A selective scan chain reconfiguration through run-length coding for test data compression and scan power reduction

Research output: Contribution to journalArticle


Test data volume and power consumption for scan-based designs are two major concerns in system-on-a-chip testing. However, test set compaction by filling the don't-cares will invariably increase the scan-in power dissipation for scan testing, then the goals of test data reduction and low-power scan testing appear to be conflicted. Therefore, in this paper we present a selective scan chain reconfiguration method for test data compression and scan-in power reduction. The proposed method analyzes the compatibility of the internal scan cells for a given test set and then divides the scan cells into compatible classes. After the scan chain reconfiguration a dictionary is built to indicate the run-length of each compatible class and only the scan-in data for each class should be transferred from the ATE to the CUT so as to reduce test data volume. Experimental results for the larger ISCAS'89 benchmarks show that the proposed approach overcomes the limitations of traditional run-length coding techniques, and leads to highly reduced test data volume with significant power savings during scan testing in all cases.

Original languageEnglish
Pages (from-to)3208-3214
Number of pages7
JournalIEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences
Issue number12
Publication statusPublished - 2004 Dec



  • Run-length coding
  • Scan chain reconfiguration
  • Scan-in power consumption
  • Test data compression

ASJC Scopus subject areas

  • Signal Processing
  • Computer Graphics and Computer-Aided Design
  • Electrical and Electronic Engineering
  • Applied Mathematics

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