Using a Runtime Measurement Device with Measurement-Based WCET Analysis

The tough competition among automotive companies creates a high cost pressure on the OEMs. Combined with shorter innovation cycles, testing new safety-critical functions becomes an increasingly difficult issue [4]. In the automotive industry about 55% of breakdowns can be traced back to problems in electronic systems. About 30% of these incidents are estimated to be caused by timing problems [7]. It is necessary to develop new approaches for testing the timing behavior on embedded and real-time systems. This work describes the integration of runtime measurements using an external measurement device into a framework for measurement-based worst-case execution time calculations. We show that especially for small platforms using an external measurement device is a reasonable way to perform execution time measurements. Such platforms can be identified by the lack of a time source, limited memory, and the lack of an external interface. The presented device uses two pins on the target to perform run-time measurements. It works cycle accurate for frequencies up to 200MHz, which should be sufficient for most embedded devices.