Low power carry lookahead adder by using dependency between generation and propagation

Abstract

The adder is the most important and basic circuit component in the computer arithmetic area. Among the various kinds of adders, the CLA (Carry Lookahead Adder) is generally considered the fastest and most complex adder. The complexity is closely related to power consumption, and a more complex one may require more power consumption. In this paper, we explore the relationship between the generation signal and the propagation signal of the CLA, and we present a low power consumption CLA by taking advantage of the conditional don't care that exists in the generation and propagation signals. Our results show that this proposed CLA can reduce switching activity by 9-11% comparing to a conventional CLA.