Test compaction by test cube merging for four-way bridging faults

Abstract

Test compaction that accommodates the constraints of test data compression can be achieved by generating test cubes for target faults, and then merging the test cubes. This paper describes an improved test cube merging procedure for four-way bridging faults. The procedure is motivated by the prevalence of bridging defects and the fact that test sets for bridging faults are larger than test sets for single stuck-at faults. A four-way bridging fault g i /a i /h i models the case where a value a i of a line h i dominates the value of a line g i . A basic test cube merging procedure considers a set of test cubes C det that detects target faults. The paper extends the set of test cubes to include, in addition to C det , a set of test cubes C dom that assign values to dominating lines. Test cubes from C dom have significantly fewer specified values than test cubes from C det . When test cubes from C dom are merged with test cubes from C det , each resulting test cube detects more faults, and fewer test cubes are needed for detecting the same set of target faults.