SyncMOS Technologies International, Inc.

SM8951B

8-Bits Micro-controller

With4KBFlashROM&128bytesRAM embedded

Specifications subject to change without notice contact your sales representatives for the most recent information.

ISSFD-M022Ver:BSM8951B

06/2009

6

Pin Description

40L

PDIP

Pin

44L

PQFP

Pin

44L

PLCC

Pin

Symbol

Active

I/O

Names

1

40

2

P1.0

i/o

bit 0 of port 1

2

41

3

P1.1

i/o

bit 1 of port 1

3

42

4

P1.2

i/o

bit 2 of port 1

4

43

5

P1.3

i/o

bit 3 of port 1

5

44

6

P1.4

i/o

bit 4 of port 1

6

1

7

P1.5

i/o

bit 5 of port 1

7

2

8

P1.6

i/o

bit 6 of port 1

8

3

9

P1.7

i/o

bit 7 of port 1

9

4

10

RES

H

i

Reset

10

5

11

P3.0/RXD

i/o

bit 0 of port 3 & Receive data

11

6

13

P3.1/TXD

i/o

bit 1 of port 3 & Transmit data

12

7

14

P3.2/#INT0

L/ -

i/o

bit 2 of port 3 & low true interrupt 0

13

8

15

P3.3/#INT1

L/ -

i/o

bit 3 of port 3 & low true interrupt 1

14

9

16

P3.4/T0

i/o

bit 4 of port 3Timer 0

15

10

17

P3.5/T1

i/o

bit 5 of port 3 & Timer 1

16

11

18

P3.6/#WR

L/ -

i/o

bit 6 of port 3 & external memory write

17

12

19

P3.7/#RD

L/ -

i/o

bit 7 of port 3 & external memory read

18

13

20

XTAL2

o

Crystal out

19

14

21

XTAL1

i

Crystal in

20

15

22

VSS

Sink Voltage, Ground

21

16

24

P2.0/A8

i/o

bit 0 of port 2 & bit 8 of external memory address

22

19

25

P2.1/A9

i/o

bit 1 of port 2 & bit 9 of external memory address

23

20

26

P2.2/A10

i/o

bit 2 of port 2 & bit 10 of external memory address

24

21

27

P2.3/A11

i/o

bit 3 of port 2 & bit 11 of external memory address

25

22

28

P2.4/A12

i/o

bit 4 of port 2 & bit 12 of external memory address

26

23

29

P2.5/A13

i/o

bit 5 of port 2 & bit 13 of external memory address

27

24

30

P2.6/A14

i/o

bit 6 of port 2 & bit 14 of external memory address

28

25

31

P2.7/A15

i/o

bit 7 of port 2 & bit 15 of external memory address

29

26

32

#PSEN

L

o

Program Storage Enable

30

27

33

ALE

-

o

Address Latch Enable

31

29

35

#EA

L

i

External Access(If you are not using external memory,

please keep this pin to VCC)

32

30

36

P0.7/AD7

i/o

bit 7 of port 0 & data/address bit 7 of external memory

33

31

37

P0.6/AD6

i/o

bit 6 of port 0 & data/address bit 6 of external memory

34

32

38

P0.5/AD5

i/o

bit 5 of port 0 & data/address bit 5 of external memory

35

33

39

P0.4/AD4

i/o

bit 4 of port 0 & data/address bit 4 of external memory

36

34

40

P0.3/AD3

i/o

bit 3 of port 0 & data/address bit 3 of external memory

37

35

41

P0.2/AD2

i/o

bit 2 of port 0 & data/address bit 2 of external memory

38

36

42

P0.1/AD1

i/o

bit 1 of port 0 & data/address bit 1 of external memory

39

37

43

P0.0/AD0

i/o

bit 0 of port 0 & data/address bit 0 of external memory

40

38

44

VDD

Drive Voltage, Vcc