Design and Implementation of an Efficient Hybrid Parallel-Prefix Ling Adder Using 0.18micron CMOS Technology in Standard Cell Library

Abstract

This This paper addresses a novel technique in implementing hybrid parallel-prefix adder (HPA) incorporating prefix-tree structure with Carry Select Adder (CSEA). Ling’s algorithm is used to optimise the pre-processing blocks (white nodes) and intermediate Generate-Propagate blocks (Black nodes) of the prefix tree to minimise the congestion of wires which contributes to reduction in chip size and to improve performance. The resulting prefix-tree arrangement is then merged into a sequence of modified CSEA. Experimental results show that HPA has speed improvement of 62% and 13% power reduction in comparison of the traditional Carry Look-Ahead Adder (CLA).