at89c51-12qi ATMEL Corporation, at89c51-12qi Datasheet - Page 7

• Manufacturer Part Number: at89c51-12qi
• Description: 8-bit Microcontroller With 4k Bytes Flash
• Manufacturer: ATMEL Corporation

Flash Programming Modes
Note:
Figure 3. Programming the Flash
Mode
Write Code Data
Read Code Data
Write Lock
Chip Erase
Read Signature Byte
PROGRAMMING
MODES ABLE
3-24 MHz
SEE FLASH
OOOOH/OFFFH
1. Chip Erase requires a 10 ms PROG pulse.
ADDR.
T
A0 - A7
A8 - A11
Bit - 1
Bit - 2
Bit - 3
P1
P2.0 - P2.3
P2.6
P2.7
P3.6
P3.7
XTAL2
XTAL1
GND
AT89C51
RST
H
H
H
H
H
H
H
PSEN
RST
ALE
V
EA
P0
CC
PSEN
L
L
L
L
L
L
L
+5V
PGM
DATA
PROG
V /V
V
IH
IH
PP
ALE/PROG
Figure 4. Verifying the Flash
H
H
3-24 MHz
PROGRAMMING
MODES ABLE
SEE FLASH
OOOOH/0FFFH
(1)
ADDR.
T
EA/V
H/12V
H/12V
H/12V
H/12V
H/12V
A0 - A7
A8 - A11
H
H
PP
P1
P2.0 - P2.3
P2.6
P2.7
P3.6
P3.7
XTAL2
XTAL1
GND
P2.6
H
H
H
H
L
L
L
AT89C51
P2.7
H
H
H
L
L
L
L
PSEN
RST
ALE
V
EA
P0
CC
P3.6
H
H
H
H
L
L
L
+5V
PGM DATA
(USE 10K
PULLUPS)
V
P3.7
V
IH
IH
H
H
H
L
L
L
L
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