Low-Power Diagnostic Test Sets for Transition Faults Based on Functional Broadside Tests

Functional broadside tests address overtesting due to high-power dissipation by creating functional operation conditions during the clock cycles where delay faults are detected. Guided by their switching activity, it is possible to generate a low-power test set whose switching activity does not exceed the switching activity possible during functional operation. This brief applies the same approach to the generation of a low-power diagnostic test set. Excessively high switching activity can cause unexpected fault effects to appear, which will reduce the accuracy of fault diagnosis. This is avoided with a low-power diagnostic test set. Functional broadside tests are also used for avoiding diagnostic tests with unnecessarily low switching activity. The procedure described in this brief is the first to generate low-power diagnostic tests under functional constraints on switching activity as given by functional broadside tests.