www.fairchildsemi.com

2

Pin Assignment for

DIP and SOIC Package

Top View

MM74C923

Truth Tables

(Pins 0 through 11)

(Pins 12 through 19)

Note 1: Omit for MM74C922

Switch

01234

5

6

7

8

9

10

11

Position

Y1, X1 Y1, X2 Y1, X3 Y1, X4 Y2, X1 Y2, X2

Y2, X3 Y2, X4

Y3, X1

Y3, X2

Y3, X3

Y3, X4

D

A

A

010101

0

1

0

1

0

1

T

B

001100

1

1

0

0

1

1

A

C

000011

1

1

0

0

0

0

O

D

000000

0

0

1

1

1

1

U

E (Note 1)

000000

0

0

0

0

0

0

T

Switch

12

13

14

15

16

17

18

19

Position

Y4, X1

Y4, X2

Y4, X3

Y4, X4

Y5(Note 1), X1 Y5 (Note 1), X2 Y5 (Note 1), X3 Y5 (Note 1), X4

D

A

A

010

1

0

1

0

1

T

B

001

1

0

0

1

1

A

C

111

1

0

0

0

0

O

D

111

1

0

0

0

0

U

E (Note 1)

0

0

0

0

1

1

1

1

T