Low cost scan test by test correlation utilization

Research output: Contribution to journalArticlepeer-review


Scan-based testing methodologies remedy the testability problem of sequential circuits; yet they suffer from prolonged test time and excessive test power due to numerous shift operations. The correlation among test data along with the high density of the unspecified bits in test data enables the utilization of the existing test data in the scan chain for the generation of the subsequent test stimulus, thus reducing both test time and test data volume. We propose a pair of scan approaches in this paper; in the first approach, a test stimulus partially consists of the preceding stimulus, while in the second approach, a test stimulus partially consists of the preceding test response bits. Both proposed scan-based test schemes access only a subset of scan cells for loading the subsequent test stimulus while freezing the remaining scan cells with the preceding test data, thus decreasing scan chain transitions during shift operations. The proposed scan architecture is coupled with test data manipulation techniques which include test stimuli ordering and partitioning algorithms, boosting test time reductions. The experimental results confirm that test time reductions exceeding 97%, and test power reductions exceeding 99% can be achieved by the proposed scan-based testing methodologies on larger ISCAS89 benchmark circuits.

Original languageEnglish (US)
Pages (from-to)681-694
Number of pages14
JournalJournal of Computer Science and Technology
Issue number5
StatePublished - Sep 2007


  • Scan architecture design
  • Scan-based testing
  • Test correlation
  • Test data compression

ASJC Scopus subject areas

  • Software
  • Theoretical Computer Science
  • Hardware and Architecture
  • Computer Science Applications
  • Computational Theory and Mathematics


Dive into the research topics of 'Low cost scan test by test correlation utilization'. Together they form a unique fingerprint.

Cite this