AT89C55WD Atmel Corporation, AT89C55WD Datasheet - Page 3

• Manufacturer Part Number: AT89C55WD
• Manufacturer: Atmel Corporation

Specifications of AT89C55WD

• Flash (kbytes): 20 Kbytes
• Max. Operating Frequency: 24 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Uart: 1
• Sram (kbytes): 0.25
• Operating Voltage (vcc): 4.0 to 6.0
• Timers: 3
• Watchdog: Yes

3. Block Diagram
1921D–MICRO–6/08
ALE/PROG
EA / V
PSEN
RST
V
GND
PP
CC
CONTROL
REGISTER
TIMING
AND
OSC
B
RAM ADDR.
REGISTER
INSTRUCTION
REGISTER
WATCH
DOG
ACC
TMP2
RAM
PORT 1 DRIVERS
PSW
P1.0 - P1.7
PORT 0 DRIVERS
PORT 1
LATCH
ALU
P0.0 - P0.7
PORT 0
LATCH
TMP1
INTERRUPT, SERIAL PORT,
AND TIMER BLOCKS
PORT 2
LATCH
PORT 3 DRIVERS
PORT 2 DRIVERS
POINTER
P2.0 - P2.7
STACK
P3.0 - P3.7
PORT 3
LATCH
QUICK
FLASH
INCREMENTER
PROGRAM
PROGRAM
REGISTER
COUNTER
ADDRESS
BUFFER
DPTR
DUAL
PC
AT89C55WD
3