An Adaptive Fault-Tolerant Memory System for FPGA-based Architectures in the Space Environment

Ionizing radiation at high altitudes above the Earth adversely affects electronic systems in various ways. For these reasons, high-density, SRAM-based FPGA (field programmable gate array) systems have historically been unsuitable for use in space due to their higher susceptibility to radiation-induced soft error upsets (SEUs). However, there are a number of reasons for pursuing the deployment of adaptive FPGA-based designs in spacecraft systems and satellites. Frequently mission requirements change and FPGA systems are a mutable low-cost electronic fabric capable of adjusting to new design constraints after a system is initially released. Moreover, an adaptive FPGA design can attenuate the amount of fault tolerance in the system to the specific levels of radiation and the amount of available power, resources, and performance. Previously, the Triple3 Redundant Space Systems (T3RSS) approach demonstrated the use of partial reconfiguration of FPGA logic to ensure fault tolerance in FPGA-based space systems. This paper explores the issues germane to developing a reliable, high- performance memory system for FPGA architectures that seamlessly withstands both radiation-induced SEUs and permanent failures in space system hardware components.