TCP/IP Implementation And Optimization Based On F2812DSP

With the success of the Internet, the TCP/IP protocol stack has become a global standard for communication. TCP/IP is the underlying protocol used for web page transfers, e-mail transmissions, file transfers and etc. For embedded systems, being able to run TCP/IP makes it possible to connect the system directly to the global Internet.This paper uses TI's F2812DSP as the controller of the embedded system. The chip has both digital signal processing capabilities, but also has strong management capabilities and embedded control functions. With the expansion of the ethernet controller Ax88796 through F2812DSP's external interface and the transplantation of the TCP/IP protocol stack, we achieved communication solutions of the system. This scheme is powerful, versatile, and provides a good reference for communication solutions of other embedded systems.In the aspect of Ax88796 driver developmemt, reading and writing timing of Ax88796 are analyzed. Timing match design according to F2812DSP's external interface timing is also implemented. Ethernet frame can be sent and received by using the interrupt way.All of this hides the details of lower hardware for upper protocols. The overflow process of Ax88796 is handled and network's link status is checked by using the timer. If anything wrong, the system is restored. The system has good fault-tolerant and self-healing ability.In the aspect of the transplantation of the TCP/IP protocol stack,this paper uses the open-source embedded protocol stack uip1.0. Through cutting and transplantation, we implement the IP,ARP,ICMP and TCP protocols. We optimize the protocol stack and program the checksum calculation using assembly language. Based on PC's TCP software tesing tools and the network protocol analysis tool Sniffer,we implement strict tests for ARP,the ICMP Ping function,TCP connection, release and data transmission. Test results show that the protocols we have implemented run stably and reliably,have essential features of the TCP/IP stack ,and can seamlessly connect to the Internet.