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More electronic vehicle functions lead to an exponentially growing degree of software integration in automotive ECUs. We are seeing an increasing number of ECUs with mixed criticality software. ISO26262 describes different safety requirements, including freedom from interference and absence from error propagation for the software. These requirements mandate particular attention for mixed-criticality ECUs. In this paper we investigate the ability to guarantee that these safety requirements will be fulfilled by using established (deadline monitoring) and new error detection mechanisms (execution time monitoring). We also show how these methods can be used to build up safe and efficient schedules for today's and future automotive embedded real time systems with mixed criticality software.

With the increasing complexity of electronic vehicle systems, one particular “gap” between function development and ECU integration becomes more and more apparent, and critical; albeit not new. The core of the problem is: as more functions are integrated and share the same E/E resources, they increasingly mutually influence and disturb each other in terms of memory, peripherals, and also timing and performance. This has two consequences: The amount of timing-related errors increases (because of the disturbance) and it becomes more difficult to find root causes of timing errors (because of the mutual influences). This calls for more systematic methods to deal with timing requirements in general and their transformation from function timing requirements to software architecture timing requirements in particular.