EX-NOR Gate
EX-NOR Gate stands for Exclusive-NOR Gate. It is a combination of EX-OR Gate and NOT Gate. The output of the EX-NOR Gate goes high when the input terminals have the same logic level, it can either be 0 or 1, and the output will still be 1. EX-NOR Gate is sometimes referred to as Equivalence Gate.
2-input EX-NOR Gate
The truth table for a two-input EX-NOR Gate is as follows:
| B | A | Q |
| 0 | 0 | 1 |
| 0 | 1 | 0 |
| 1 | 0 | 0 |
| 1 | 1 | 1 |
When A and B are the same, it gives the output Q.
Boolean Expression= Q=AB+AB
3-input EX-NOR Gate
The truth table for the three-input EX-NOR Gate is as follows:
| C | B | A | Q |
| 0 | 0 | 0 | 1 |
| 0 | 0 | 1 | 0 |
| 0 | 1 | 0 | 0 |
| 0 | 1 | 1 | 1 |
| 1 | 0 | 0 | 0 |
| 1 | 0 | 1 | 1 |
| 1 | 1 | 0 | 1 |
| 1 | 1 | 1 | 0 |
Even the number of inputs gives Q.
Boolean expression=Q = ABC + ABC + ABC + ABC
Reference