# What is shift register?, types of a shift register.

Hello friends, in this article I am going to tell you what is shift register? types of a shift register. so let’s start

## What is Shift Register?

When the input is applied serially, i.e. when data is given one by one bit on a single input line, it is in serial and when output is also taken in serial, it is serial in serial out, shift register. types of a shift register. SISO shift registers can be of two types…
(a) Left Shift Register
(b) Right Shift Register

Data can be shifted right to left (from LSB to MSB) in the left shift register and data can be shifted left to right (MSB to LSB) in the right shift register.

(a) Left Shift Register-Right is given to the serial input on most flip-flops. The data input is either 0 or 1, it is given at the D input of the flip flop A.

A clock pulse is given to all the flip flops simultaneously. As soon as flip-flop A receives the clock pulse, the data on the serial input reaches bit Q and at the same time the data stored on A is shifted to the flip-flop B. Similarly on each clock pulse, the data stored at each stage of the register is shifted one stage to the left.
Initially, all flip-flops are reset so Q3Q2Q1Q0 = 0000 Now with clock pulse let’s input ‘1’ to flip-flop A this ‘1’ shifts to the next flip-flop and registers after four clock pulses The stage will be 1111.
The truth table of the Shin left register when all the flip-flops are RESET

(b) Right Shift Register – This is exactly the opposite of the left shift register. The data input is given from left to i.e., first flip-flop A. On receiving the clock pulse, the data input shifts from MSB to LSB. If all flip-flop A gets input ‘1’ then output Q.’ Will happen. Upon receiving a clock pulse, this ‘1’ will be shifted to the next flip-flop B and on each clock pulse, the data will shift from MSB to LSB.

Now you must have known what is shift register? and types of shift registers.