74F621

The 74F621 is an octal transceiver featuring non-inverting open collector bus-compatible outputs in both send and receive directions. The outputs are capable of sinking 64mA, providing very good capacitive drive characteristics.

This octal bus transceiver of the 74F621 is designed for asynchronous two-way communication between data buses. The control function implementation allows for maximum flexibility in timing.

The 74F621 allows data transmission from the A bus to the B bus or from the B bus to the A bus, depending upon the logic levels at the Enable inputs (OEBA and OEAB). The Enable inputs can be used to disable the device so that the buses are effectively isolated.

The dual-enable configuration gives the 74F621 the capability to store data by the simultaneous enabling of OEBA and OEAB. Each output reinforces its input in this transceiver configuration. Thus,when both control inputs of the 74F621 are enabled and all other data sources to the two sets of the bus lines are at high impedance, both sets of bus lines (16 in all) will remain in their last states.