General Description

The ABT899 is a 9-bit to 9-bit parity transceiver with transparent latches. The device can operate as a feed-through transceiver or it can generate/check parity from the 8-bit data busses in either direction.

The ABT899 features independent latch enables for the A-to-B direction and the B-to-A direction, a select pin for ODD/EVEN parity, and separate error signal output pins for checking parity.

Features

■ Latchable transceiver with output sink of 64 mA

■ Option to select generate parity and check or

“feed-through” data/parity in directions A-to-B or B-to-A

■ Independent latch enables for A-to-B and B-to-A directions

■ Select pin for ODD/EVEN parity

■ ERRA and ERRB output pins for parity checking

■ Ability to simultaneously generate and check parity

■ May be used in systems applications in place of the 543 and 280

■ May be used in system applications in place of the

657 and 373 (no need to change T/R to check parity)

■ Guaranteed output skew

■ Guaranteed multiple output switching specifications

■ Output switching specified for both 50 pF and 250 pF loads

■ Guaranteed simultaneous switching noise level and

dynamic threshold performance

■ Guaranteed latchup protection

■ High impedance glitch free bus loading during entire

power up and power down cycle

■ Nondestructive hot insertion capability

■ Disable time less than enable time to avoid bus contention