The CRITTER System -- Automated Critiquing of Digital Circuit Designs

CRITTER is an exploratory prototype design aid, built using Artificial Intelligence ("Expert Systems") technology, to aid in "critiquing" digital circuit designs, encompassing issues of functional correctness, operating speed, timing robustness, and circuit sensitivity to changes in device parameters. Its non-procedural representation for both real-time circuit behavior and circuit specifications has led to a streamlined circuit modeling formalism based on ordinary mathematical function composition. In its interactions with the user it strives to be as concise as possible, concentrating only on findings it judges to be unexpected or unusual. After successful tests with circuits of up to a dozen TTL SSI/MSI packages, CRITTER is being extended for use in an automated VLSI design environment.