Fault simulation with parallel exact critical path tracing in multiple core environment

A novel fault simulation method is proposed, based on exact critical path tracing beyond the Fan-out-Free Regions (FFR) throughout the full circuit. The method exploits two types of parallelism: bit-level parallelism for multiple pattern reasoning, and distribution the fault reasoning process between different cores in a multi-core processor environment. To increase the speed and accuracy of fault simulation, compared with previous methods, a mixed level fault reasoning approach is developed, were the fan-out re-convergence is handled on the higher FFR network level, and the fault simulation inside of FFRs relies on the gate-level information. To allow a uniform and seamless fault reasoning, Structurally Synthesized BDDs (SSBDD) are used for modeling on both levels. Experimental research demonstrated very promising results in increasing the speed and scalability of the method.