Compaction of a Functional Broadside Test Set through the Compaction of a Functional Test Sequence without Sequential Fault Simulation

Functional broadside tests avoid overtesting of delay faults by creating functional operation conditions during the clock cycles where they detect delay faults. One of the challenges in the generation of functional broadside tests is test compaction. Existing dynamic compaction approaches for scan tests are not applicable to functional broadside tests, and static compaction approaches are limited in the level of test compaction they can provide. The solution suggested in this paper has two new properties. (1) Instead of attempting to compact functional broadside tests, test compaction is applied to a functional test sequence from which functional broadside tests are extracted. The compact sequence yields a compact functional broadside test set. (2) Compaction of the functional test sequence is performed without sequential fault simulation. This is possible since test compaction does not have to preserve the fault coverage of the functional test sequence. The solution is developed in the scenario where the primary input vectors of a circuit are not constrained during functional operation. Experimental results for benchmark circuits demonstrate its ability to compact a functional broadside test set for transition faults.