A Symbolic Design System for Integrated Circuits

As integrated circuit design has become increasingly complex, the need for more effective data description techniques has become critical. Design verification from mask artwork data alone can consume vaste amounts of computer time for VLSI circuits, if it can be performed at all. The use of a symbolic design description, which allows the designer or synthesis program to express circuit structure as well as maintain full connectivity information, can reduce dramatically the burden placed on the verification tools. This paper describes a symbolic design system, its associated data manager, its color graphics viewport manager, and its application to a variety of design methods. The data manager can store a variety of representations of the design, including simulation data, geometric layout, symbolic layout, and schematic diagrams. The viewport manager can manage a number of viewports concurrently and the use of a model frame buffer allows it to function easily on a variety of graphics terminals and hard-copy devices. The system is designed with an engineering work station in mind.