Introduction

Abstract

It has now been over a quarter century since the computer was introduced as an important tool in the design of integrated circuits (IC’s) and systems and over the past decade it has become indispensable. Along with the rapid growth in the complexity of integrated circuits and digital systems has come an even more rapid growth in the complexity of the software tools and associated data needed to represent a design. A typical Computer-Aided Design (CAD) or Computer-Aided Engineering (CAE) system today consists of over one million lines of source code and many CAD systems contain over ten million lines of code. The data needed to describe a state-of-the-art integrated circuit, representing about 500,000 equivalent logic gates or a million transistors, can exceed two gigabytes. While the CAD tools themselves are essential to the design process, the management of such vast amounts of data and its presentation, in a useful and efficient form, to CAD programs, to designers, and to manufacturing equipment alike, has become a major issue in the electronics industry.