Multi-Threaded Mitigation of Radiation-Induced Soft Errors in Bare-Metal Embedded Systems

This article presents a software protection technique against radiation-induced faults which is based on a multi-threaded strategy. Data triplication and instructions flow duplication or triplication techniques are used to improve system reliability and thus, ensure a correct system operation. To achieve this objective, a relaxed lockstep model to synchronize the execution of both, redundant threads and variables under protection on different processing units is defined. The evaluation was performed by means of simulated fault injection campaigns in a multi-core ARM system. Results show that despite being considered techniques that imply an evident overhead in memory and instructions (Duplication With Comparison and Re-Execution – DWC-R and Triple Modular Redundancy – TMR), spreading the replicas in different instruction flows not only produce similar results than classic techniques, but also improves the computational and recovery time in presence of soft-errors. In addition, this paper highlights the importance of protecting memory-allocated data, since the instruction flow triplication is not enough to improve the overall system reliability.