Substractors

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 Subtractors

 

Full Subtractor

It used to subtraction among 3 bits

Truth Table

Inputs

Outputs

 A

 BBin D

Bout

0

000

0

0

0111
0101

1

0110

1

1

0010
1010

0

1

1000

1

111

1

A' and' B' are the input variables. 

These variables represent the two significant bits that are going to be subtracted.
 
The third input is 'Bin'  it represents borrow.

The 'D' and 'Bout' are the output variables that define the output values.

The eight rows under the input variable designate all possible combinations of 0 and 1 which will occur in these variables.

D = A’B’ Bin + AB’ Bin’+ A’B Bin’ + AB Bin

Bout = A’ Bin + A’B + B Bin

Create Circuit & Simulate

Select Subtractor & get it

Then change number of bits

connect wires & Inputs, outputs

Simulate



Half Subtractor

The half subtractor is additionally a building block for subtracting two binary numbers. it's two inputs and two outputs. This circuit is employed to subtract two single bit binary numbers A and B. The 'diff' and 'borrow' are two output states of the half subtractor.


 


Truth Table

A

B

D

Bout

0

0

0

0

0

1

1

1

1

0

1

0

1

1

0

0


'A' and 'B' are the input variables whose values are getting to be subtracted.
The 'Diff' and 'Borrow' are the variables whose values define the subtraction result, i.e., difference and borrow.
The first two rows and therefore the last row, the difference is 1, but the 'Borrow' variable is 0.
The third row is different from the remaining one. once we subtract the bit 1 from the bit 0, the borrow bit is produced.

How to create a Circuit & Simulate

 Select Logic Gates and get them

change their number of inputs

connect wires inputs and outputs carefully

after Simulate the Circuit

  








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