
Fairchild Semiconductor
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