Carry lookahead logic is implemented to make the binary adder more efficient.Instead of waiting for the carry to propagate from C0 to Cn in a n-bit adder, this method computes them all simultaneously.The downside is that the hardware complexity increases.
(Carry look ahead is implemented by the 3 AND and 3 OR gates in the center of the circuit, obviously for this 2-bit adder).
About the circuit:
•The 2-bit numbers to be added, from top to Bottom:
B1
B0
A1
A0
•The top Led is C2
mid led is S1
bottom led S0
The logic switch at the bottom is C0 the initial carry.
C: carry , S:Sum
