Shift Registers

A Flip flops can be used to store a single bit of binary data (1or 0). However in order to store multiple bits of data we need multiple flip flops. N flip flops are to be connected in an order to store n bits of data. A Register is a device which is used to store such information. It is a group of flip flops connected in series used to store multiple bits of data.

The information stored within these registers can be transferred with the help of shift registers. Shift Register is a group of flip flops used to store multiple bits of data. The bits stored in such registers can be made to move within the registers and in/out of the registers by applying clock pulses. An n-bit shift register can be formed by connecting n flip-flops where each flip flop stores a single bit of data.

The registers which will shift the bits to left are called “Shift left registers”.
The registers which will shift the bits to right are called “Shift right registers”.

Shift registers are basically of 4 types. These are:

  1. Serial In Serial Out shift register
  2. Serial In parallel Out shift register
  3. Parallel In Serial Out shift register
  4. Parallel In parallel Out shift register