The fault tolerance approach of the Advanced Architecture Onboard Processor

The Advanced Architecture Onboard Processor is a fault-tolerant multiprocessor for space applications that is based on a fault-tolerant chordal skip-link ring interconnect network. Low-power self-checking circuits in each processor node are combined with distributed reconfiguration control and local rollback recovery to achieve robust fault tolerance within spacecraft weight and power constraints. A ten-processor-node breadboard has been completed. The approach to fault tolerance and the tradeoff analysis leading to the selected implementation are covered. Analytical trade study results such as redundancy overhead as a function of system partitioning for the chordal skip-link ring are discussed.<>