Design method of a class of embedded combinational self-testing checkers for two-rail codes

This paper tackles the open problem of designing combinational self-testing checkers (STCs) for K-pair 2-rail codes which are self-testing, even by a subset of codewords, such that some input lines are 0 (or 1) for only one input codeword. The checker presented in the paper has both theoretical and practical importance. It is useful, for example, to build STCs for other systematic error-detecting codes, like Berger codes with I = 2/sup K-1/ data bits and arithmetic codes with the check base A = 2/sup K-1/+I (K = 3, 4, 5, ...). It also allows the designers to build functional totally self-checking circuits with 100% fault coverage in which such 2-rail codes could not have been used otherwise.