Computer aided design of fault-tolerant application specific programmable processors

Application Specific Programmable Processors (ASPP) provide efficient implementation for any of m specified functionalities. Due to their flexibility and convenient performance-cost trade-offs, ASPPs are being developed by DSP, video, multimedia, and embedded lC manufacturers. In this paper, we present two low-cost approaches to graceful degradation-based permanent fault tolerance of ASPPs. ASPP fault tolerance constraints are incorporated during scheduling, allocation, and assignment phases of behavioral synthesis: Graceful degradation is supported by implementing multiple schedules of the ASPP applications, each with a different throughput constraint. In this paper, we do not consider concurrent error detection. The first ASPP fault tolerance technique minimizes the hardware resources while guaranteeing that the ASPP remains operational in the presence of all k-unit faults. On the other hand, the second fault tolerance technique maximizes the ASPP fault tolerance subject to constraints on the hardware resources. These ASPP fault tolerance techniques impose several unique tasks, such as fault-tolerant scheduling, hardware allocation, and application-to-faulty-unit assignment. We address each of them and demonstrate the effectiveness of the overall approach, the synthesis algorithms, and software implementations on a number of industrial-strength designs.