HD74HC651 Datasheet, PDF (2/9 Pages) Hitachi Semiconductor – Octal Bus Transceivers/Registers(with inverted 3-state outputs)

HD74HC651/HD74HC652
Function Table
Clock AB
Select AB
Enable GAB
Clock BA
Select BA
Enable GBA
Real-Time Transfer Real-Time Transfer
Bus B to Bus A
Bus A to Bus B
Storage
X
X
X
L
X
L
H
L
X
X
L
X
X
L
H
H
Transfer Stored
Data to A and/or B
L or H
H
H
L or H
H
L
Real-time transfer
Bus B to Bus A
Real-time transfer
Bus A to Bus B
2