A Design for Testability Technique for Low Power Delay Fault Testing

James Chien-Mo LI  

IEICE TRANSACTIONS on Electronics   Vol.E87-C   No.4   pp.621-628
Publication Date: 2004/04/01
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Low-Power System LSI, IP and Related Technologies)
testability technology (design for testability),  delay fault testing,  low power,  ASIC,  

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This paper presents a Quiet-Noisy scan technique for low power delay fault testing. The novel scan cell design provides both the quiet and noisy scan modes. The toggling of scan cell outputs is suppressed in the quiet scan mode so the power is saved. Two-pattern tests are applied in the noisy scan mode so the delay fault testing is possible. The experimental data shows that the Quiet-Noisy scan technique effectively reduces the test power to 56% of that of the regular scan. The transition fault coverage is improved by 19.7% compared to an existing toggle suppression low power technique. The presented technique requires very minimal changes in the existing MUX-scan Design For Testability (DFT) methodology and needs virtually no computation. The penalties are area overhead, speed degradation, and one extra control in test mode.