# N-Bit Parallel Subtractor

Posted By on September 30, 2014

## N-Bit Parallel Subtractor

The subtraction can be carried out by taking the 1’s or 2’s complement of the number to be subtracted. For example we can perform the subtraction (A-B) by adding either 1’s or 2’s complement of B to A. That means we can use a binary adder to perform the binary subtraction.

### 4 Bit Parallel Subtractor

The number to be subtracted (B) is first passed through inverters to obtain its 1’s complement. The 4-bit adder then adds A and 2’s complement of B to produce the subtraction. S3 S2 S1 S0 represent the result of binary subtraction (A-B) and carry output Cout represents the polarity of the result. If A > B then Cout =0 and the result of binary form (A-B) then Cout = 1 and the result is in the 2’s complement form.

### Block diagram

#### Posted by Akash Kurup

Founder and C.E.O, World4Engineers Educationist and Entrepreneur by passion. Orator and blogger by hobby

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