Formulating MITF for a Multicore Processor with SEU Tolerance

While shrinking geometries of embedded LSI devices is beneficial for portable intelligent systems, it is increasingly susceptible to influences from electrical noise, process variation, and natural radiation interference. Even in consumer applications, modern embedded devices should be protected by dependable technologies. The challenging issue is there is a severe constraint in power consumption. As a platform to investigate the dependability, power, and performance trade-off, multiple clustered core processor (MCCP) is being investigated. It is a homogeneous multicore processor and has configurability in scale, which is beneficial for considering the trade-off. This paper focuses on how to explore the trade-off, and proposes to use mean instructions to failure (MITF) as a metric. To the best of our knowledge, this is the first study that formulates MITF for multicore processors. We compare three redundancy modes; undependable, thread-level redundancy, and instruction-level redundancy modes based on detailed simulations. As expected, thread-level redundancy shows largest MITF.