Improving the Robustness of a Softcore Processor against SEUs by Using TMR and Partial Reconfiguration

Abstract

SRAM-based field programmable gate arrays (FPGAs) are vulnerable to a single event upset (SEU), which is induced by radiation effect. This paper presents a technique for ensuring reliable softcore processor implementation on SRAM-based FPGAs. Although an FPGA is susceptible to SEUs, these faults can be corrected as a result of its reconfigurability. We propose techniques for SEU mitigation and recovery of a softcore processor using triple modular redundancy (TMR) and partial reconfiguration (PR) with state synchronization. By carrying out an experiment, we confirm that a faulty softcore processor can be recovered and synchronized with other softcore processors. The proposed technique requires 4.315 times the resource usage and 62.491% of the operating frequency of the base processor. However, the proposed recovery process only takes 6 μs under TMR and PR. As a result of reliability estimation, the proposed system achieved about 2.713 times longer MTBF comparing with the previous system.