Configurable 2‐D Linear Feedback Shift Registers for VLSI Built‐in Self‐test Designs
Chien‐In Henry Chen, Yingjie Zhou · VLSI design · 1999
Recently a multiple‐sequence test generator was presented based on two‐dimensional linear feedback shift registers (2‐D LFSR). This generator can generate a set of precomputed test vectors obtained by an ATPG tool for detecting random‐pattern‐resistant faults and particular hard‐to‐detect faults. In addition, it can generate better random patterns than a conventional LFSR. In this paper we describe an optimized BIST scheme which has a configurable 2‐D LFSR structure. Starting from a set of stuck‐at faults and a corresponding set of test vectors detecting these faults, the corresponding test pattern generator is determined automatically. A synthesis procedure of designing this test generator is presented. Experimental results show that the hardware overhead is considerably reduced compared with 2‐D LFSR generators.