Simulation based test generation for scan designs

We describe a simulation-based test generation procedure for scan designs. A test sequence generated by this procedure consists of a sequence of one or more primary input vectors embedded between a scan-in operation and a scan-out operation. We consider the set of faults that can be detected by test sequences of this form, compared to the case where scan is applied with every test vector. The proposed procedure constructs test sequences that traverse as many pairs of fault-free/faulty states as possible, and thus avoids the use of branch-and-bound test generation techniques. Additional techniques are incorporated into this basic procedure to enhance its effectiveness.