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MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
Octal 3-State Inverting Bus Transceiver
High–Performance Silicon–Gate CMOS
The MC54/74HC640A is identical in pinout to the LS640. The device inputs are compatible with standard CMOS outputs; with pullup resistors, they are compatible with LSTTL outputs.
The HC640A is a 3–state transceiver that is used for 2–way asynchronous communication between data buses. The device has an active–low Output Enable pin, which is used to place the I/O ports into high–impedance states. The Direction control determines whether data flows from A to B or from B to A.
MC54HC640A Datasheet
