FlexRay Transceiver Behavior Modeling for Virtual Hardware Prototyping and Verification of Vehicle FlexRay Network Topologies

FlexRay is an emerging communication technology used within Automotive In-Vehicle networking applications. However consideration of environmental variations, as well as device and overall system tolerances make development of a robust FlexRay network a daunting task. Even if the hardware prototype was available it may not be practical nor possible, to test and measure all the possible variations of network performance over this large multidimensional parameter space. But if simulation via a virtual hardware prototype accurately captured the FlexRay physical layer implementation concept, worst-case scenarios and corner cases could be efficiently investigated in face of any random or user selected combination of device and system variations. For simulation to be a viable option, the models for all the network components need to be available. A crucial component is the complex multifunctional FlexRay transceiver, as this device significantly impacts the quality of the overall network implementation and the signal integrity of the topology. This paper illustrates techniques employed to model the TJA1080 FlexRay transceiver, which was selected as it is well-known and entrenched in FlexRay design communities worldwide. Mixed-Signal Hardware Description Language (MSHDL) and macro-modeling techniques will demonstrate how it is possible to rapidly develop building blocks, which are assembled to construct a simulation component model that mirrors in entirety all the TJA1080 functionality. Because the features of the device are extensive, a diagnostic mode is inserted to permit observation of all relevant transitions and mode activity within its internal state machine. This enhances the value and efficiency of simulation as a tool for debugging the implementation of the FlexRay transceiver within the network configuration. Due to temperature dependent asymmetries of the receiver and transmitter stages, consideration of dynamic temperature effects is important, and to account for manufacturing process variations, statistical modeling is implemented. Finally validation of the simulated TJA1080 transceiver component model against physical measurements is presented.