Reconfigurable Fault Tolerance

Commercial SRAM-based, field-programmable gate arrays (FPGAs) have the potential to provide space applications with the necessary performance to meet next-generation mission requirements. However, mitigating an FPGA’s susceptibility to single-event upset (SEU) radiation is challenging. Triple-modular redundancy (TMR) techniques are traditionally used to mitigate radiation effects, but TMR incurs substantial overheads such as increased area and power requirements. In order to reduce these overheads while still providing sufficient radiation mitigation, we propose a reconfigurable fault tolerance (RFT) framework that enables system designers to dynamically adjust a system’s level of redundancy and fault mitigation based on the varying radiation incurred at different orbital positions. This framework includes an adaptive hardware architecture that leverages FPGA reconfigurable techniques to enable significant processing to be performed efficiently and reliably when environmental factors permit. To accurately estimate upset rates, we propose an upset rate modeling tool that captures time-varying radiation effects for arbitrary satellite orbits using a collection of existing, publically available tools and models. We perform fault-injection testing on a prototype RFT platform to validate the RFT architecture and RFT performability models. We combine our RFT hardware architecture and the modeled upset rates using phased-mission Markov modeling to estimate performability gains achievable using our framework for two case-study orbits.