A VLSI DESIGN ENVIRONMENT BASED ON A RELATIONAL DATABASE (COMPUTER AIDED DESIGN)

With the increase in size and complexity of VLSI circuits, the amount of data required for the design of a single chip has become unmanageable. Design tools in the past have been developed in an ad hoc manner each with their own specialized data requqirements. One approach to creating a manageable design environment is to provide a central VLSI design data base where all data is stored. Such an approach has an added advantage of facilitating the coordination of the efforts of different designers.;A subset of this environment was implemented using the INGRES database system and the University of California at Berkeley and University of Washington VLSI design tools. This environment was tested with five sample designs to determine its functionality. Performance statistics are given for these five designs.;In evaluating the VLSI design environment two features were found particularly useful: its ability to recognize different representations of equivalent designs and its notification strategies for insuring that designers are aware of changes which affect them. The ability to recognize different representations of equivalent designs can allow for automatic consistency checking thus reducing errors made in translating a design from one representation to another. A set of primitives and their associated algorithms developed to support the notification strategies are independent of the environment presented here and are applicable in other VLSI design environments. Further advantages and limitations of the environment are also presented along with suggestions for further research.;The research reported in this paper discusses the design of an integrated VLSI support environment based on the relational model database. The environment designed addresses five primary areas of concern: recognitiion of equivalence between multiple representations of circuits, coordination of multiple designers, handling of extended design sessions, control of multiple versions and alternatives, and notification to interested designers of changes to circuits. This environment was designed to be based on a commercial database system and to allow for the interfacing of existing VLSI design tools without modification to the tools or the underlying database system.