The 'ABT16833 consist of two noninverting 8-bit to 9-bit parity
bus transceivers and are designed for communication between data
buses. For each transceiver, when data is transmitted from the A bus
to the B bus, an odd-parity bit is generated and output on the parity
I/O pin (1PARITY or 2PARITY). When data is transmitted from the B bus
to the A bus, 1PARITY (or 2PARITY) is configured as an input and
combined with the B-input data to generate an active-low error flag
if odd parity is not detected.
The error (1 or 2) output is configured as an
open-collector output. The B-to-A parity-error flag is clocked into
1 (or 2) on the low-to-high transition of
the clock (1CLK or 2CLK) input. 1 (or 2) is
cleared (set high) by taking the clear (1 or 2) input low.
The output-enable (
and) inputs can be
used to disable the device so that the buses are effectively
isolated. 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 that gives the
designer more system diagnostic capability.
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
driver.
The SN54ABT16833 is characterized for operation over the full
military temperature range of -55°C to 125°C. The
SN74ABT16833 is characterized for operation from -40°C to
85°C.