Low power self-timed carry lookahead adders

Cell based self-timed synthesis of recursive carry lookahead adders (RCLA) utilizing generate, propagate and kill functions is described in this paper, and are compared with the recently proposed designs of self-timed section-carry based carry lookahead (SCBCLA) adders. From the simulation results corresponding to a 130nm CMOS process, it is found that with 2-bit CLA, the RCLA adder dissipates 20.2% less power than the SCBCLA adder. With 4-bit CLA, the RCLA adder reports power reduction by 16.5% than the SCBCLA adder. Further, for addition widths ranging from 32 to 64-bits, RCLA adders consume 19% less average power compared to SCBCLA adders.