Fault-Tolerant, Radiation-Hard DSP

Commercial digital signal processors (DSPs) for use in high-speed satellite computers are challenged by the damaging effects of space radiation, mainly single event upsets (SEUs) and single event functional interrupts (SEFIs). Inno vations have been developed for mitigating the effects of SEUs and SEFIs, enabling the use of very-high-speed commercial DSPs with improved SEU tolerances. Timetriple modular redundancy (TTMR) is a method of applying traditional triple modular redundancy on a single processor, exploiting the VLIW (very long instruction word) class of parallel processors. TTMR improves SEU rates substantially. SEFIs are solved by a SEFI-hardened core circuit, external to the microprocessor. It monitors the “health” of the processor, and if a SEFI occurs, forces the processor to return to performance through a series of escalating events.