Soft Error Detection through Low-level Re-execution

Nowadays, embedded systems are widely used both in general-purpose as well as in safety-critical applications. Due to technological advances, these embedded systems can operate on extremely small footprints and low voltages. This, however, makes them more susceptible to external disturbances such as electromagnetic interference. These disturbances can cause single event upsets, a bit being flipped inside the microcontroller, which in turn can result in unexpected and unpredictable behavior of the system due to control flow errors or data flow errors. Many software-implemented control flow and data flow error detection techniques have been examined in the past. However, these techniques often require a large amount of devoted CPU registers to work correctly. Not every system is able to devote a large portion of its registers to an error detection technique. This paper proposes DETECTOR: a new low-level re-execution based technique protecting against both data flow and control flow errors, while using only three CPU registers. The experimental results presented in this paper are promising, showing that DETECTOR is able to significantly increase the reliability of the system.