Fault tolerant computing for stream DSP applications using GALS multi-core processors

This paper presents a multi-core processor with globally asynchronous locally synchronous (GALS) clocking style designed to achieve soft error tolerance for stream DSP applications, and to maintain system throughput energy efficiently. Each processor in the chip can be combined with one of its neighbor processors to run the same programs and their results are equivalence checked to detect the soft error occurrence. When error occurs in some processor, the program in that processor (not the whole chip) is re-executed from the saved state to recover from the error. Due to the programming model of stream DSP applications, each processor can be isolated by FIFOs in the proposed multi-core processors, and fault detection and recovery can be done with low overhead. Furthermore, the GALS clocking style allows adjusting the frequency of the processors hit by a soft error-not the frequency of the whole chip-to maintain the system throughput, which results high energy efficiency.