Statistical fault sampling

Computational requirements often discourage, or even prohibit, complete fault simulation of circuit designs having greater than 20000 single stuck-at faults. To circumvent this problem, statistical sampling methods have been proposed that provide fault coverage values within a small, predictable error range by simulating only a fraction of the circuit´s total faults and using the result fault coverage value as an estimate of the fault coverage for the total circuit. As an introduction to the application of sampling methods to fault simulation of integrated circuits, the statistical theory behind these sampling methods and proposed augmentations of these methods for improving the precision of the sample fault coverage are presented. Various proposed sampling schemes are applied to example circuit designs, and the results are analyzed