AT89S51-24SC ATMEL Corporation, AT89S51-24SC Datasheet - Page 14

• Manufacturer Part Number: AT89S51-24SC
• Description: 8-bit Microcontroller with 4K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

Serial
Programming
Instruction Set
Programming
Interface –
Parallel Mode
Table 7. Flash Programming Modes
Notes:
14
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. 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.
AT89S51
V
5V
5V
5V
5V
5V
5V
5V
5V
5V
5V
CC
RST
H
H
H
H
H
H
H
H
H
H
Power-off sequence (if needed):
Data Polling: The Data Polling feature is also available in the serial mode. In this mode, dur-
ing a write cycle an attempted read of the last byte written will result in the complement of the
MSB of the serial output byte on MISO.
The Instruction Set for Serial Programming follows a 4-byte protocol and is shown in Table 8.
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 worldwide support for the Atmel AT89
microcontroller series. Please contact your local programming vendor for the appropriate soft-
ware revision.
Set XTAL1 to “L” (if a crystal is not used).
Set RST to “L”.
Turn V
PSEN
L
L
L
L
L
L
L
L
L
L
CC
PROG
ALE/
power off.
H
H
H
H
H
(2)
(3)
(3)
(3)
(1)
EA/
V
12V
12V
12V
12V
12V
H
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
D
1EH
51H
06H
P0.2,
P0.3,
P0.4
D
OUT
X
X
X
X
IN
P2.3-0
A11-8
A11-8
0000
0001
0010
2487B–MICRO–12/03
X
X
X
X
X
Address
P1.7-0
A7-0
A7-0
00H
00H
00H
X
X
X
X
X