两级链表在交换控制芯片描述符管理中的应用

摘要

This paper puts forward a method to address on-chip Memory Management Unit(MMU) by hardware logic.To manage a 9 728 Byte jumbo frame's storage,two levels of linked lists are used to organize descriptor output queue table in designing a switch controller.The first level is the TXQ linked list,which is used to maintain frame priority order for each port.And the second level is the buffer tag linked list,which is used to maintain the order of the buffer pages corresponding to each frame.Simulation experimental results show that two levels of linked lists can organize descriptor effectively.%研究一种利用硬件实现片上存储器管理的方法,针对目前交换机最长至9 728 Byte的超长帧存储问题,在交换控制芯片描述符管理方法的基础上,提出一种两级链表的设计方法,即第一级发送队列链表和第二级缓存标签链表,分别用于维护每个端口的帧优先级次序及每个帧的缓存页地址.仿真实验结果证明,该设计方法能有效地管理描述符,可处理超长帧的交换控制芯片.