FlexRay - From Principles to Products

Electronics in vehicles are an ongoing success story. Over the last years the in-vehicle network that interconnects the electronic subsystems has developed into a key constituent of the overall electronic vehicle architecture. Over the last years an industry consortium of more than 120 companies has developed the FlexRay Communications System - a time-deterministic protocol with a data rate of 10MBit/s for advanced control systems in vehicles.

In this paper we briefly recap the history of this development and provide the main rationales for the protocol mechanisms as they are defined today. While the FlexRay Protocol itself is defined rigorously using the formal Specification and Description Language SDL the FlexRay Communications System provides certain degrees of freedom in the design of the controller host interface that interfaces the FlexRay Protocol to the higher application levels. We discuss how the provided degrees of freedom are utilized in the controller host interface of a concrete FlexRay communications controller implementation. In addition we address not only the benefits but also the implications that the controller host interface has on automotive software, such as in the context of AUTOSAR. The paper concludes with a discussion of how these standards have in the past and may in the future define the way that related products are defined and launched into the automotive industry.