Quality of designs from an automatic logic generator (ALERT)

Abstract

Automation of the design of computer logic has evoked wide-spread interest and activity. Never-theless, detailed comparisons of automatically generated logic and manually prepared logic have not been made available. The ALERT program is a logic generator which accepts as input a summary description of a new computer in a high-level language, and from this it compiles logic designs to carry out the func-tions specified. This paper examines the quality of logic generated by the ALERT system. The specifications of several computers have been processed through the ALERT system. This report discusses the most comprehensive design processed, the central processor of the IBM 1800 computer. The 1800 had been designed by conventional man-ual techniques prior to this study, and its logic schematics were, therefore, available for compar-ison with the logic generated by ALERT. It was found that the automatically produced circuitry required 160% more components than used in the corresponding parts of the actual computer. Reasons for this discrepancy are considered, and methods are described which are expected to re-duce the discrepancy between automatically gener-ated designs and manual designs. The study indicates that automatic generation of computer logic and circuitry from high-level system descriptions offers a practical and viable alternative to traditional methods of logic de-sign. Within the limits of the study, the auto-matically prepared design was found to be correct, functional, and manufacturable.