AT89C55WD Atmel Corporation, AT89C55WD Datasheet - Page 29

• 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

31. External Data Memory Write Cycle
32. External Clock Drive Waveforms
33. External Clock Drive
1921D–MICRO–6/08
Symbol
1/t
t
t
t
t
t
CLCL
CHCX
CLCX
CLCH
CHCL
CLCL
0.45V
V
CC
PORT 0
PORT 2
- 0.5V
Parameter
Oscillator Frequency
Clock Period
High Time
Low Time
Rise Time
Fall Time
PSEN
ALE
WR
0.2 V
0.7 V
CC
A0 - A7 FROM RI OR DPL
- 0.1V
CC
t
t
LHLL
CHCX
t
AVLL
P2.0 - P2.7 OR A8 - A15 FROM DPH
t
AVWL
t
LLAX
t
QVWX
t
LLWL
Min
t
DATA OUT
30
12
12
t
CLCX
0
t
QVWH
WLWH
t
CLCH
t
WHQX
t
t
A0 - A7 FROM PCL
CLCL
WHLH
A8 - A15 FROM PCH
Max
33
5
5
t
CHCX
INSTR IN
AT89C55WD
Units
MHz
ns
ns
ns
ns
ns
t
CHCL
29