Controller Area Network (CAN) Schedulability Analysis with FIFO queues

Robert Davis1,  Steffen Kollmann2,  Victor Pollex2,  Frank Slomka2
1University of York, 2Ulm University


Controller Area Network (CAN) is widely used in automotive applications. Existing schedulability analysis for CAN is based on the assumption that the highest priority message ready for transmission at each node on the network will be entered into arbitration on the bus. However, in practice, some CAN device drivers implement FIFO rather than priority-based queues invalidating this assumption. In this paper, we introduce response time analysis and optimal priority assignment policies for CAN messages in networks where some nodes use FIFO queues while other nodes use priority queues. We show, via a case study, the impact that FIFO queues have on the real-time performance of CAN.