【作者】 宋鸣；

【导师】 汪辉；

【作者基本信息】 上海交通大学 ， 软件工程， 2007， 硕士

【摘要】 MAC层是嵌入式网络微处理器的关键单元之一,而MAC层的速度很大程度上受制于FCS域的计算速度即CRC32编解码器的速度,因此如何提高CRC32编解码器的速度是提高网络微处理器速度的关键。文中首先介绍了MAC层结构,并逐步引导出了MAC帧中FCS域的运算。然后介绍了CRC32算法的原理。并从最基本的串行实现开始,阐述了各种实现方法的原理和优缺点,分析了CRC32运算过程中影响运算速度的瓶颈。最后提出了用流水线结构与代入法相结合的CRC32编解码器的整体架构,电路实现方式和通过取反运算来简化CRC32解码器结构的设计方法。更多还原

【Abstract】 There is no doubt that ethernet has been a popular communication method because it is easy to use,has low cost and high bandwidth,also has high stablity ,good compatibility and high security.network function has been regarded as a main system function development target in more and more embedded system.To MAC,which performs as a platform of media access management, how to solve the problem of huge amount data checkout, has always been a difficulty for data transfer.This paper tries to find a better solution of designing CRC32 algorithm of MAC for Embedded Ethernet Microprocessor. It uses a TOP to Bottom method, tries three ways as Matrix, replacement and pipeline.And based on way of pipeline it give out a realization of specific programs.更多还原