Software Desiging Of Network Development Based On The Multiporteachange Ship

With IT information, network and intelligent rapid development, the embedded system technology is developing widely and becomes to the most polular technology in the information industry, which is widely applied to network communication, family consumer electronics, medical equipment, defense aviation, industry equipment control and car traffic, etc. Therefore, the development of embedded system is a hot spot in the industry technology in recent years.Based on micro processing chip LPC2387and exchange chip88e6083, this topic research focuses on software development. It includes the following several aspects:In order to realize the Ethernet function of the embedded system, I develop network driver of the target plate which integrates the micro processing chip LPC2387and exchange chip88e6083. My job includes transplanting the real-time operating system uC/OS-Ⅱ and designing simple embedded TCP/IP protocol stack, then initializing hardware of the network devices. At last test the ethernet protocol, such as ARP, ICMP, TCP.Based on the Ethernet function of the embedded system, I see the target plate as the server and the PC as the client, then I program CGI to realize interactions between the server and client. At last realize the EasyWeb server. For the sake of checking the function of the EasyWeb server, we do two test, the modification working mode of exchange chip and settings VLAN group.Take the real-time performance of the embedded system into considence, I research the zero copy technology which is based on the embedded TCP/IP protocol stack. The principle of the zero copy technology is decreasing the copy times of the data frames between ethernet cache and CPU memory. Finally through the test zero copy technology could prove that it can improve the real-time performance of the embedded system.Take practical application into considence, in order to avoid loop tank and Netstorm, I research the spanning tree protocol(STP). Spanning tree protocol works as a management protocol on the data link layer. STP can build tree topology link through exchanging BPDU message between bridges, and selectively block redundancy link so as to eliminate the loop network. The affect of STP is improving the reliability of embedded system.