Research On Software Fault-Tolerance Of COTS Microprocessor

The American ARGOS satellite had done experiments on the primary anti-radiation measures of COTS components, and had obtained valuable experiment data. The experiments have demonstrated that it's possible to satisfy the requirement of space applications by software techniques without special hardware. This conclusion makes the COTS components more applicable in spacecrafts. How to select the best one from many excellent COTS components used in spacecrafts has been an important issue in space system research. Microprocessor is the core component in spacecrafts. Therefore, it's necessary to study the architecture of microprocessor , the fault tolerance and performance overhead, when the software fault-tolerance techniques is applied in the COTS microprocessors, and then select the best, which is very helpful in selecting the microprocessor applied in the spacecrafts in the future.EDDI and CFCSS, two key techniques of the SIHFT technique and the architecture of ARM7 and SPARC V8 are researched in this dissertation. Based on the research, the fault tolerance and performance overhead are compared when the SIHFT technique is applied on the two microprocessors, and the requirements of the suitable microprocessors are proposed. And then the chief technique problems when the SIHFT technique is applied on SPARC V8 are analyzed, the solution algorithms and the technical scheme are proposed. At last, the simulated experiments on the target platform have been done to test the fault detection coverage of suitable software fault-tolerance technique. The experiment data on the TSIM simulator has shown that with average 133.2% overhead, the fault detection coverage of the software fault tolerance technique is 95.3% when faults are injected into registers, and 79.8% when faults are injected into memory, which proved that the SIHFT technique is valid. Because the data of the experiment on the ARM7 is not complete, there is no way to compare two platforms quantitatively. But the performance of SPARC V8 is better than ARM7's, which obtained by the theoretical analyses. The conclusion is to be proven by further experiments.