Using Timing Analysis for Evaluating Communication Behavior and Network Topologies in an Early Design Phase of Automotive Electric/Electronic Architectures

The increasing functionality and complexity of future electric/electronic architectures requires efficient methods and tools to support design decisions, which are taken in early development phases 6. For the past four years, a holistic approach for architecture development has been established at Mercedes-Benz Cars R&D department. At its core is a seamless design flow, including the conception, the analysis and the documentation for electric/electronic architectures. One of the actual challenges in the design of electric/electronic architectures concerns communication behavior and network topologies. The increasing data exchange between the ECUs creates high requirements for the networks. With the introduction of FlexRay 21 and Ethernet the automotive network architecture become a lot more heterogeneous. Especially gateways must fulfill many new requirements to handle the strict periodic schedule of FlexRay and the partly event-triggered communication on CAN-busses 23. Key questions in this context include: busload, communication relations between the ECUs, the timing behavior of a network domain or of the whole network.

One possibility is to offer the system engineer a first feeling about the timing behavior of the network by using timing analysis methods. This paper discusses the usage of scheduling analysis as a suitable technique for evaluating communication behavior and network topologies in an early design phase of automotive electric/electronic architectures.

The paper mainly focuses on the set of data necessary to get good analysis results, and which set of data can be provided in an early phase of network design. A second, aspect concerns the tool coupling between an established architecture tool (PREEvision by Aquintos) and a novel timing-analysis tool (SymTA/S by Symtavision).