A fault-tolerant program memory unit for on-board computer

The program memory of the on-board computer for satellite is susceptible to the space radiation effect. In order to overcome this problem, a reliable strategy to comprise a storage unit with NOR Flash was proposed for space application. And a fault-tolerant approach based on triple modular redundancy (TMR) was employed to correct the error by radiation effect. Meanwhile, several backup partitions were designed in the single-chip flash to further enhance the fault-tolerant ability of on-board computer. Another obstacle for TMR program memory system is how to download the program into each chip or partition on board with one download interface. A TMR-Switch program downloading method was proposed to overcome it by setting download data path and controlling memory partitions. Experiments on three NOR Flash chips and ZYNQ processor was conducted, and the results showed great capability in correcting faults in the onboard computer program file.