Optimal robust compression of test responses

A compression of test responses technique for a built-in self-test (BIST) VLSI design is presented. The authors introduce the notion of a robust compression technique which incorporates prior knowledge of the statistics of fault-free responses under pseudorandom testing to achieve a guaranteed error detectability independent of a distribution of errors. The presented robust quadratic compressor requires two r-bit registers (r-bit signature) more than a multiple-input linear feedback shift register; however, it provides for equal protection against all error patterns. Therefore, quadratic compressors are optimal and robust with respect to a statistics of errors in a device under test