Half Subtractor and Full Subtractor using Gates

HALF SUBTRACTOR AND FULL SUBTRACTOR USING GATES

AIM:

To realize the arithmetic circuits half subtractor and full subtractor using,

• NAND and XOR gates
• NAND gates only

MATERIALS AND TOOLS REQUIRED:

IC 7400, 7486, digital training kit, power supply.

THEORY:

The half subtractor is a two input and two output circuit. Input A is the minuend and input B is the subtrahend. The outputs are difference bits and borrow bits. From the truth table, the following equation can be deduced.

            We require a full subtractor circuit for preparing multi bit subtractor where a borrow from a previous bit position may also be there. It has two outputs, the difference D and  borrow Bout.

Circuit Diagram:

PROCEDURE:

Test the ICs using digital IC tester. Set up the circuits of half subtractor and full subtractor using NAND and EXOR gates and verify the truth table

RESULT:

Half subtractor and full subtractor circuits are realized using NAND and XOR gates and the truth tables are verified.