Half Adder
The addition of 2 bits is done using a combination circuit called a Half adder. The input variables are augend and addend bits and output variables are sum & carry bits. A and B are the two input bits. Truth Table:
 Truth Table:

Here we perform two operations Sum and Carry, thus we need two K-maps one for each to derive the expression.
Logical Expression:
1) for Sum:

Sum = A XOR B
2) for Carry:

Carry = A AND B
Implementation:

Note:
Half adder has only two inputs and there is no provision to add a carry coming from the lower order bits when multi addition is performed.
 
Comments
Post a Comment