The TC74HC597A is a high speed CMOS 8-BIT PARALLEL-IN/SERIAL-IN SERIAL-OUT LATCH/SHIFT REGISTER fabricated with silicon gate C2MOS technology. It achieves the high speed operation similar to equivalent LSTTL while maintaining the CMOS low power dissipation. It consists of an 8-bit data register feeding an 8-bit shift register. The parallel data on the A to H inputs is stored in the input register on the positive going transition of RCK. When the SLOAD input is held low, the input register data is passed into the shift registers. When SLOAD input is held high, the serial data input (SI) is enabled and the eight flip-flops perform serial shifting on the positive transition of SCK. A direct clear input ( SCLR ) sets the 8-bit shift register to zero. All inputs are equipped with protection circuits against static discharge or transient excess voltage.