AT89C55WD Atmel Corporation, AT89C55WD Datasheet - Page 25

• 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

23. Flash Programming and Verification Waveforms
24. Lock Bit Programming
25. Parallel Chip Erase Mode
1921D–MICRO–6/08
Test Conditions
ALE/PROG
V
Lockbit_1, 2 or 3
CC
Test Conditions
P3<0>
Setup
= 6.5V
V
ALE/PROG
Data Setup
CC
P1.0 - P1.7
P2.0 - P2.5
ALE/PROG
(RDY/BSY)
(ENABLE)
= 6.5V
Setup
PORT 0
P3.0
P2.7
EA/V
200 ns
P3.4
PP
Erase
t
t
SHGL
AVGL
Erase
DC
t
EHSH
V
PROGRAMMING
PP
t
DVGL
ADDRESS
100 µs
DATA IN
t
GLGH
t
GHBL
t
GHDX
10 ms
t
ELQV
t
200 ns
GHAX
t
GHSL
LOGIC 1
LOGIC 0
BUSY
Test Conditions Setup
t
WC
Erase
VERIFICATION
DATA OUT
ADDRESS
t
AVQV
READY
V
CC
Wait 10 ms to reload
new lock bit status
Erase
DC
= 4.5V to 5.5V
t
V
EHQZ
CC
AT89C55WD
= 4.5V to 5.5V
Wait 10 ms before
reprogramming
25