2V-to-5.5V, 8-bit parallel-out serial shift register

The SN74AHC164 is an 8-bit shift

register with AND-gated serial inputs and an asynchronous clear (CLR)

input. Outputs are directly connected to the internal shift register, resulting in immediate

output changes as values are shifted into the register. The gated serial (A and B) inputs

permit complete control over incoming data; a low at either input inhibits entry of the new

data and resets the first flip-flop to the low level at the next clock (CLK) pulse. A

high-level input enables the other input, which then determines the state of the first

flip-flop. Data at the serial inputs can be changed while CLK is high or low, provided the

minimum set-up time requirements are met. Clocking occurs on the low-to-high-level

transition of CLK.