1
PQFP/TQFP
1
2
3
4
5
6
7
8
9
10
11
33
32
31
30
29
28
27
26
25
24
23
P1.
5
P1.
6
P1.
7
RST
(RXD) P3.
0
NC
(TXD) P3.
1
(INT0) P3.
2
(INT1) P3.
3
(T0) P3.
4
(T1) P3.
5
PO.
4 (AD4)
P0.
5 (AD5)
P0.
6 (AD6)
P0.
7 (AD7)
EA/VPP
NC
ALE/PROG
PSEN
P2.
7 (A15)
P2.
6...
More
1
PQFP/TQFP
1
2
3
4
5
6
7
8
9
10
11
33
32
31
30
29
28
27
26
25
24
23
P1.
5
P1.
6
P1.
7
RST
(RXD) P3.
0
NC
(TXD) P3.
1
(INT0) P3.
2
(INT1) P3.
3
(T0) P3.
4
(T1) P3.
5
PO.
4 (AD4)
P0.
5 (AD5)
P0.
6 (AD6)
P0.
7 (AD7)
EA/VPP
NC
ALE/PROG
PSEN
P2.
7 (A15)
P2.
6 (A14)
P2.
5 (A13)
44
43
42
41
40
39
38
37
36
35
34
12
13
14
15
16
17
18
19
20
21
22
(WR)P3.
6
(RD)P3.
7
XTAL2
XTAL1
GND
GND
(A8)P2.
0
(A9)P2.
1
(A10)P2.
2
(A11)P2.
3
(A12)P2.
4
P1.
4
P1.
3
P1.
2
P1.
1(T2EX)
P1.
0(T2)
NC
VCC
P0.
0(AD0)
P0.
1(AD1)
P0.
2(AD2)
P0.
3(AD3)
Features
• Compatible with MCS-51™
Products
• 4K Bytes of In-System Reprogrammable Flash Memory
– Endurance: 1,000 Write/Erase Cycles
• Fully Static Operation: 0 Hz to 24 MHz
• Three-level Program Memory Lock
• 128 x 8-bit Internal RAM
• 32 Programmable I/O Lines
• Two 16-bit Timer/Counters
• Six Interrupt Sources
• Programmable Serial Channel
• Low-power Idle and Power-down Modes
Description
The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K
by
Less
