说明：  ? CAN总线的特点 ? CAN总线拓扑图及其模型 ? CAN总线分层结构 ? 物理特性 ? CAN总线报文 ? 仲裁机制 ? 错误类型及处理机制 ? 总结
(CAN protocol introduction below characteristics of the CAN bus CAN bus topology and its model CAN bus layered structure physical properties CAN bus message arbitration mechanism Error types and processing mechanism summary)