Unformatted text preview: What about the Boolean expression for this circuit? Since the circuit produces two distinct output values, we represent it using two Boolean expressions: sum = A ⊕ B carry = AB Note that a half adder does not take into account a possible carry value into the calculation (carryin). That is, a half adder is fine for adding two single digits, but it cannot be used as is to compute the sum of two binary values with multiple digits each. A circuit called a full adder takes the carryin value into account. We can use two half adders to make a full adder. How? Well, the input to the sum must be the carryin and the sum from adding the two input Sum Carry A B A 1 1 B 1 1 Sum 1 1 Carry 1...
View
Full Document
 Fall '10
 MARIANAKANT
 Addition

Click to edit the document details