Universal Gate – NAND NOR Gate Implementation

This Tutorial will demonstrate

  • The basic function of the NAND gate.
  • How a NAND gate can be used to replace an AND gate, an OR gate, or an INVERTER gate.
  • How a logic circuit implemented with AOI logic gates can be re-implemented using only NAND gates.
  • In this case, NAND will reduce the number of integrated circuits (IC) required to implement a logic circuit using a single gate type.

Process for NAND Implementation

  1. If starting from a logic expression, implement the design with AOI logic.

2. Identify and replace every AND, OR, and INVERTER gate with its NAND equivalent in the AOI implementation.

3. Redraw the circuit.

4. Identify and eliminate double inversions (i.e., back-to-back inverters).

5. Redraw the final circuit.