Programming interface, At89c55wd, Table 10. flash programming modes – Rainbow Electronics AT89C55WD User Manual
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AT89C55WD
1921B–MICRO–09/02
Programming
Interface
Every code byte in the Flash array can be programmed by using the appropriate combination
of control signals. The write operation cycle is self-timed and once initiated, will automatically
time itself to completion.
Most worldwide major programming vendors offer support for the Atmel microcontroller series.
Please contact your local programming vendor for the appropriate software revision.
Notes:
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.
Table 10. Flash Programming Modes
Mode
V
CC
RST
PSEN
ALE/
PROG
EA/
V
PP
P2.6
P2.7
P3.3
P3.6
P3.7
P0.7-0
Data
P3.4
P2.5-0
P1.7-0
Address
Write Code Data
5V
H
L
12V
L
H
H
H
H
D
IN
A14
A13-8
A7-0
Read Code Data
5V
H
L
H
H/12V
L
L
L
H
H
D
OUT
A14
A13-8
A7-0
Write Lock Bit 1
6.5V
H
L
12V
H
H
H
H
H
X
X
X
X
Write Lock Bit 2
6.5V
H
L
12V
H
H
H
L
L
X
X
X
X
Write Lock Bit 3
6.5V
H
L
12V
H
L
H
H
L
X
X
X
X
Read Lock Bits
1, 2, 3
5V
H
L
H
H
H
H
L
H
L
P0.2,
P0.3,
P0.4
X
X
X
Chip Erase
6.5V
H
L
12V
H
L
H
L
L
X
X
X
X
Read Atmel ID
5V
H
L
H
H
L
L
L
L
L
1EH
X
XX 0000
00H
Read Device ID
5V
H
L
H
H
L
L
L
L
L
55H
X
XX 0001
00H
Read Device ID
5V
H
L
H
H
L
L
L
L
L
06H
X
XX 0010
00H