Texas Instruments

These data selectors/multiplexers contain inverters and drivers to supply full binary decoding data selection to the AND-OR gates. Separate output control inputs are provided for each of the two 4-line sections. The 3-state outputs can interface with and drive data lines of bus-organized systems. With all but one of the common outputs disabled (at a high-impedance state), the low impedance of the single enabled output drives the bus line to a high or low logic level. Each output has its own output-enable () input. The output is disabled whenis high. The SN54ALS253 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ALS253 and SN74AS253A are characterized for operation from 0°C to 70°C. Select inputs A and B are common to both sections. These data selectors/multiplexers contain inverters and drivers to supply full binary decoding data selection to the AND-OR gates. Separate output control inputs are provided for each of the two 4-line sections. The 3-state outputs can interface with and drive data lines of bus-organized systems. With all but one of the common outputs disabled (at a high-impedance state), the low impedance of the single enabled output drives the bus line to a high or low logic level. Each output has its own output-enable () input. The output is disabled whenis high. The SN54ALS253 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ALS253 and SN74AS253A are characterized for operation from 0°C to 70°C. Select inputs A and B are common to both sections.

These data selectors/multiplexers are designed to multiplex signals from 4-bit data sources to 4-output data lines in bus-organized systems. The 3-state outputs do not load the data lines when the output-enable () input is at a high logic level. The SN54ALS257A and SN54ALS258A are characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ALS257A, SN74ALS258A, SN74AS257, and SN74AS258 are characterized for operation from 0°C to 70°C. These data selectors/multiplexers are designed to multiplex signals from 4-bit data sources to 4-output data lines in bus-organized systems. The 3-state outputs do not load the data lines when the output-enable () input is at a high logic level. The SN54ALS257A and SN54ALS258A are characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ALS257A, SN74ALS258A, SN74AS257, and SN74AS258 are characterized for operation from 0°C to 70°C.

The SN54AS286 and SN74AS286 universal 9-bit parity generators/checkers feature a local output for parity checking and a 48-mA bus-drivingparity input/output (I/O) port for parity generation/checking. The word-length capability is easily expanded by cascading. The transmit () control input is implemented specifically to accommodate cascading. Whenis low, the parity tree is disabled and PARITY ERROR remains at a high logic level regardless of the input levels. Whenis high, the parity tree is enabled. PARITY ERROR indicates a parity error when either an even number of inputs (A-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 was designed so that the I/O port remains in the high-impedance state during power up or power down to prevent bus glitches. The SN54AS286 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74AS286 is characterized for operation from 0°C to 70°C. The SN54AS286 and SN74AS286 universal 9-bit parity generators/checkers feature a local output for parity checking and a 48-mA bus-drivingparity input/output (I/O) port for parity generation/checking. The word-length capability is easily expanded by cascading. The transmit () control input is implemented specifically to accommodate cascading. Whenis low, the parity tree is disabled and PARITY ERROR remains at a high logic level regardless of the input levels. Whenis high, the parity tree is enabled. PARITY ERROR indicates a parity error when either an even number of inputs (A-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 was designed so that the I/O port remains in the high-impedance state during power up or power down to prevent bus glitches. The SN54AS286 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74AS286 is characterized for operation from 0°C to 70°C.