Prerequisite : Full Subtractor
Given three inputs of Full Subtractor A, B, Bin. The task is to implement the Full Subtractor circuit and Print output states difference (D) and Bout of three inputs.
Introduction :
The full subtractor is used to subtract three 1-bit numbers which are minuend, subtrahend, and borrow, respectively. The full subtractor has three input states and two output states. The two outputs are difference and borrow.
Here we have three inputs A, B, Bin and two outputs D, Bout. And the truth table for full subtractor is
Logical Expression :
Difference = (A XOR B) XOR Bin Borrow Out = Ā Bin + Ā B + B Bin
Examples –
Input : 0 0 1
Output : Difference=1, B-Out=1
Explanation : According to logical expression Difference= (A XOR B) XOR Bin i.e (0 XOR 0) XOR 1 =1 ,
B-Out=Ā Bin + Ā B + B Bin i.e. 1AND 1 + 1 AND 0 + 0 AND 1 = 1.
Input : 1 0 1
Output : Difference=0, B-Out=0
Approach :
- We will take three inputs A, B, Bin.
- By applying (A XOR B) XOR Bin gives the Value of Difference.
- By applying Ā Bin + Ā B + B Bin gives the value of B-Out.
//c++ code for above approach #include <bits/stdc++.h> using namespace std;
//function to print difference and borrow out void Full_Subtractor( int A, int B, int Bin){
// Calculating value of Difference
int Difference = (A ^ B) ^ Bin;
//calculating NOT value of a
int A1 = not(A);
//Calculating value of B-Out
int B_Out = A1 & Bin | A1 & B | B & Bin;
//printing the values
cout<< "Difference = " <<Difference<<endl;
cout<< "B-Out = " <<B_Out<<endl;
}
//Driver code int main() {
int A = 1;
int B = 0;
int Bin = 1;
// calling the function
Full_Subtractor(A, B, Bin);
return 0;
} |
Difference = 0 B-Out = 0