Function Table - Denon S-81 Service Manual

TC7WH157FU (IC308 : 1U-3760)
Vcc ST SELECT
8 7
1 2
A B
SN74LV244A (IC309 : 1U-3760)
1OE
1A1
2Y4
1A2
2Y3
1A3
2Y2
1A4
2Y1
GND
logic diagram (positive logic)
1
1OE
2
1A1
4
1A2
6
1A3
8
1A4
Y
6 5
3 4
Y GND
(TOP VIEW)
V
1
20
CC
2OE
2
19
1Y1
3
18
4 2A4
17
1Y2
5
16
2A3
6
15
7 1Y3
14
8 2A2
13
9 1Y4
12
10 2A1
11
1 8
1 6
1 4
1 2

FUNCTION TABLE

(each buffer)
INPUTS
OE
L
L
H
19
2OE
11
1Y1
2A1
13
1Y2 2A2
15
1Y3 2A3
17
1Y4
2A4
37
S-81/S-81DAB
OUTPUT
OUTPUT
Y
A
H H
L L
X Z
9
2Y1
7
2Y2
5
2Y3
3
2Y4