Datasheet

23
1919C–MICRO–3/05
AT89S52
22. Programming Interface – Parallel Mode
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 major worldwide programming vendors offer support for the Atmel AT89 microcontroller
series. Please contact your local programming vendor for the appropriate software revision.
Notes: 1. Each PROG pulse is 200 ns - 500 ns for Chip Erase.
2. Each PROG
pulse is 200 ns - 500 ns for Write Code Data.
3. Each PROG
pulse is 200 ns - 500 ns for Write Lock Bits.
4. RDY/BSY
signal is output on P3.0 during programming.
5. X = don’t care.
Table 22-1. 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
P2.4-0 P1.7-0
Address
Write Code Data 5V H L
(2)
12V LHHHH D
IN
A12-8 A7-0
Read Code Data 5V H L H H L L L H H D
OUT
A12-8 A7-0
Write Lock Bit 1 5V H L
(3)
12VHHHHH X X X
Write Lock Bit 2 5V H L
(3)
12V H H H L L X X X
Write Lock Bit 3 5V H L
(3)
12V H L H H L 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
XX
Chip Erase 5V H L
(1)
12VHLHLL X X X
Read Atmel ID 5V H L H H LLLLL 1EHX 0000 00H
Read Device ID 5V H L H H LLLLL 52HX 0001 00H
Read Device ID 5V H L H H LLLLL 06HX 0010 00H