【作者】 高蕾； 佟为明； 刘勇；

【Author】 Gao Lei Tong Weiming Liu Yong (Harbin Institute of Technology Harbin 150001 China)

【机构】 哈尔滨工业大学 电气工程及自动化学院电气工程系；

【摘要】 目前,人们大多通过书面资料来了解以太网上传输的MAC帧格式,而没有能够捕捉到完整以太网MAC帧的方法。为了能够直观地分析完整的MAC帧格式,本文给出了基于S3C44B0X的以太网MAC帧检测系统,该系统由发送节点和接收节点组成。其中,发送节点利用以太网控制器RTL8019AS完成以太网MAC帧的构造,并将构造好的MAC帧发送两次:第一次接收时,接收节点利用RTL8019AS获取MAC帧的字节数,并根据该字节数确定MAC帧采样次数;第二次接收时,接收节点利用MAC帧检测单元从传输介质上捕捉MAC帧信号,然后将捕捉到的电平信号转换为二进制信号并进行曼彻斯特解码,最终将解码后的MAC帧通过显示液晶进行显示。实验结果显示,该系统能够捕捉到传输介质上传输的完整的以太网MAC帧,可广泛应用于以太网教学中。更多还原

【Abstract】 In order that readers can analyze the format of MAC frame intuitively,the Ethernet MAC frame catch system based on mircontroller S3C44B0X is introduced.It’s consisted of send node and receive node.The send node constructs Ethernet MAC frame and then send it two times.For the first acceptance,the receive node uses RTL8019AS to get the MAC frame’ length which is used to determine MAC frame sampling time.When the receive node gets the MAC frame for the second time,it catches Ethernet MAC frame from trasmission medium and convert them from the form of binary singal to Manchester encoding.At last,the MAC frame caught by receive node from teansmission medium shows on liquid-crystal display.Experiment results show that the MAC frame catch system can catch the integrated MAC frame which is transmitted on transmission medium,and can be widely used in Ethernet teaching.更多还原