The EXCLUSIVE NOR gate gives an output of 1 when both inputs are equal – both 0 or both 1. The symbol is shown below.
The truth table for the XNOR gate is shown below.
|
A |
B |
Output |
|
0 |
0 |
1 |
|
1 |
0 |
0 |
|
0 |
1 |
0 |
|
1 |
1 |
1 |
The EXCLUSIVE NOR gate may be constructed from two NOT gates, two AND gates and an OR gate as shown below. The Boolean expression for the output is
