Automating the processes of selecting an appropriate scheduling algorithm and configuring the scheduler implementation for time-triggered embedded systems

Predictable system behaviour is a necessary (but not sufficient) condition when creating safety-critical and safety-related embedded systems. At the heart of such systems there is usually a form of scheduler: the use of time-triggered schedulers is of particular concern in this paper. It has been demonstrated in previous studies that the problem of determining the task parameters for such a scheduler is NP-hard. We have previously described an algorithm (“TTSA1”) which is intended to address this problem. This paper describes an extended version of this algorithm (“TTSA2”) which employs task segmentation to increase schedulability. We show that the TTSA2 algorithm is highly efficient when compared with alternative “branch and bound” search schemes.