Low-power test compression for launch-on-capture transition fault testing

Abstract

A new low-power test compression method and design for testability (DFT) architecture are proposed for deterministic test pairs for launch-on-capture (LOC) transition fault testing by using a new seed encoding scheme, a new low-power test application procedure and a new test compression architecture. The new seed encoding scheme generates seeds for all test pairs by selecting a primitive polynomial that encodes all test pairs of a compact test set. The low-power test compression architecture includes: (1) the LFSR established by the selected primitive polynomial and the selected number of extra variables injected to the LFSR; (2) the scan tree architecture for LOC transition fault testing; and (3) the new gating technique. A new static test compaction scheme is proposed by bitwise modifying the values of a seed and the extra variables. A new technique for test point insertion is proposed for LOC delay testing in the two-frame-circuit model, which apparently reduces test data volume.