Computer Organisation & Architecture

PROGRAM IN MATLAB FOR SUBTRACTION OF TWO UNSIGNED INTEGER BINARY NUMBER (4BITS NUMBERS)


function lab3_coa
a=input('enter a:');
b=input('enter b:');
c=0;
temp=a;
for i=4:-1:1
    if(b(1,i)==1)
        b(1,i)=0;
 
    else
        b(1,i)=1;
    end
end
a=[0 0 0 1];
for i=4:-1:1
sum=xor(xor(a(1,i),b(1,i)),c);
carry=or(and(a(1,i),b(1,i)),and(xor(a(1,i),b(1,i)),c));
c=carry;
result(1,i)=sum;
end
a=temp;
b=result;
c=0;
for i=4:-1:1
sum=xor(xor(a(1,i),b(1,i)),c);
carry=or(and(a(1,i),b(1,i)),and(xor(a(1,i),b(1,i)),c));
c=carry;
result(1,i)=sum;
end
if(c==0)
    fprintf('The number is negative.');
    for i=4:-1:1
    if(result(1,i)==1)
        result(1,i)=0;
 
    else
        result(1,i)=1;
    end
    end
a=[0 0 0 1];
for i=4:-1:1
sum=xor(xor(a(1,i),result(1,i)),c);
carry=or(and(a(1,i),result(1,i)),and(xor(a(1,i),result(1,i)),c));
c=carry;
result(1,i)=sum;
end
end
disp(result);
disp(c);

end