Real-Time Redundant Scrubbing (RRS) System for Radiation Protection on SRAM-Based FPGA

SRAM-based Field Programmable Gate Array (FPGA) is vulnerable to the serious radiation effects represented by Single Event Upset (SEU) effect in space. Triple Modular Redundancy (TMR) and configuration scrubbing are effective methods of FPGA radiation protection, but each has its own shortcomings: TMR structure can’t correct errors, and scrub circuit, also called “scrubber”, is sensitive to radiation. In response to the problem, this paper proposes a Real-time Redundant Scrubbing (RRS) system. Based on the traditional configuration scrubbing, TMR structure is applied to the scrubber. And the error indicator is added to the traditional TMR structure. When the scrubber has errors due to SEU, the scrubber will be scrubbed in real-time to prevent error accumulation. In addition, the floorplan of the three redundant logic is distributed to avoid the influence of a SEU on multiple redundant logic at the same time. In this paper, the anti-radiation capability of the proposed RRS system is evaluated by random fault injection. The test results show that the anti-radiation capability of the RRS system is more than 2 times higher than that of traditional configuration scrubbing system.