Philips Semiconductors

Product specification

80C451/83C451/87C451

80C51 8-bit microcontroller family

4K/128 OTP/ROM/ROMless, expanded I/O

2

1998 May 01

853-0830 19327

DESCRIPTION

The Philips 8XC451 is an I/O expanded single-chip microcontroller

fabricated with Philips high-density CMOS technology. Philips

epitaxial substrate minimizes latch-up sensitivity.

The 8XC451 (includes the 80C451, 87C451 and 83C451) is a

functional extension of the 87C51 microcontroller with three

additional I/O ports and four I/O control lines for a total of 68 pins.

Four control lines associated with port 6 facilitate high-speed

asynchronous I/O functions.

The 8XC451 includes a 4k

× 8 ROM (83C451) EPROM (87C451), a

128

× 8 RAM, 56 I/O, two 16-bit timer/counters, a five source, two

priority level, nested interrupt structure, a serial I/O port for either a

full duplex UART, I/O expansion, or multi-processor

communications, and on-chip oscillator and clock circuits. The

80C451 ROMless version includes all of the 83C451 features except

the on-board 4k

× 8 ROM.

The 87C451 has 4k of EPROM on-chip as program memory and is

otherwise identical to the 83C451.

The 8XC451 has two software selectable modes of reduced activity

for further power reduction; idle mode and power-down mode. Idle

mode freezes the CPU while allowing the RAM, timers, serial port,

and interrupt system to continue functioning. Power-down mode

freezes the oscillator, causing all other chip functions to be

inoperative while maintaining the RAM contents.

FEATURES

– Eight data pins

– Four control pins

– Direct MPU bus interface

– Parallel printer interface

– 4k

× 8 ROM (83C451)

4k

× 8 EPROM (87C451)

ROMless version (80C451)

– 128

× 8 RAM

– Two 16-bit counter/timers

– Two external interrupts

– 64k ROM and 64k RAM

– Normal operation: less than 24mA at 5V, 12MHz

– Idle mode

– Power-down mode

PIN CONFIGURATION

LCC

91

61

10

26

60

44

27

43

Pin

Function

1EA/VPP

2

P2.0/A8

3

P2.1/A9

4

P2.2/A10

5

P2.3/A11

6

P2.4/A12

7

P2.5/A13

8

P2.6/A14

9

P2.7/A15

10

P0.7/AD7

11

P0.6/AD6

12

P0.5/AD5

13

P0.4/AD4

14

P0.3/AD3

15

P0.2/AD2

16

P0.1/AD1

17

P0.0/AD0

18

19

P4.7

20

P4.6

21

P4.5

22

P4.4

23

P4.3

Pin

Function

24

P4.2

25

P4.1

26

P4.0

27

P1.0

28

P1.1

29

P1.2

30

P1.3

31

P1.4

32

P1.5

33

P1.6

34

P1.7

35

RST

36

P3.0/RxD

37

P3.1/TxD

38

P3.2/INT0

39

P3.3/INT1

40

P3.4/T0

41

P3.5/T1

42

P3.6/WR

43

P3.7/RD

44

P5.0

45

P5.1

46

P5.2

Pin

Function

47

P5.3

48

P5.4

49

P5.5

50

P5.6

51

P5.7

52

XTAL2

53

XTAL1

54

55

ODS

56

IDS

57

BFLAG

58

AFLAG

59

P6.0

60

P6.1

61

P6.2

62

P6.3

63

P6.4

64

P6.5

65

P6.6

66

P6.7

67

PSEN

68

ALE/PROG

SU00084A