Maximizing the fault coverage in complex circuits by minimal number of signatures

Abstract

Methods to minimize the number of evaluated signatures without reducing the fault coverage are presented. This is possible because the signatures can influence one another during the test execution. For a fixed test schedule a minimal subset of signatures can be selected, and for a predetermined minimal subset of signatures the test schedule can be constructed such that the fault coverage is maximum. Both approaches result in significant hardware savings when a self-test is implemented.