TEST EFFECTIVENESS

摘要

SDD (small-delay-defect) ATPG (automatic-test-pattern generation) produces two distinct coverage metrics-test coverage and delay effectiveness-to reflect the test effectiveness of the pattern set. The test coverage of TD (transition-delay) faults is the percentage of the total testable delay faults that ATPG detects: Test coverage= DT/(all faults-UD-AU), where DT is the number of detected faults and UD and AU are the undetectable and ATPG-untestable faults, respectively, that you subtract from the total number of faults. These faults include those in the special SDD-ATPG subcategory of TP (transition partially detected), in addition to DS (detected by simulation) faults detected along their longest paths or paths with slacks satisfying the extended criterion for detection.