Hazard Algebras

J. A. Brzozowski
Department of Computer Science
University of Waterloo
Waterloo, Ontario, Canada N2L 3G1
brzozo@uwaterloo.ca

and

Z. Esik
Department of Computer Science
University of Szeged
Szeged, Hungary
esik@inf.u-szeged.hu

July 11, 2000

Abstract

We introduce algebras capable of representing, detecting, identifying, and counting
static and dynamic hazard pulses on any wire in a gate circuit. These algebras also
permit us to count the number of signal changes on any wire. This is of interest to
logic designers for two reasons: each signal change consumes energy, and unnecessary
multiple signal changes slow down the circuit operation. We describe efficient circuit
simulation algorithms based on our algebras and illustrate them by several examples.
Our method generalizes Eichelberger's ternary simulation and several other algebras
designed for hazard detection.