B-algorithm: a behavioral test generation algorithm

A behavioral test generation algorithm (called the B-algorithm) is presented which generates tests directly from behavioral VHDL circuit descriptions using three types of behavioral faults (behavioral stuck-at faults, behavioral stuck-open faults, and micro-operation faults). Behavioral faults are defined by perturbing VHDL constructs. In particular, behavioral stuck-at faults are defined for virtual signals corresponding to expressions as well as for normal signals. The B-algorithm generates tests using three basic test generation operations (activation, propagation, and justification), which are systematically executed by manipulating three data structures (B-frontier, J-frontier, and A-queue). Rules for the test generation operations are defined using the concepts of two-phase activation and two-phase propagation. The B-algorithm has two unique features. First, it can generate tests for behavioral stuck-open faults, which in fact can detect some gate level transition faults. Second, it incorporates the concept of two-phase testing, a testing strategy where a fault is detected using two consecutive test sequences