A New Hybrid Nonintrusive Error-Detection Technique Using Dual Control-Flow Monitoring

Hybrid error-detection techniques combine software techniques with an external hardware module that monitors the execution of a microprocessor. The external hardware module typically observes the control flow at the input or at the output of the microprocessor and compares it with the expected one. This paper proposes a new hybrid technique that monitors the control flow at both points and compares them to detect possible errors. The proposed approach does not require any software modification to detect control-flow errors. Fault-injection campaigns have been performed on an LEON3 microprocessor. The results show full control-flow error detection with no performance degradation and small area overhead. A complete solution can be obtained by complementing the proposed approach with software fault-tolerance techniques for data errors.