Critic: a knowledge-based program for critiquing circuit designs

Critic is a knowledge-based system that looks for errors or `bad design style´ in circuit designs. Critic takes as input a description of a circuit and a knowledge-base that describes a particular design-style and technology. The knowledge base consists of: process and design-style constants, a set of primitive descriptions, a set of structure descriptions, and error-checking rules. Critic uses the information in the knowledge base to find structures and errors in the circuit. The errors can range from easily recognizable errors such as a transistor bulk being connected to the wrong supply or a static gate having nonequal rise and fall times to hard-to-recognize errors, such as those dealing with charge sharing, timing, and testability. Critic is integrated with the Berkeley CAD system, has an interactive graphical input and feedback, is easy to use, and has a firm separation between the knowledge-base and program internals