Multi-context scrubbing method

Abstract

Two salient concerns of current field programmable gate arrays (FPGAs) used for space applications are how to block soft errors that arise on their configuration memories and how to treat permanent failures attributable to total dose effects. To date, those two main concerns have been treated separately, but we present a proposal for multi-context scrubbing to “kill two birds with one stone” and resolve both issues simultaneously. To decrease the frequency of soft errors arising on the configuration memories of FPGAs, applying scrubbing operations for configuration memories is extremely useful. Since faster scrubbing can increase the radiation tolerances of the configuration memories on FPGAs, optical high-speed scrubbing using optically reconfigurable gate array (ORGA) architecture is introduced. Up to now, major scrubbing operations have invariably used a single configuration context, but since the storage capacities of holographic memories on ORGAs are high, many configuration contexts can be stored on a holographic memory. Thereby, various configuration contexts that avoid permanent failures can be used cyclically for scrubbing operations. Even if a permanent failure occurs on the programmable gate array during scrubbing operations, which exploit numerous configuration contexts, correct operations can be executed.