Texas Instruments SN54LS91

these monolithic serial-in serial-out 8-bit shift registers utilize transistor-transistor logic (ttl) circuits and are composed of eight r-s master-slave flip-flops input gating and a clock driver. single-rail data and input control are gated through inputs a and b and an interanl inverter to form the complementary inputs to the first bit of the shift register. drive for the internal common clock line is provided by an inverting clock driver. this clock pulse inverter/driver causes these circuits to shift information one bit on the positive edge of an input clock pulse.