摘要
为了解决用户只能通过书面资料理解以太网MAC帧格式的问题,本文实现了一种基于微处理器S3C44B0X的以太网MAC帧的检测与显示方法。系统通过电压比较器将双绞线上脉冲信号转换为微处理器可识别的二进制信号,完成完整以太网MAC帧的采样与曼彻斯特编码的解码,并通过液晶将实验结果进行显示。实验表明,该方法可以捕捉到未经以太网控制器处理的完整的以太网MAC帧,并使用户通过显示液晶对MAC帧中用户无法干预的字段进行分析。
In order to solve the problem that readers can know the format of Ethernet MAC frame only from graphs on books abstractly,the method of detecting and displaying MAC frame based on microprocessor S3C44B0X is designed and realized in this paper.As the microcontroller S3C44B0X can just deal with data in the form of binary,but the data transmitted on twist are in terms of pulse signal.So this system realizes the transformation between pulse signal on twist and digital signal that microprocessor can identified by voltage comparator,and of course completes detection and Manchester-encode decoding of Ethernet MAC frame.This system would also display the MAC frame by liquid crystal display after detecting it.Experiment results show that system can catch the whole MAC frame of Ethernet including fields of preamble,Start frame delimiter and frame check sequence.The captured MAC frame will also be displayed by liquid crystal display so that users can analyze those MAC frame fields which can not be intervened by users.
出处
《电气电子教学学报》
2010年第S1期47-49,共3页
Journal of Electrical and Electronic Education
基金
国家人防办项目(2005GF149)
