Comparison and application of different VHDL-based fault injection techniques

Compares different VHDL-based fault injection techniques: simulator commands, saboteurs and mutants for the validation of fault tolerant systems. Some extensions and implementation designs of these techniques have been introduced. Also, a wide set of non-usual fault models have been implemented. As an application, a fault tolerant microcomputer system has been validated. Faults have been injected using an injection tool developed by the GSTF. We have injected both transient and permanent faults on the system model, using two different workloads. We have studied the pathology of the propagated errors, measured their latencies, and calculated both detection and recovery coverages. Preliminary results show that coverages for transient faults can be obtained quite accurately with any of the three techniques. This enables the use of different abstraction level models for the same system. We have also verified significant differences in implementation and simulation cost between the studied injection techniques.