In which of the following adder circuits, the carry look ripple delay is eliminated?
carry look ripple delay is eliminated in Carry-look-ahead adder as carry is already provided before the operation starts .
carry is calculated as follows:-
Substituting C1 into C2, then C2 into C3, then C3 into C4 yields the following expanded equations:
Here G (carry generator) is equal to
P(propagate) as follows
all the carry are calculated using the above formula and provided to input as mentioned in a diagram. Thus ripple delay is eliminated.
follow this link for further clarification:- https://www.geeksforgeeks.org/carry-look-ahead-adder/
Option D; as in CLA the carry is generated in parallel. Hence no concept of ripple carry.