W78E54C/W78E054C Data Sheet
8-BIT MICROCONTROLLER
Table of Contents-
1.
2.
3.
4.
5.
GENERAL DESCRIPTION ......................................................................................................... 3
FEATURES ................................................................................................................................. 3
PIN CONFIGURATIONS ............................................................................................................ 4
PIN DESCRIPTION..................................................................................................................... 5
FUNCTIONAL DESCRIPTION ................................................................................................... 6
5.1
5.2
Timers 0, 1, and 2 ........................................................................................................... 6
New Defined Peripheral.................................................................................................. 6
5.2.1
5.2.2
5.2.3
INT2
/
I
NT3
....................................................................................................................6
PORT4 .............................................................................................................................7
Reduce EMI Emission ......................................................................................................7
5.3
5.4
5.5
5.6
5.7
6.
Power-off Flag ................................................................................................................ 8
Watchdog Timer ............................................................................................................. 8
Clock ............................................................................................................................. 10
Power Management...................................................................................................... 10
Reset............................................................................................................................. 10
SECURITY BITS ....................................................................................................................... 11
6.1
6.2
6.3
Lock Bit ......................................................................................................................... 11
MOVC Inhibit................................................................................................................. 12
Encryption ..................................................................................................................... 12
7.
ELECTRICAL CHARACTERISTICS......................................................................................... 13
7.1
7.2
7.3
Absolute Maximum Ratings .......................................................................................... 13
D.C. Characteristics...................................................................................................... 13
A.C. Characteristics ...................................................................................................... 15
7.3.1
7.3.2
7.3.3
7.3.4
7.3.5
7.3.6
Clock Input Waveform ....................................................................................................15
Program Fetch Cycle......................................................................................................15
Data Read Cycle ............................................................................................................16
Data Write Cycle.............................................................................................................16
Port Access Cycle ..........................................................................................................16
Program Operation .........................................................................................................17
8.
TIMING WAVEFORMS ............................................................................................................. 18
Publication Release Date: October 3, 2006
Revision A4
-1-
W78E54C/W78E054C
8.1
8.2
8.3
8.4
9.
Program Fetch Cycle .................................................................................................... 18
Data Read Cycle........................................................................................................... 18
Data Write Cycle ........................................................................................................... 19
Port Access Cycle......................................................................................................... 19
TYPICAL APPLICATION CIRCUITS ........................................................................................ 20
9.1
9.2
Expanded External Program Memory and Crystal ....................................................... 20
Expanded External Data Memory and Oscillator ......................................................... 21
10.
PACKAGE DIMENSIONS ......................................................................................................... 22
10.1
10.2
10.3
40-pin DIP ..................................................................................................................... 22
44-pin PLCC ................................................................................................................. 22
44-pin PQFP ................................................................................................................. 23
11.
REVISION HISTORY ................................................................................................................ 24
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W78E54C/W78E054C
1. GENERAL DESCRIPTION
The W78E054C is an 8-bit microcontroller which can accommodate a wider frequency range with low
power consumption. The instruction set for the W78E054C is fully compatible with the standard 8051.
The W78E054C contains an 16K bytes Flash EPROM; a 256 bytes RAM; four 8-bit bi-directional 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 eight sources two-level interrupt
capability. To facilitate programming and verification, the Flash EPROM inside the W78E054C allows
the program memory to be programmed and read electronically. Once the code is confirmed, the user
can protect the code for security.
The W78E054C microcontroller has two power reduction modes, idle mode and power-down mode,
both of which are software selectable. The idle mode turns off the processor clock but allows for
continued peripheral operation. The power-down mode stops the crystal oscillator for minimum power
consumption. The external clock can be stopped at any time and in any state without affecting the
processor.
2. FEATURES
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Fully static design 8-bit CMOS microcontroller
Wide supply voltage of 4.5V to 5.5V
256 bytes of on-chip scratchpad RAM
16 KB electrically erasable/programmable Flash EPROM
64 KB program memory address space
64 KB data memory address space
Four 8-bit bi-directional ports
One extra 4-bit bit-addressable I/O port, additional
INT2
/
INT3
(available on 44-pin PLCC/QFP package)
Three 16-bit timer/counters
One full duplex serial port(UART)
Watchdog Timer
Eight sources, two-level interrupt capability
EMI reduction mode
Built-in power management
Code protection mechanism
Packages:
−
Lead Free (RoHS) DIP 40:
W78E054C40DL
−
Lead Free (RoHS) PLCC 44: W78E054C40PL
−
Lead Free (RoHS) PQFP 44: W78E054C40FL
-3-
Publication Release Date: October 3, 2006
Revision A4
W78E54C/W78E054C
3. PIN CONFIGURATIONS
-4-
W78E54C/W78E054C
4. PIN DESCRIPTION
SYMBOL
DESCRIPTIONS
EA
EXTERNAL ACCESS ENABLE:
This pin forces the processor to execute out of
external ROM. It should be kept high to access internal ROM. The ROM address and
data will not be presented on the bus if
EA
pin is high and the program counter is
within on-chip ROM area.
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.
ADDRESS LATCH ENABLE:
ALE is used to enable the address latch that separates
the address from the data on Port 0.
RESET:
A high on this pin for two machine cycles while the oscillator is running resets
the device.
CRYSTAL1:
This is the crystal oscillator input. This pin may be driven by an external
clock.
CRYSTAL2:
This is the crystal oscillator output. It is the inversion of XTAL1.
GROUND:
Ground potential
POWER SUPPLY:
Supply voltage for operation.
PORT 0:
Port 0 is a bi-directional I/O port which also provides a multiplexed low order
address/data bus during accesses to external memory. The Port 0 is also an open-
drain port and external pull-ups need to be connected while in programming.
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
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.
PORT 3:
Port 3 is a bi-directional I/O port with internal pull-ups. All bits have alternate
functions, which are described below:
RXD(P3.0) : Serial Port receiver input
TXD(P3.1) : Serial Port transmitter output
INT0
(P3.2) : External Interrupt 0
PSEN
ALE
RST
XTAL1
XTAL2
V
SS
V
DD
P0.0−P0.7
P1.0−P1.7
P2.0−P2.7
P3.0−P3.7
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
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
).
P4.0−P4.3
-5-
Publication Release Date: October 3, 2006
Revision A4
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