A shift register is a sequential logic circuit that acts as a unit to store and transfer binary data. Basically shift registers are bidirectional FIFO circuit, that shifts every single bit of the data present in its input towards its output on each clock pulse.
Basically, these registers are classified into four types and working of shift registers are discussed below.
Serial in Serial out (SISO) Shift Register
Serial in parallel out (SIPO) Shift Register
Parallel in Serial out (PISO) Shift Register
Parallel in Parallel out (PIPO) Shift Register
we will discuss this about each types of register in next chapters.