Research On CAN controller conformance test system

Controller area network (CAN) is one of the most popular field buses applied in vehicle. For the CAN modules in one vehicle could come from different suppliers, the interoperability of them becomes a question. Though there is a common standard to guide the module design and production, different manufactures could have different interpretations. So a common conformance test is needed before the modules equipped in the vehicle to ensure their design meet the standard requirements and capability to work together. A CAN module is usually composed of three parts: the MCU, the CAN controller and the CAN transceiver. The controller is the main part to realize the CAN communication mechanism. According to ISO 9646, the protocol test should use a hierarchical structure, so a complete CAN conformance test may deal with three layers in OSI reference module. Each layer should be tested separately. In a CAN module, the controller implements the most tasks on DLL (data link layer). Thus, the conformance test on DLL layer of CAN is mainly test the CAN controller. This paper especially focuses on the CAN controller conformance test, which is designed to a hierarchical and black-box test. The test method and test cases are introduced at first. Then a CAN controller conformance test system is designed. The main structure and the test procedure are also described. A single elementary test is also shown up at last to give a more intuitive feeling.