Parallel Prefix Han-Carlson Adder

Abstract

Binary addition is one of the most important arithmetic functions in modern digital VLSI systems. Adders are extensively used as DSP lattice filter where the ripple carry adders are replaced by the parallel prefix adder to decrease the delay. The requirement of the adder is that it is fast and secondly efficient in terms of power consumption and chip area. Parallel prefix adder is a technique for improving the speed of the addition. Parallel prefix adders provide a good theoretical basis to make a wide range of design tradeoffs in terms of area, delay and power. This technique is more suited for adders with wider word lengths. In this paper, a modified Parallel Prefix Han-Carlson Adder is introduced which uses different stages of Brent-Kung and Kogge-Stone adders which reduces the complexity of the adder design.