The Manchester carry scheme is a particularly elegant approach to dealing with CLA bits. It is based on building a switch-logic network for the basic equation,

that can be cascaded to feed to successive stages.

Consider a full adder with inputs ai, bi, and ci. We will use the generate and propogate expression

to introduce the carry-kill bit ki such that

This term gets its name from the fact that if ki=1, then pi=0 and gi=0, so that ci+1=0;ki=1 thus kills the carry-out bit. It can be verified from the table as shown

Manchester carry circuit using carry kill signal.

4-input dynamic Manchester carry chain circuit.