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 () output will
indicate whether or not an error in the B data has occurred. The
output-enable (, ) 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 () flag. can
be either passed, sampled, stored, or cleared from the latch using
the latch-enable () and clear
() control
inputs. When both and 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.