1. Half & Full Subtractor
Half Subtractor
Full Subtractor

2. Half- Subtractor
Function Table
Expression
Logic Circuit

3. Half- Subtractor Function Table
Input
Output A B
Difference
Borrow 1

4. Half- Subtractor Circuit

5. Full- Subtractor
Function Table
Expression
Logic Circuit

6. Full-Subtractor Function Table
Input
Output A B C
Difference
Borrow 1

7. Difference Expression

8. Borrow Expression
A’B’
A’B AB 1 C’ C

9. Full-Subtractor Circuit
-Draw the circuit

10. Full-Subtractor based on Two Half-Subtractors
Full-Subtractor = Half-Subtractor + Half-Subtractor

11. Parallel Binary Subtractor
Multiple Single bit Full-Subtractr connected in Parallel

12. 4-bit Parallel Subtractor

13. Binary Adder and Subtractor
A complete logical circuit capable of adding or subtracting two numbers by using 2’s complement is shown in Figure below