9-Bit Parity Generators/Checkers With Bus Driver Parity I/O Ports

The 74ACT11286 universal 9-bit parity generator/checker features a local output for parity checking and a bus-driving parity I/O port for parity generation/checking. The word-length capability is easily expanded by cascading.

The control input is implemented specifically to accommodate cascading. When the is low, the parity tree is disabled and the PARITY ERROR output remains at a high logic level, regardless of the input levels. When is high, the parity tree is enabled. PARITY ERROR indicates a parity error when either an even number of inputs (A through I) are high and PARITY I/O is forced to a low logic level, or when an odd number of inputs are high and PARITY I/O is forced to a high logic level.

The I/O control circuitry is designed so that the I/O port remains in the high-impedance state during power up or power down, to prevent bus glitches.

The 74ACT11286 is characterized for operation from -40°C to 85°C.