AT89C51-20PI

Manufacturer Part NumberAT89C51-20PI
Description8-bit microcontroller with 4K bytes flash, 5V, 20MHz
ManufacturerATMEL Corporation
AT89C51-20PI datasheet
 


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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
bytes of Flash programmable and erasable read only memory (PEROM). The device
is manufactured using Atmel’s high-density nonvolatile memory technology and is
compatible with the industry-standard MCS-51 instruction set and pinout. The on-chip
Flash allows the program memory to be reprogrammed in-system or by a conven-
tional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash
on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer which provides
a highly-flexible and cost-effective solution to many embedded control applications.
Pin Configurations
PQFP/TQFP
P1.5
1
P1.6
2
P1.7
3
RST
4
(RXD) P3.0
5
NC
6
(TXD) P3.1
7
(INT0) P3.2
8
(INT1) P3.3
9
(T0) P3.4
10
(T1) P3.5
11
PDIP
P1.0
1
P1.1
2
P1.2
3
P1.3
4
P1.4
5
P1.5
6
P1.6
7
P1.7
8
RST
9
(RXD) P3.0
10
(TXD) P3.1
11
(INT0) P3.2
12
(INT1) P3.3
13
(T0) P3.4
14
(T1) P3.5
15
(WR) P3.6
16
(RD) P3.7
17
XTAL2
18
XTAL1
19
33
PO.4 (AD4)
GND
20
32
P0.5 (AD5)
31
P0.6 (AD6)
PLCC
30
P0.7 (AD7)
29
EA/VPP
28
NC
27
ALE/PROG
26
PSEN
25
P2.7 (A15)
24
P2.6 (A14)
23
P2.5 (A13)
P1.5
7
P1.6
8
P1.7
9
RST
10
(RXD) P3.0
11
NC
12
(TXD) P3.1
13
(INT0) P3.2
14
(INT1) P3.3
15
(T0) P3.4
16
(T1) P3.5
17
8-bit
Microcontroller
with 4K Bytes
Flash
AT89C51
Not Recommended
for New Designs.
40
VCC
39
P0.0 (AD0)
Use AT89S51.
38
P0.1 (AD1)
37
P0.2 (AD2)
36
P0.3 (AD3)
35
P0.4 (AD4)
34
P0.5 (AD5)
33
P0.6 (AD6)
32
P0.7 (AD7)
31
EA/VPP
30
ALE/PROG
29
PSEN
28
P2.7 (A15)
27
P2.6 (A14)
26
P2.5 (A13)
25
P2.4 (A12)
24
P2.3 (A11)
23
P2.2 (A10)
22
P2.1 (A9)
21
P2.0 (A8)
39
PO.4 (AD4)
38
P0.5 (AD5)
37
P0.6 (AD6)
36
P0.7 (AD7)
35
EA/VPP
34
NC
33
ALE/PROG
32
PSEN
31
P2.7 (A15)
30
P2.6 (A14)
29
P2.5 (A13)
Rev. 0265G–02/00
1

AT89C51-20PI Summary of contents