Doctoral Dissertations


"Many well-known synthesis procedures for asynchronous sequential circuits produce minimal or near-minimal results, but are practical only for very small problems. These algorithms become unwieldy when applied to "large" circuits with, for example, three or more input variables and twenty or more internal states. New heuristic procedures are described which permit the synthesis of very large machines. Although the resulting designs are generally not minimal, the heuristics are able to produce near-minimal solutions orders of magnitude more rapidly than the minimal algorithms. A method for specifying sequential circuit behavior is presented. Input-output sequences define submachines or modules. When properly interconnected, these modules form the required sequential circuit. It is shown that the waveform and interconnection specifications may easily be translated into flow table form. A large flow table simplification heuristic is developed. The algorithm may be applied to tables having hundreds of rows, and handles both normal and non-normal mode circuit specifications. Nonstandard state assignment procedures for normal, fundamental mode asynchronous sequential circuits are examined. An algorithm for rapidly generating large flow table internal state assignments is proposed. The algorithms described have been programmed in PL/1 and incorporated into an automated design system for asynchronous circuits; the system also includes minimum and near-minimum variable state assignment generators, a code evaluation routine, a design equation generator, and two Boolean equation simplification procedures. Large sequential circuits designed using the system illustrate the utility of the heuristic procedures"--Abstract, pages ii-iii.


Tracey, James H.

Committee Member(s)

Alcorn, Herbert R., 1933-2008
Kern, Frank J.
Ho, C. Y. (Chung You), 1933-1988
Szygenda, Stephen A.


Electrical and Computer Engineering

Degree Name

Ph. D. in Electrical Engineering


National Science Foundation (U.S.)


University of Missouri--Rolla

Publication Date



ix, 79 pages

Note about bibliography

Includes bibliographical references (pages 77-78).


© 1970 Robert Judson Smith, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Subject Headings

Asynchronous circuits
Sequential circuits
Heuristic programming
Heuristic algorithms

Thesis Number

T 2369

Print OCLC #


Electronic OCLC #