Study And Implemention Of Configurable Embedded TCP/IP Protocol Stack

With the development of Internet, TCP/IP has virtually become the international standard in the communication field. If the connection, by means of embedded TCP/IP stack, between the embedded system and Intranet, even Internet can come true, the embedded system will be much more practical and bring about enormous economic benefits. Based on the research and study of the current situation of the embedded TCP/IP stack products home and abroad, independently the configurable embedded TCP/IP stack -- VIP stack has been developed. According to VIP stack, this paper expatiates on ARP,IPv4,ICMPv4,UDP,TCP and other protocols, including an analysis of protocol configuration, and also offers the implementation method of VIP stack. VIP stack, with the adoption of layered architecture, can be carried out by means of ANSI C language, strictly abiding by international RFC standard without any private protocol and any assumption, so as to ensure integrality and consistency of the protocol stack. In the aspect of design VIP stack takes full consideration of the property of transplantation. The whole VIP stack stands on top of the system abstract layer, which eliminates the differences of hardware architecture, embedded operating system and compilers.Taking the limited resources of 8-bit MCU and great disparity in clients' requirements into account, the design of VIP stack lays emphasis on the fine granularity configuration, on the one hand to make VIP stack possible to run on, and on the other hand to meet the higher requirements not only of 8-bit MCU, but also of 16-bit MCU, even of 32- bit MCU. VIP stack emphasizes not only the configuration, but also the availability. The availability of many embedded TCP/IP stack is not very good, because of its demands for the traditional and complete TCP/IP stack on another side of the communication, not the same embedded TCP/IP protocol stack just as them. Though VIP stack stresses configuration, it is not allowed to configure for those necessary functions, and strictly constrains the mechanism among the configurable functions to make sure the availability of VIP stack.In embedded system, memory is very valuable, especially for 8-bit MCU, commonly with a few hundred bytes, or a few K RAM. The unique memory management mechanism has been adopted in VIP stack to improve agility and efficiency of memory management to a greater degree.Some specific architecture is allowed to be optimized in VIP stack. In the implementation of VIP stack, macro definitions have been given to some functions, which need more time to run, and clients are permitted to perform these functions again with the adoption of assembly based on the target architecture for optimization.Now, VIP stack is comprehensively tested in x86 architecture, and results and analysis offered of each protocol.