company_ID
call Read_Device_ID_HIGH
call Read_Device_ID_LOW
call Erase_APROM
call Erase_Verify_ROM
call Program_APROM
call Program_Verify_APROM
call Software_Reset
sjmp $
;************************************************************************
; * Read_Company_ID
;************************************************************************
Read_Company_ID:
mov SFRCN,#READ_CID
mov TL0,#LOW (65536-READ_TIME)
mov TH0,#HIGH(65536-READ_TIME)
setb TR0
mov CHPCON,#00000011b
clr TF0
clr TR0
mov A,SFRFD ;check Read company ID
cjne A,#0DAh,CID_Error
ret
CID_Error:
mov P1,#01h
sjmp $
;************************************************************************
; * read device ID high
;************************************************************************
Read_Device_ID_HIGH:
mov SFRAL,#0FFh
mov SFRAH,#0FFh
mov SFRCN,#READ_DID
mov TL0,#LOW (65536-READ_TIME)
mov TH0,#HIGH(65536-READ_TIME)
setb TR0
mov CHPCON,#00000011b
clr TF0
clr TR0
mov A,SFRFD ;read device id high byte
ret
;*************************************************************************
; * read device ID low
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 81 - Revision A10
;*************************************************************************
Read_Device_ID_LOW:
mov SFRAL,#0FEh
mov SFRAH,#0FFh
mov SFRCN,#READ_DID
mov TL0,#LOW (65536-READ_TIME)
mov TH0,#HIGH(65536-READ_TIME)
setb TR0
mov CHPCON,#00000011b
clr TF0
clr TR0
mov A,SFRFD ;read device id low byte
ret
;************************************************************************
;* Flash standby mode
;************************************************************************
Standby:
mov SFRCN,#FLASH_STANDBY
mov SFRFD,#0FFh
mov SFRAL,#0FFh
mov SFRAH,#0FFh
setb TR0
mov CHPCON,#00000011b
clr TF0
clr TR0
ret
;************************************************************************
;* Erase APROM
;************************************************************************
Erase_APROM:
mov EAPAGE,#01h ;set EAPAGE is APROM
mov SFRCN,#ERASE_ROM
mov TL0,#LOW (65536-ERASE_TIME)
mov TH0,#HIGH(65536-ERASE_TIME)
setb TR0
mov CHPCON,#00000011b
mov EAPAGE,#00h ;clear EAPAGE
clr TF0
clr TR0
ret
;************************************************************************
; * VERIFY APROM BANK
;************************************************************************
W78E054D/W78E052D/W78E051D Data Sheet
- 82 -
Erase_Verify_ROM:
mov SFRCN,#ERASE_VERIFY
mov DPTR,#0000h
er_lp:
mov TL0,#LOW (65536-READ_TIME)
mov TH0,#HIGH(65536-READ_TIME)
mov SFRAL,DPL
mov SFRAH,DPH
setb TR0
mov CHPCON,#00000011b
clr TF0
clr TR0
mov A,SFRFD
cjne A,#0FFh,Erase_Verify_Error
inc DPTR
mov R0,DPL
cjne R0,#LOW (APROM_END_ADDRESS),er_lp
mov R1,DPH
cjne R1,#HIGH(APROM_END_ADDRESS),er_lp
ret
Erase_Verify_Error:
mov P1,#02h
sjmp $
;**************************************************************************
;*PROGRAMMING APROM BANK, APROM write 55h,AAh,55h,AAh........
;**************************************************************************
Program_APROM:
mov SFRCN,#PROGRAM_ROM
mov DPTR,#0000h
mov A,#055h
wr_lp:
mov TH0,#HIGH(65536-PROGRAM_TIME)
mov TL0,#LOW (65536-PROGRAM_TIME)
mov SFRFD,A
mov SFRAL,DPL
mov SFRAH,DPH
setb TR0
mov CHPCON,#00000011b
clr TF0
clr TR0
cpl A
inc DPTR
mov R0,DPL
cjne R0,#LOW (APROM_END_ADDRESS),wr_lp
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 83 - Revision A10
mov R1,DPH
cjne R1,#HIGH(APROM_END_ADDRESS),wr_lp
ret
;**************************************************************************
;*Program Verify APROM BANK, read APROM 55h,AAh,55h,AAh........
;**************************************************************************
Program_Verify_APROM:
mov SFRCN,#PROGRAM_VERIFY_ROM
mov DPTR,#0000h
mov B,#055h
rd_lp:
mov TH0,#HIGH(65536-READ_TIME)
mov TL0,#LOW (65536-READ_TIME)
mov SFRAL,DPL
mov SFRAH,DPH
setb TR0
mov CHPCON,#00000011b
clr TF0
clr TR0
mov A,SFRFD
cjne A,B,Program_Fail
mov A,B
cpl A
mov B,A
inc DPTR
mov R0,DPL
cjne R0,#LOW (APROM_END_ADDRESS),rd_lp
mov R1,DPH
cjne R1,#HIGH(APROM_END_ADDRESS),rd_lp
ret
Program_Fail:
mov P1,#03h
sjmp $
;**************************************************************************
;* PROGRAMMING COMPLETLY, SOFTWARE RESET CPU TO APROM
;**************************************************************************
Software_Reset:
MOV CHPCON,#081h ;CHPCON=081h, SOFTWARE RESET to APROM.
