Simulation coverage enhancement using test stimulus transformation

This paper introduces the concept of abstract state exploration histories to a simulation environment, and presents a test stimulus transformation (TST) technique to improve simulation coverage. State exploration histories are adapted from reachability analysis in Formal Verification. In TST, an aggressively abstracted state exploration history is maintained during simulation. While this history is being collected, test stimuli from an existing test bench are transformed on-the-fly to explore new scenarios that are not in the history. The results showed that 3-fold increase in transition coverage for a cache coherence controller, and 10 times faster coverage convergence for a MPEG2 decoder can be achieved.