An error-locating signature analyzer to identify faulty units in digital systems

In conventional signature analysis, faulty units are identified by mismatch between the actual and reference signatures. The amount of reference signatures can be quite large for a complex system that requires high testing resolution. This complicates the diagnosis procedure. We show how under certain restrictions this amount can be reduced, preserving the diagnosis resolution and the aliasing rate. We construct a signature analyzer that is capable of locating faulty units. If the analyzer is implemented in the external automated test equipment, its throughput requirements can be diminished.