This is a collaborative effort between Professors M. Karpovsky at BostonUniversity and D. Pradhan at the University of Massachusetts. The proposedinvestigations are two.fold. The first concerns fault detection by acompression of test responses. Errors (manifestations of faults) are definedas the component.wise exclusive OR between actual test responses and fault.free responses. Faults are masked if the observed signature (compressed test response) is equal to the reference. Thus, depending on the statistics of theerrors, an optimal compressor is the compressor that minimizes a probabilitythat the test responses are compressed into the reference. The design ofoptimal compressors when the distribution of ones contained in error sequences is known for a given circuit under test is being investigated. This work isalso based on single error correcting codes over a finite field. Second isboard . level diagnosis by signature analysis. The objective is to analyzetradeoffs between the hardware complexity of the redundant chips on the boardand test time. Two techniques, based on compression of test responses, arebeing pursued. These are; space . time compression of test responses, anextension of previous research in space compressors; and board diagnosis byHamming codes over a finite field. Professors Karpovsky and Pradhan, are outstanding researchers with solidrecords of accomplishment over the past decade, and that they are very likelyto continue first class research. The research topic, test response analysis, is important to industry, and is a high.priority category within the Design,Tools and Test Program.
