HD74HC155 Datasheet, PDF (2/7 Pages) Hitachi Semiconductor – Dual 2-to-4-line Decoders/Demultiplexers

HD74HC155
Function Table
2-line-to-4-line Decoder/1-line-to-4-line Demultiplexer
Inputs
Select
Strobe
Data
B
A
1G
1C
1Y0
X
X
H
X
H
L
L
L
H
L
L
H
L
H
H
H
L
L
H
H
H
H
L
H
H
X
X
X
L
H
Inputs
Select
Strobe
Data
B
A
2G
2C
2Y0
X
X
H
X
H
L
L
L
L
L
L
H
L
L
H
H
L
L
L
H
H
H
L
L
H
X
X
X
H
H
H : High level
L : Low level
X : Irrelevant
3-line-to-8-line Decoder/1-line-to-8-line Demultiplexer
Inputs
Select
Strobe Data 0
1
2
C
B
A
G
2Y0
2Y1
2Y2
X
X
X
H
H
H
H
L
L
L
L
L
H
H
L
L
H
L
H
L
H
L
H
L
L
H
H
L
L
H
H
L
H
H
H
H
L
L
L
H
H
H
H
L
H
L
H
H
H
H
H
L
L
H
H
H
H
H
H
L
H
H
H
Notes: 1. C: inputs 1C and 2C connected together
2. G: inputs 1G and 2G connected together
3. X: irrelevant
Outputs
1Y1
1Y2
1Y3
H
H
H
H
H
H
L
H
H
H
L
H
H
H
L
H
H
H
Outputs
2Y1
2Y2
2Y3
H
H
H
H
H
H
L
H
H
H
L
H
H
H
L
H
H
H
Outputs
3
4
5
6
7
2Y3
1Y0
1Y1
1Y2
1Y3
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
L
H
H
H
H
H
L
H
H
H
H
H
L
H
H
H
H
H
L
H
H
H
H
H
L
Rev.2.00, Oct 11, 2005 page 2 of 6