The 'ABT16543 16-bit registered transceivers contain two sets of
D-type latches for temporary storage of data flowing in either
direction. The 'ABT16543 can be used as two 8-bit transceivers or one
16-bit transceiver. Separate latch-enable ( or) and output-enable ( or ) inputs are
provided for each register to permit independent control in either
direction of data flow.
The A-to-B enable ()
input must be low to enter data from A or to output data from B. If
is low and is low, the A-to-B latches are
transparent; a subsequent low-to-high transition of puts the A latches in the storage
mode. With and both low, the 3-state B outputs are
active and reflect the data present at the output of the A latches.
Data flow from B to A is similar but requires using the,, and inputs.
To ensure the high-impedance state during power up or power down,
should be tied
to VCC through a pullup resistor; the minimum value of the
resistor is determined by the current-sinking capability of the
The SN54ABT16543 is characterized for operation over the full
military temperature range of -55°C to 125°C. The
SN74ABT16543 is characterized for operation from -40°C to