Trace acquirement from real-time systems based on WCET analysis

Embedded real-time systems often operate under strict timing constraints. In order to test a real-time system thoroughly, we should instrument the system under test with assertions. Thus, the timing behaviors of such a system will change more or less. In this paper, we present two methods to weaken or even remove the timing related impact of the inserted assertions. Firstly, a new monitoring schema is presented which has less time intrusive than software motoring and can test the target system completely. This schema is a mixture of hardware monitoring and software monitoring. Secondly, in order to weaken the time intrusiveness of assertions as much as possible, we present a WCET analysis based time correction method. This method can compute the accurate execution time of assertions and corrects the recorded time of interested events.