A novel delay fault testing methodology using low-overhead built-in delay sensor

Swaroop Ghosh, Swarup Bhunia, Arijit Raychowdhury, Kaushik Roy

Research output: Contribution to journalArticlepeer-review

37 Scopus citations


A novel integrated approach for delay-fault testing in external (automatic-test-equipment-based) and test-per-scan built-in self-test (BIST) using on-die delay sensing and test point insertion is proposed. A robust, low-overhead, and process-tolerant on-chip delay-sensing circuit is designed for this purpose. An algorithm is also developed to judiciously insert delay-sensor circuits at the internal nodes of logic blocks for improving delay-fault coverage with little or no impact on the critical-path delay. The proposed delay-fault testing approach is verified for transition- and segment-delay-fault models. Experimental results for external testing (BIST) show up to 31% (30%) improvement in fault coverage and up to 67.5% (85.5%) reduction in test length for transition faults. An increase in the number of robustly detectable critical-path segments of up to 54% and a reduction in test length for the segment-delay-fault model of up to 76% were also observed. The delay and area overhead due to insertion of the delay-sensing hardware have been limited to 2% and 4%, respectively.

Original languageEnglish (US)
Pages (from-to)2934-2943
Number of pages10
JournalIEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Issue number12
StatePublished - Dec 2006

All Science Journal Classification (ASJC) codes

  • Software
  • Computer Graphics and Computer-Aided Design
  • Electrical and Electronic Engineering


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