In digital circuits, a shift register is a cascade of flip-flops, sharing the same clock, in which the output of each flip-flop is connected to the "data" input of the next flip-flop in the chain.

Serial-in, parallel-out (SIPO):

This configuration allows conversion from serial to parallel format. Data is input serially. Once the data has been clocked in, it may be either read off at each output simultaneously, or it can be shifted out and replaced.

In cases where the parallel outputs should not change during the serial loading process, it is desirable to use a latched or buffer register. In a latched shift register (such as the 74595) the serial data is first loaded into an internal buffer register, then upon receipt of a load signal the state of the buffer register is copied into a set of output registers. In general, the practical application of the serial-in/parallel-out shift register is to convert data from serial format on a single wire to parallel format on multiple wires.

APPLICATION:

The practical application of the serial-in/parallel-out shift register is to convert data from serial format on a single wire to parallel format on multiple wires. Perhaps, we will illuminate four LEDs (Light Emitting Diodes) with the four outputs (QA QB QCQD).