Robust paradigm for diagnosing hold-time faults in scan chains
Chao-Wen Tzeng, Jiunn Hsu, Shi-Yu Huang · IET Computers & Digital Techniques · 2007
Hold-time violation is a common cause of failure at scan chains. A robust new paradigm for diagnosing such failures is presented. As compared to previous methods, the main advantage of this is the ability to tolerate non-ideal conditions, for example, under the presence of certain core logic faults or for those faults that manifest themselves intermittently. The diagnosis problem is first formulated as a ‘delay insertion process’. Upon this formulation, two algorithms – a ‘greedy’ algorithm and a so-called ‘best-alignment-based’ algorithm – is proposed. Experimental results on a number of practical designs and ISCAS'89 benchmark circuits are presented to demonstrate its effectiveness.