一种带优先级队列的千兆以太网MAC设计

在以太网应用越来越广泛的背景下,针对某局域网具有传输数据量大和保持部分数据实时性的特点,采用了包含两种不同优先级帧的千兆以太网方案。基于Actel FPGA设计了一种带优先级队列的千兆全双工以太网MAC(Media access control),实现千兆以太网数据帧的收发,并对高优先级数据提供实时性支持。从分析含优先级字段的MAC帧结构着手,对MAC进行了模块划分,接着重点阐述了接收控制模块、发送控制模块和优先级队列模块。最后在ModelSim平台下对整个MAC进行了仿真验证;并使用Synplify进行了综合,结果表明GMII接口部分工作频率能达到141 MHz,内部模块工作频率能达到79 MHz,满足设计要求。

Design of gigabit Ethernet MAC with priority queue

Under the background of Ethernet being widely used in different areas,a Gigabit Ethernet,which contains two priority frames,is adopted to meet the needs of high-speed data transmission and real-time requirement for higher priority data in a special local area network.In this paper,a gigabit Ethernet MAC with priority queue,based on Actel FPGA,is designed to implement receiving and transmitting link layer data and to provide real-time support.The paper first analyzes MAC frame structure,then divides the MAC into small modules,and focuses on the receiver control module,transmission control module and priority queue module.At last,the MAC is simulated under the platform of Modelsim,synthesized with the tool of Synplify.The results show that the GMII interface can work at 141MHz,the internal module can work at 79MHz,which meets the expected design requirements.