Design of test sequences for VLSI self-testing using LFSR

Consider a shift register (SR) of length n and a collection of designated subsets of (0,1, . . ., n-1). The problem is how to add feedback to the SR such that the resulting linear feedback shift register (LFSR) exercises (almost) exhaustively each of the designated subsets and is of small period. Several previously known results for maximum-length LFSR are extended to more general LFSR, and in particular a previously known algorithm is simplified and extended. Applications to the problems of VLSI self-testing are discussed and illustrated.>