The design and implementation of a general ethernet interface for embedded system
FU Chong~1, CHEN Ying~2, MA Xi-min~2, ZHANG Yong-yuan~2(1. School of Information Science & Engineering, Northeastern University, Shenyang 110004, China;2. Computer Department, Liaoning Economic Professional Technology College, Shenyang 110036, China)
In this paper, a design and implementation scheme of a general embedded system Ethernet interface is proposed based on AT90S8515 single chip that uses RISC technology and RTL-8139 network interface controller hardware platform. The design aims at the characteristics that the embedded system only has limited resources. The logic structure, operation principle, DMA controller data sending / receiving principles of RTL-8139 NIC and Ether frame encapsulation course have been explained in detail. The register programming process of NIC initializing, data frame receiving and dispatching, operation of local/remote DMA controller have been deeply discussed, providing a completed implementation scheme of sending/receiving an Ethernet frame.