AT89C55WD-33AC ATMEL Corporation, AT89C55WD-33AC Datasheet - Page 23

• Manufacturer Part Number: AT89C55WD-33AC
• Description: 8-bit Microcontroller with 20K Bytes Flash
• Manufacturer: ATMEL Corporation

Programming
Interface
Table 10. Flash Programming Modes
Notes:
1921B–MICRO–09/02
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.
V
6.5V
6.5V
6.5V
6.5V
5V
5V
5V
5V
5V
5V
CC
RST
H
H
H
H
H
H
H
H
H
H
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.
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
PP
H
H
H
H
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
AT89C55WD
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
X
X
X
X
X
P1.7-0
A7-0
A7-0
00H
00H
00H
X
X
X
X
X
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