AT89S52 Atmel Corporation, AT89S52 Datasheet - Page 23

• Manufacturer Part Number: AT89S52
• Manufacturer: Atmel Corporation

Specifications of AT89S52

• Flash (kbytes): 8 Kbytes
• Max. Operating Frequency: 24 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Uart: 1
• Sram (kbytes): 0.25
• Operating Voltage (vcc): 4.0 to 5.5
• Timers: 3
• Isp: SPI
• Watchdog: Yes

22. Programming Interface – Parallel Mode
Table 22-1.
Notes:
1919D–MICRO–6/08
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.
Flash Programming Modes
V
5V
5V
5V
5V
5V
5V
5V
5V
5V
5V
CC
RST
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.
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
(2)
(3)
(3)
(3)
(1)
EA/
V
12V
12V
12V
12V
12V
PP
H
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
D
P0.2,
P0.3,
P0.4
1EH
52H
06H
D
OUT
X
X
X
X
IN
P2.4-0
X 0000
X 0001
X 0010
AT89S52
A12-8
A12-8
X
X
X
X
X
Address
P1.7-0
A7-0
A7-0
00H
00H
00H
X
X
X
X
X
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