基于冷备份多模冗余结构的BRAM自修复方法

随着现场可编程门阵列（FPGA）在空天电子系统中的广泛应用，受空间辐射恶劣环境影响，FPGA中重要的存储器电路BRAM，因采用SRAM技术极易发生位翻转故障，虽绝大部分情况表现为瞬时故障，但永久故障依然存在。针对BRAM自修复方法仅修复瞬时故障的现状，对能同时修复瞬时故障和永久故障的自修复方法进行研究，提出了一种冷备份多模冗余结构，用3个热备份模块和1个冷备份模块来构造BRAM，该结构可通过三模冗余刷新方法修复瞬时故障和冷备份替换方法修复永久故障。给出了整个BRAM自修复系统中各模块的电路结构和实现方法，实验验证了系统的自修复能力，并在可靠性、硬件资源和时间消耗3个方面，通过对比分析论证了自修复方法的有效性。

Self-repairing method for BRAM based on cold backup multi-mode redundancy structure

FPGAs have gained widespread application in the aerospace electronic system. Affected by the harsh radiation environment of the space, the important memory circuit BRAM in FPGAs is prone to bit flip failure due to the adoption of SRAM technology. Despite the large proportion of transient faults, permanent faults still exist. Since the current BRAM self-repairing methods address only transient faults, we study a self-repairing method that can simultaneously repair both transient and permanent faults. A cold backup multi-mode redundancy structure using three hot backup modules and one cold backup module to construct BRAM is proposed to repair transient faults through TMR-Scrubbing and permanent faults by cold-backup-replacement. The circuit structure and implementation method of each module in the entire BRAM self-repairing system have been presented, and the self-repairing ability of the system has been verified through experiments. The effectiveness of the method in terms of reliability, hardware resources and time consumption has been verified through comparative analysis.