Test requirement analysis for low cost hierarchical test path construction

We propose a methodology that examines design modules and identifies appropriate vector justification and response propagation requirements for reducing the cost of hierarchical test path construction. Test requirements are defined as a set of fine-grained input and output bit clusters and pertinent symbolic values. They are independent of actual test sets and are adjusted to the inherent module connectivity and regularity. As a result, they combine the generality required for fast hierarchical test path construction with the precision necessary for minimizing the incurred cost, thus fostering cost-effective hierarchical test.