Automatic Generation of Schedulings for Improving the Test Coverage of Systems-on-a-Chip

SystemC is becoming a de-facto standard for the early simulation of systems-on-a-chip (SoCs). It is a parallel language with a scheduler. Testing a SoC written in SystemC implies that we execute it, for some well chosen data. We are bound to use a particular deterministic implementation of the scheduler, whose specification is non-deterministic. Consequently, we may fail to discover bugs that would have appeared using another valid implementation of the scheduler. Current methods for testings SoCs concentrate on the generation of the inputs, and do not address this problem at all. We assume that the selection of relevant data is already done, and we generate several schedulings allowed by the scheduler specification. We use dynamic partial-order reduction techniques to avoid the generation of two schedulings that have the same effect on the system´s behavior. Exploring alternative schedulings during testing is a way of guaranteeing that the SoC description, and in particular the embedded software, is scheduler-independent, hence more robust. The technique extends to the exploration of other non-fully specified aspects of SoC descriptions, like timing