Pioneer EFX-1000 Service Manual page 97

5
TC74VHC161FT (MAIN BOARD ASSY: IC413, IC414)
• Synchronous Presettable 4-bit Counter
PIn Assignment
Block Diagram
CLR
ENP
ENT
LOAD
TRUTH TABLE OF
INTERNAL F/F
5
6
CLR 1
CK 2
A 3
B 4
C 5
D 6
ENP 7
GND 8
(Top View)
1
7
10
9
3
A
L
L
4
B
L
5
C
L
6
D
2
CK
6
7
16 Vcc
15 CARRY OUTPUT
14 QA
13 QB
12 QC
11 QD
10 ENT
9 LOAD
E
E
L
L
R
D Q
E
CK
Q
E
L
E R
D Q
E
CK
Q
L
E
R
D Q
E
CK Q
L
E
R
D Q
E
CK Q
EFX-1000
7
8
15
CARRY
OUT
14
QA
13
QB
TC74VHC161
D CK R Q
X X H L
L L L
H L H
X L
12
NO CHANGE
QC
TC74VHC163
D CK R Q
X H L
L L L
H L H
X X
NO CHANGE
11
QD
X : Don't Care
8
A
B
C
D
Q
E
H
H
L
Q
H
H
L
F
97