HD74HC646 Datasheet, PDF (3/10 Pages) Hitachi Semiconductor – Octal Bus Transceivers/Registers with Multiplexed 3-state outputs

HD74HC646/HD74HC648
Storage from
A, B, or A and B
Pin Arrangement
Transfer stored data
to A or B
Clock AR 1
Select AB 2
Direciton 3
A₁ 4
A2 5
A3 6
A4 7
A5 8
A6 9
A7 10
A8 11
GND 12
24 VCC
23 Clock BA
22 Select BA
21 Control G
20 B₁
19 B₂
18 B₃
17 B₄
16 B₅
15 B₆
14 B₇
13 B₈
(Top view)
3