As integrated circuit (IC) complexities increase, many existing computer-aided design (CAD) methods must be replaced with an integrated design system to support very large scale integrated (VLSI) circuit and system design. The framework for a hierarchical CAD system is described. The system supports both functional and physical design from initial specification and system synthesis to simulation, mask layout, verification, and documentation. The system is being implemented in phases on a DECSystem 20 computer network and will support evolutionary changes as new technologies are developed and design strategies defined.

Substantial progress was made in implementing design aids during the 1970s; however, the development of new aids must be accelerated during the 1980s to support circuit designs of VLSI complexity. New design aids-will be required because of (1) increased design complexity, (2) scarcity of design engineers, (3) need to reduce circuit design time and cost, and (4) increased emphasis in producing error-free manufacturable designs. The reduction of fabrication costs will become more important as processing equipment costs and the sophistication of individual processing steps continues to increase to support VLSI complexity circuits. These design and manufacturing problems can be solved only by increasing the use of design automation and improving the design aids.

A Circuit MAsk Translator (CMAT) code has been developed which converts integrated circuit mask information into a circuit schematic. Logical operations, pattern recognition, and special functions are used to identify and interconnect diodes, transistors, capacitors, and resistances. The circuit topology provided by the translator is compatible with the input required for a circuit analysis program.