NOR logic
From Wikipedia, the free encyclopedia
Like NAND gates, NOR gates can be combined to form any other kind of logic gate.
Contents |
[edit] NOT
This is made by joining the legs of a NOR gate. This is because A and B are always equal, and the NOR will act as an inverter.
| Desired Gate | NOR Construction |
 |
 |
[edit] OR
An OR gate is an inverted NOR gate.
| Desired Gate | NOR Construction |
 |
 |
[edit] AND
Made by connecting two NOT gates to a NOR gate.
| Desired Gate | NOR Construction |
 |
 |
[edit] NAND
A NAND gate combines an AND gate and a NOT gate.
| Desired Gate | NOR Construction |
 |
 |
[edit] XOR
An XOR gate is a combined AND gate and NOR gate, of which both outputs are connected to a NOR gate
| Desired Gate | NOR Construction |
 |
 |
[edit] XNOR
An XNOR gate is simply an XOR gate with an inverted output:
| Desired Gate | NOR Construction |
 |
 |
Alternately, an XNOR gate can be constructed using only four NOR gates as follows. Call the two inputs A and B. The first NOR gate is connected to A and B. The second NOR gate is connected to A and the output of the first NOR gate. The third NOR gate is connected to B and the output of the first NOR gate. The fourth NOR gate is connected to the outputs of the second and third NOR gates.
