Power/Area-Optimized Fault Tolerance for Safety Critical Applications

Increasing the reliability of a system always comes with a high price in performance/power/area overhead. Enabling error detection and correction features can be obtained by employing different kinds of redundancy including hardware, time, information, software or some combination of them. In many cases the imposed overhead is enormous. Fault tolerance is an important requirement for safety critical applications (e.g., automated driving), but significant power/area overhead is not acceptable. This paper summarizes several strategies and methods how to reduce the introduced overhead, while still providing a respectable level of fault tolerance features. Two main methodologies are discussed: static and dynamic. Static methods address the overhead by performing a static trade-off between the achieved level of fault tolerance and the introduced overhead. Dynamic methods on the other hand are based on the actual application requirement, and are dynamically varying the required overhead to fulfill the safety requirements of the application. This paper summarizes practical examples and results in this field.