Rainbow Electronics AT89C55WD - Manual (Page 3)

3
AT89C55WD
1921B–MICRO–09/02
Block Diagram
PORT 2 DRIVERS
PORT 2
LATCH
P2.0 - P2.7
QUICK
FLASH PORT 0
LATCH
RAM
PROGRAM
ADDRESS
REGISTER
BUFFER
PC
INCREMENTER
PROGRAM
COUNTER
DUAL
DPTR
RAM ADDR.
REGISTER
INSTRUCTION
REGISTER
B
REGISTER
INTERRUPT, SERIAL PORT,
AND TIMER BLOCKS
STACK
POINTER
ACC
TMP2 TMP1
ALU
PSW
TIMING
AND
CONTROL
PORT 3
LATCH
PORT 3 DRIVERS
P3.0 - P3.7
PORT 1
LATCH
PORT 1 DRIVERS
P1.0 - P1.7
OSC
GND
V
CC
PSEN
ALE/PROG
EA / V
PP
RST
PORT 0 DRIVERS
P0.0 - P0.7
WATCH
DOG