The PI74ALVCH16821 is a 20-bit bus interface flip-flop designed for 2.3V to 3.3V VCC operation. It can be used as two 10-bit flipflops or one 20-bit flip-flops. The 20 flip-flops are edge-triggered D-type flip-flops. On the positive transition of the clock (CLK) input, the device provides true data at the Q outputs. A buffered output-enable (OE) input can be used to place the ten outputs in either a normal logic state (HIGH or LOW level) or a high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. The highimpedance state and increased drive provide the capacity to drive bus lines without the need for interface or pullup components. OE does not affect the internal operation of the flip-flops. Old data can be retained or new data can be entered while the outputs are in the high-impedance state.