at89c55wd-33pc ATMEL Corporation, at89c55wd-33pc Datasheet - Page 22

• Manufacturer Part Number: at89c55wd-33pc
• Description: At89c55wd Microcontroller With 20k Bytes Flash
• Manufacturer: ATMEL Corporation

Table 21-1.
Notes:
22
Mode
Write Code
Data
Read Code
Data
Write Lock Bit
1
Write Lock Bit
2
Write Lock Bit
3
Read Lock Bits
1, 2, 3
Chip Erase
Read Atmel ID
Read Device
ID
Read Device
ID
1. Write Code Data requires a 200 ns PROG pulse.
2. Write Lock Bits requires a 100 µs PROG pulse.
3. Chip Erase requires a 200 ns - 500 ns PROG pulse.
4. RDY/BSY signal is output on P3.0 during programming.
AT89C55WD
Flash Programming Modes
V
6.5
6.5
6.5
6.5
5V
5V
5V
5V
5V
5V
CC
V
V
V
V
RST
H
H
H
H
H
H
H
H
H
H
PSEN
L
L
L
L
L
L
L
L
L
L
PROG
ALE/
H
H
H
H
H
(1)
(2)
(2)
(2)
(3)
H/12V
EA/
V
12V
12V
12V
12V
12V
H
H
H
H
PP
P2.6
H
H
H
H
H
L
L
L
L
L
P2.7
H
H
H
H
L
L
L
L
L
L
P3.3
H
H
H
H
H
L
L
L
L
L
P3.6
H
H
H
H
H
L
L
L
L
L
P3.7
H
H
H
L
L
L
L
L
L
L
P0.7-0
Data
P0.2,
P0.3,
D
P0.4
1EH
55H
06H
D
OUT
X
X
X
X
IN
P3.4
A14
A14
X
X
X
X
X
X
X
X
XX 0000
XX 0001
XX 0010
Address
P2.5-0
A13-8
A13-8
1921C–MICRO–3/05
X
X
X
X
X
P1.7-0
A7-0
A7-0
00H
00H
00H
X
X
X
X
X