HD74HC149 Datasheet, PDF (2/9 Pages) Hitachi Semiconductor – 8-to-8-line Priority Encoder

HD74HC149
Function Table
Inputs
0 12 3 4 56 7 E
X XX X X XX X H
H HH H H HH H L
X XX X X XX L L
X XX X X XL HL
X XX X X L HHL
X XX X L HH H L
X XX L H HH H L
X XL H H HH H L
X L H H H HH H L
L HH H H HH H L
H : High level
L : Low level
X : Irrelevant
Outputs
Y₀ Y₁ Y₂ Y₃ Y₄ Y₅ Y₆ Y₇ P
H HH H HH H H H
H HH H HH H H H
H HH H HH H L L
H HH H HH L H L
H HH H HL H H L
H HH H L H H H L
H HH L HH H H L
H HL H HH H H L
H L H H HH H H L
L HH H HH H H L
Pin Arrangement
01
12
23
34
Inputs 4 5
56
67
78
E9
GND 10
(Top view)
20 VCC
19 Y0
18 Y1
17 Y2
16 Y3
15 Y4 Outputs
14 Y5
13 Y6
12 Y7
11 P
2