sjmp $
end
W78E054D/W78E052D/W78E051D Data Sheet
- 84 -
23 PACKAGE DIMENSIONS
23.1 40-pin DIP
1.371.22
0.0540.048
SymbolMin Nom Max Max
Nom
Min
Dimension in inch Dimension in mm
A
B
c
D
e
A
L
S
A
A1
2
E
0.050 1.27
0.210 5.33
0.010
0.150
0.016
0.155
0.018
0.160
0.022
3.81
0.41
0.25
3.94
0.46
4.06
0.56
0.008
0.120
0.670
0.010
0.130
0.014
0.140
0.20
3.05
0.25
3.30
0.36
3.56
0.540 0.550
0.545 13.72 13.97
13.84
17.02
15.24
14.99 15.49
0.6000.590 0.610
2.29 2.54 2.790.090 0.100 0.110
B1
1
e
E1
2.055 2.070 52.20 52.58
015
0.090 2.29
0.650
0.630 16.00 16.51
150
Seating Plane
eA
2
Ac
E
Base Plane
1
A
1
e
L
A
S
1
E
D
1
B
B
40 21
20
1
α
α
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 85 - Revision A10
23.2 44-pin PLCC
44 40
39
29
2818
17
7
61
L
c
1
b
2
A
H
D
D
eb
EH
E
y
A
A
1
Seating Plane
D
G
G
E
Symbol Min Nom Max Max
Nom
Min
Dimension in inch Dimension in mm
A
b
c
D
e
HE
L
y
A
A1
2
E
b1
HD
G
GD
E
0.020
0.145
0.026
0.016
0.008
0.648
0.590
0.680
0.090
0.150
0.028
0.018
0.010
0.653
0.610
0.690
0.100
0.050 BSC
0.185
0.155
0.032
0.022
0.014
0.658
0.630
0.700
0.110
0.004
0.51
3.68
0.66
0.41
0.20
16.46
14.99
17.27
2.29
3.81
0.71
0.46
0.25
16.59
15.49
17.53
2.54
1.27
4.70
3.94
0.81
0.56
0.36
16.71
16.00
17.78
2.79
0.10
BSC
16.71
16.59
16.46
0.658
0.653
0.648
16.00
15.4914.99
0.6300.610
0.590
17.7817.53
17.27
0.700
0.690
0.680
W78E054D/W78E052D/W78E051D Data Sheet
- 86 -
23.3 44-pin PQFP
0.250.10
0.0100.004
Symbol Min Nom Max Max
Nom
Min
Dimension in inch Dimension in mm
A
b
c
D
e
HD
HE
L
y
0
A
A
L1
1
2
E
0.006 0.15
- -
0.002
0.075
0.01
0.081
0.014
0.087
0.018
1.90
0.25
0.05
2.05
0.35
2.20
0.45
0.390
0.510
0.025
0.063
0.004
010
0.394
0.520
0.031
0.398
0.530
0.037
9.9
0.80
12.95
0.65
1.60
10.00
13.20
0.8
10.1
13.45
0.95
0.3980.394
0.390
0.530
0.520
0.510 13.4513.20
12.95
10.1
10.00
9.9
10
0
0.10
.0315
0.01 0.02 0.25 0.5
Seating Plane
11
22
12
See Detail F
eb
A
y1
AA
2
L
L1
c
EE
H
1
D
44
H
D
34
33
Detail F
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 87 - Revision A10
23.4 48-pin LQFP
W78E054D/W78E052D/W78E051D Data Sheet
- 88 -
24 REVISION HISTORY
VERSION DATE PAGE DESCRIPTION
A01 August 14,
2008 - Initial Issued
A02 November
3,2008 - Update DC table typing error.
A03 December
15,2008 - Update config bit table, and ISP BOOT
A04 January
7,2007 70 Update VIL and VIH .
A05 March 9, 2009 43 Update soft reset, only LD jump to AP function.
A06 March 20,
2009
18
-
-
1. Rename SFR Register POR (0x86H) to P0UPR.
2. Revise some typing errors in data sheet.
3. Update DC table
A07 April 22, 2009 68 1. Revise Type Application Circuit in data sheet.
A08 June 30, 2009
30
61
81
All Pages
1. Add the ISP control table.
2. Revise content of Char. 17.
3. Modify the ISP demo code.
4. Remove the “Preliminary” character for each page.
A09 Dec 30, 2009
68
77
1. Revise the “CONFIG BITS” description for Bit4, Bit6
and Bit7.
2. Add the timing for external reset pin.
A10 Oct 20, 2011
28
70
1. Revised the CHPCON description
2. Added description for “21.4 Reference Value of
XTAL
W78E054D/W78E052D/W78E051D Data Sheet
Publication Release Date: Oct 2 0, 2011
- 89 - Revision A10
Important Notice
Nuvoton Products are neither intende d nor warranted for usage in systems or equipment, any
malfunction or failure of which may cause loss of human life, bodily injury or severe property
damage. Such applications are deemed, “Insec ure Usage”.
Insecure usage includes, but is not limited to: equipment for surgical implementation, atomic
energy control instruments, airplane or spaceship instruments, the control or operation of dy-
namic, brake or safety systems designed for vehicular use, traffic signal instruments, all types
of safety devices, and other applicatio ns intended to support or sustain life.
All Insecure Usage shall be made at customer’s risk, and in the event that third parties lay
claims to Nuvoton as a result of customer’s Insecure Usage, customer shall indemnify the
damages and liabilities thus incurred by Nuvoton.
