The Research And Design Of Microcomputer Relay Protective Device Based On Embedded Ethernet

With the rapid development of embedded system, as well as the increasing matureness and widespread of network technology, networked embedded systems are widely used. The study on embedded system and its linkage to Internet are of importance in technology and economy. The Internet is based on the Ethernet technology. This is a destination of combining Embedded System and Ethernet, which used in industrial field.The paper introduce a new kind of microcomputer relay protective device with embedded Ethernet interface.The relay protective device bases on 32-bit ARM microprocessor LPC 2292. Producted by Philips,the hardware system taking LPC2292 as the core is built.The development of embeded Ethernet interface uses RTL8019AS as the Ethernet controller.Analyzed the principle of Ethernet, by setting and accessing 8019AS's intern registers. The scheme of combining efficient ARM and Ethernet controller 8019 to realize data transferring in network are adopted. The circuit interface between ARM and 8019AS is depicted in detail.In software design,Ethernet driveling program mainly deal encapsulation of Ethernet frames to be transferred,received data packets, shielded bottom hardware detail from top software;the paper analyzes the construction of embedded TCP/IP protocol, the content of each protocol. Because a completed TCP/IP protocol is too large to transplant to the embedded system. we implement a fundamental TCP/IP protocol,including IP protocol, ARP protocol, UDP protocol.