High Speed CMOS Logic 8-Bit Shift Register With Input Storage

The ?HC597 and CD74HCT597 are high-speed silicon Gate CMOS devices that are pin compatible with the LSTTL 597 devices. Each device consists of an 8-flip-flop input Register and an 8-bit parallel-in/serial-in, serial-out Shift register Each Register is controlled by its own Clock A "low" on the parallel load input (PL) shifts parallel stored data asynchronously into the Shift register A "low" master input (MR) clears the Shift register Serial input data CAN also be synchronously shifted through the Shift register when PL is high.
By Texas Instruments