Buffer Insertion for Delay Minimization using An Improved PSO Algorithm

This paper considers the problem of interconnect wire delay in digital integrated circuits. The correct wire sizing and buffer insertion/sizing can reduce the interconnect delay. The interconnect wire is divided into segments and to optionally buffers are inserted between two adjacent segments. But it is important to select appropriate values for the size of buffers as well as the lengths and widths of segments to minimize the delay. Since the delay is a multi-dimensional function, its optimizing process is complex and time-consuming. In this paper we introduce an improved particle swarm optimization for delay minimization. The aim is to reduce the interconnect wire delay. This work is performed in 3 case studies. Sizing a chain of buffers without considering the wire delay is done in case study 1. Wire sizing alone and buffer insertion/sizing with wire sizing are dealt in case study 2 and case study 3 respectively. In these case studies, the our improved PSO results are matched with theoretical results while the proposed technique is very fast and more accurate than standard techniques.