Reliability analysis of radiation induced fault mitigation strategies in field programmable gate arrays

Abstract

This dissertation presents the results of engineering design and analysis of a radiation tolerant, static random-access-memory-based field programmable gate array reconfigurable computer system for use in space flight applications. A custom satellite platform was designed and developed at Montana State University. This platform facilitates research into radiation tolerant computer architectures that enable the use of commercial off-the-shelf components in harsh radiation environments. The computer architectures are implemented on a Xilinx Virtex-6 field programmable gate array, the configuration of which is controlled by a Xilinx Spartan-6 field programmable gate array. These architectures build upon traditional triple modular redundancy techniques through the addition of spare processing resources. The logic fabric is partitioned into discrete, reconfigurable tiles with three tiles active in triple modular redundancy and remaining tiles maintained as spares. A voter circuit identifies design-level faults triggering rapid switch to a spare tile. Blind or readback scrubbing prevents the accumulation of configuration memory faults. The design and results from a variety of integrated system tests are presented as well as a reliability analysis of the radiation effects mitigation strategy used in the system. The research questions addressed by this dissertation are: 1) Does the inclusion of spare circuitry increase system reliability? 2) How do single-points-of-failure affect system reliability? and 3) Does migrating single-points-of-failure to an older technology node (technology partitioning) offer an improvement in reliability?