EXNOR gate means exclusive NOR gate and is a combination of X-OR and NOT gate. It also has two inputs and one output. When both the inputs are at 0, the output of the EXNOR gate will be high i.e.1. If one of the input is 0 and the other is 1 the output will be 0, and the gate is known as Coincidence gate.
The logical symbol of the gate is shown below:
It is also called an inequality detector. The output of the exclusive ex-nor gate is high only when both the inputs of the gate are at the same logic (i.e, both the inputs are either high or low). The output of the gate is high only when both of their inputs are equivalent to each other and because of this the ex-nor gate is known as an equivalent gate.
The logical symbol of exclusive nor gate is represented by the exclusive-or gate with the bubble. It is complementary to the exclusive or gate.
The truth table of the gate is given below:
| A | B | Z |
|---|---|---|
| 0 | 0 | 1 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |
In general, the output of the logic gate is high only when its inputs are of even numbers and low output is obtained only when its inputs are of odd numbers.