A Built-in Reseeding Technique for LFSR-Based Test Pattern Generation

Youhua SHI  Zhe ZHANG  Shinji KIMURA  Masao YANAGISAWA  Tatsuo OHTSUKI  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E86-A    No.12    pp.3056-3062
Publication Date: 2003/12/01
Online ISSN: 
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on VLSI Design and CAD Algorithms)
Category: Timing Verification and Test Generation
reseeding,  LFSR,  BIST,  test pattern generation,  

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Reseeding technique is proposed to improve the fault coverage in pseudo-random testing. However most of previous works on reseeding is based on storing the seeds in an external tester or in a ROM. In this paper we present a built-in reseeding technique for LFSR-based test pattern generation. The proposed structure can run both in pseudorandom mode and in reseeding mode. Besides, our method requires no storage for the seeds since in reseeding mode the seeds can be generated automatically in hardware. In this paper we also propose an efficient grouping algorithm based on simulated annealing to optimize test vector grouping. Experimental results for benchmark circuits indicate the superiority of our technique against other reseeding methods with respect to test length and area overhead. Moreover, since the theoretical properties of LFSRs are preserved, our method could be beneficially used in conjunction with any other techniques proposed so far.