• BiCMOS Process With TTL Inputs and
Outputs
• State-of-the-Art BiCMOS Design
Significantly Reduces Standby Current
• Flow-Through Pinout (All Inputs on
Opposite Side From Outputs)
• Functionally Equivalent to AMD Am29854
• High-Speed Bus Transceiver With Parity
Generator/Checker
• Parity-Error Flag With Open-Collector
Output
• Latch for Storage of the Parity-Error Flag
• Package Options Include Plastic
Small-Outline (DW) Packages and Standard
Plastic 300-mil DIPs (NT)

description
The SN74BCT29854 is an 8-bit to 9-bit parity transceiver designed for asynchronous communication between
data buses. When data is transmitted from the A to B bus, a parity bit is generated. When data is transmitted
from the B to A bus with its corresponding parity bit, the parity-error (ERR) output will indicate whether or not
an error in the B data has occurred. The output-enable (OEA, OEB) inputs can be used to disable the device
so that the buses are effectively isolated.
A 9-bit parity generator/checker generates a parity-odd (PARITY) output and monitors the parity of the I/O ports
with an open-collector parity-error (ERR) flag. ERR can be either passed, sampled, stored, or cleared from the
latch using the latch-enable (LE) and clear (CLR) control inputs. When both OEA and OEB are low, data is
transferred from the A bus to the B bus and inverted parity is generated. Inverted parity is a forced error condition
which gives the designer more system diagnostic capability. The SN74BCT29854 provides inverting logic.
The SN74BCT29854 is characterized for operation from 0°C to 70°C.