The Design Of Network Transfer Module Of Embedded Camera

In recent years, with the rapid development of computer technology and communication technology especially the widely available Internet and the 3C(computer,compunicate,consume electric) united as one, being micro and special become new trend and embedded products become the mainstream of information property. At the same time, the wide application of digital video techniques requires more active adaptability in user requirement. This thesis mainly discusses the key techniques of embedded network video server based on the author's work on embedded network video server in Sichuan wisesoft co.,ltd. The main content is as follows: 1. the design summarize of the embedded system. The first part of this thesis ntroduces the hardware and software design method and debug method of the system which takes ARM micro processing Linux as the OS. 2. the hardware design of the network transmission system. The proposal is to adopt AT91RM9200 as the micro processing chip, using the 100M Ethernet controller EMAC in the chip and control chip DM9161 in physical layer to realize the hardware support of network transmission. To facilitate the debugging the author designs associated periphery circuit. To satisfy the requirement of local storage later on the author designs USB circuit. 3. the design of Boot program of network transmission system and the load of Linux OS. The hardware design adopts in-chip activate mode, the activate process is let the loader program in chip load the load program RomBootloader which is custom-built and load U_boot program by which Linux OS is loaded. The design process of RomBootloader is exposed in detail in this thesis. This thesis also briefly introduces U_boot and the load of Linux OS. 4. the write of network driver program in Linux OS. The design of network device driver program based on AT91RM9200 is the most important part of the network transmission of this system. This thesis introduces in detail the data structure net_device and sk_buffin in Linux kernel which relates to the network device driver program. At the same time this thesis gives a detail design process of the control of EMAC which integrated in physical layer control chip DM9161 and AT91RM9200. The research results above has been applied in the embedded network video camera transmission system. The practice proves that the processing method mentioned in this thesis is feasible and the network video camera has good social and economical benefits.