Run-Time Reconfigurable Fault Tolerant Architecture for Soft-Core Processor NEO430

Redundancy (TMR). SRAM FPGAs are susceptible to Single Event Upsets (SEUs) which are the most common transient faults induced by the cosmic radiation. Therefore, SEU mitigation strategy is required when SRAM FPGAs are integrated into safety-critical systems. An essential requirement for these systems is often to remain fail-operational and thus, to perform implemented functionality after the occurrence of a fault. In this paper, we propose a run-time reconfigurable FT architecture based on coarse-grained TMR with triplicated soft-core processor NEO430 core, PDR for removing all transient SEU faults and the state synchronization allowing smooth state recovery from the inconsistent state when the reconfiguration of a failed processor instance was finished into the state where all three processors operate synchronously. The paper describes implemented FT architecture and run-time fault recovery strategy performing all necessary steps without additional blocking of the system functionality. The state synchronization for the soft-core processor NEO430 architecture is described in a further detail. Moreover, the paper presents developed PDR framework used for validation and testing of proposed fault recovery strategy.