AT89C2051 Datasheet, PDF (9/20 Pages) ATMEL Corporation – 8-Bit Microcontroller with 2K Bytes Flash

AT89C2051
12. Programming Interface
Every code byte in the Flash array can be written and the entire array can be erased 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.
13. Flash Programming Modes
Mode
RST/VPP
Write Code Data⁽¹⁾⁽³⁾
12V
Read Code Data⁽¹⁾
H
Write Lock
Bit - 1
12V
Bit - 2
12V
P3.2/PROG
H
P3.3
L
L
H
P3.4
H
L
H
P3.5
H
H
H
P3.7
H
H
H
H
H
L
L
Chip Erase
12V
(2)
H
L
L
L
Read Signature Byte
H
H
L
L
L
L
Notes:
1. The internal PEROM address counter is reset to 000H on the rising edge of RST and is advanced by a positive pulse at
XTAL1 pin.
2. Chip Erase requires a 10 ms PROG pulse.
3. P3.1 is pulled Low during programming to indicate RDY/BSY.
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0368G–MICRO–6/05