Date: 27 Apr 2015

Shift register is an array of flip-flops capable of shifting the binary information from any cell to its neighboring cell. It can shift information either to the left or to the right.

A typical shift register has a chain of flip-flops in cascade. The output of a flip-flop is
connected to the input of the next flip-flop. A common clock pulse activates the shift of data from one stage to the next.

Shifting of bits is essential for doing some arithmetic and logic operations used in
microcomputers.

Types of shift registers

There are two main types of shift registers: right-shift register and left-shift register. These categories are further divided into four categories.

1. Serial-in, serial-out
2. Serial-in, parallel-out
3. Parallel-in, parallel-out
4. Parallel-in, serial-out