Description
This bidirectional shift register is designed to incorporate virtually all of the features a system designer may want in a shift register it features parallel inputs parallel outputs right-shift and left-shift serial inputs operating-mode-control inputs and a direct overriding clear line The register has four distinct modes of operation namely Parallel (broadside) load Shift right (in the direction QA toward QD) Shift left (in the direction QD toward QA) Inhibit clock (do nothing) Synchronous parallel loading is acplished by applying the four bits of data and taking both mode control inputs S0 and S1 high The data is loaded into the associated flipflops and appears at the outputs after the positive transition of the clock input During loading serial data flow is inhibited Shift right is acplished synchronously with the rising edge of the clock pulse when S0 is high and S1 is low Serial data for this mode is entered at the shift-right data input When S0 is low and S1 is high data shifts left synchronously and new data is entered at the shift-left serial input Clocking of the flip-flop is inhibited when both mode control inputs are low The mode controls of the DM54194 DM74194 should be changed only while the clock input is high.
