Redundancy based interconnect duplication to mitigate soft errors in SRAM-based FPGAs

Soft error induced reliability problem has already become a major concern for modern SRAM-based FPGAs (Field Programmable Gate Arrays) even at the ground level. In this paper, we propose a duplication-with-recovery (DWR) technique to recover the configuration bit faults on interconnects, which contribute to the majority of soft errors in FPGAs. Based on a study on the detailed routing structure in real FPGAs, DWR leverages redundant resources for interconnect duplication and enables fault recovery with lightweight circuit-level support. Compared with traditional fault tolerant techniques, DWR retains the fault recovering capability but eliminates expensive copies. The experimental results show that a large portion of the interconnects can be protected, which in consequence significantly reduces the vulnerable configuration bits. In addition, DWR does not alter the placement and routing from standard design flow, and therefore does not affect the design closure but greatly improves the design reliability in a cost-effective way.