Digital Logic Gates

The XNOR Gate

  1. Another basic logic element is the XNOR gate:

  2. TheStandard Digital Logic symbol for an XNOR gate:

    [xnor1.gif]

  3. An XNOR gate can have 2 or more inputs and a single output.
  4. The XNOR gate output is binary 0 if any one of the inputs are binary 1.
  5. The XNOR gate output is binary 1 when all inputs are binary 0 or 1.
  6. A circle with a plus sign [xor2.gif] is used to signify the logical XNOR function.
  7. The output for the XNOR gate pictured is read as, Y is exclusively NOT A or B.
  8. The Truth Table for the XNOR gate:

    [1ttxnor1.gif]