Carry-lookahead adder
An approach in-between our two extremes
Motivation:
- If we didn't know the value of carry-in, what could we do?
- When would we always generate a carry? gi = ai bi
- When would we propagate the carry? pi = ai + bi
Did we get rid of the ripple?
c4 = g3 + p3c3 c4 = Feasible! Why?