Hazard Detection in Combinational and Sequential Switching Circuits

E. B. Eichelberger

IBM Journal of Research and Development · 1965 · 287 citations · 6 references

Concepts

TL;DR

Hazards arise in combinational networks from simultaneous input changes and in gate‑type sequential circuits from race conditions that can lead to incorrect terminal states. The study proposes a technique to detect hazards caused by single‑ and multiple‑input changes in circuits. The method, implementable as a computer program, can detect any hazard or race condition in circuits with hundreds of logic blocks.

Abstract

This paper is concerned with a unified approach to the detection of hazards in both combinational and sequential circuits through the use of ternary algebra. First, hazards in a combinational network resulting from the simultaneous changing of two or more inputs are discussed. A technique is described that will detect hazards resulting from both single- and multiple-input changes. The various types of hazards connected with gate-type sequential circuits are also discussed, and a general technique is described that will detect any type of hazard or race condition that could result in an incorrect terminal state. This technique could be easily implemented in a computer program which would be capable of detecting hazards in circuits containing hundreds of logic blocks.

References

6