W78E51B Winbond, W78E51B Datasheet - Page 4

• Manufacturer Part Number: W78E51B
• Description: 8-BIT MTP MICROCONTROLLER
• Manufacturer: Winbond

BLOCK DIAGRAM
FUNCTIONAL DESCRIPTION
The W78E51B architecture consists of a core controller surrounded by various registers, five general
purpose I/O ports, 128 bytes of RAM, two timer/counters, and a serial port. The processor supports
111 different opcodes and references both a 64K program address space and a 64K data storage
space.
New Defined Peripheral
In order to be more suitable for I/O, an extra 4-bit bit-addressable port P4 and two external interrupt
INT2 , INT3 has been added to either the PLCC or QFP 44 pin package. And description follows:
P1.0
P1.7
P3.0
P3.7
P4.3
P4.0
~
~
~
INT2
INT3
Port
1
Port
Port
3
4
Interrupt
UART
Port 3
Port 4
Port 1
Timer
Timer
Latch
Latch
Latch
0
1
XTAL1
Oscillator
XTAL2
PSW
Bus & Clock
Instruction
Sequencer
Controller
Decoder
ALE
ACC
&
T1
PSEN
ALU
Reset Block
Watchdog
SFR RAM
RAM & SFR
Timer
- 4 -
Address
128 bytes
ROM
RST
T2
B
Pointer
Stack
Power control
Vcc
Preliminary W78E51B
Vss
Temp Reg.
Addr. Reg.
Incrementor
DPTR
PC
Port 0
Latch
Port 2
Latch
Port
Port
2
0
P0.0
P0.7
P2.0
P2.7
~
~