These octal D-type edge-triggered flip-flops feature inverting 3-state outputs designed specifically for bus driving. They are particularly suitable for implementing buffer registers, I/O ports, bidirectional bus drivers, and working registers. The eight flip-flops enter data on the low-to-high transition of the clock (CLK) input. The output-enable () input does not affect internal operations of the flip-flops. Old data can be retained or new data can be entered while the outputs are in the high-impedance state. The SN54ALS564B is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ALS564B is characterized for operation from 0°C to 70°C.