Research Of CAN_USB Conversion System Based On FPGA

Because the Information Management Network usually use the Etheric and USB agreement, sp the research of CAN_USB agreement conversion have practical application value. Now people mostly use the PCI interface cards means to agreement conversion, however, the PCI interface cards are not easy to expand and they are very expensive, so this paper discuss the way based on FPGA to complete the CAN_USB agreement conversion.The main purpose of this paper is to complete the design of structure and to achieve the function realization. That also means to complete the RTL-level design of CAN Protocol, USB Protocol, the double FIFO in FPGA. So that make the system can pass the simulation and verification by Modelsim, and prove its feasibility and reliability.In this paper, at first we.will analyse the CAN agreement and the USB agreement. And then summarize the differences and relations between the two kinds of bus to choose the appropriate CAN controller and USB controller. Then based on FPGA chips for the hub of the system, design a complete data transmission control circuit system. Afterwards, the system will be divided into two big transmission modules which are CAN_FPGA and USB_FPGA. Through the full play of the control function and the design flexibility of FPGA, let both CAN controller and USB controller all work in slave mode. At the same time, use asynchronous FIFO(First In First Out) to achieve the two kinds of bus can complete the data storage, the data transmission and the discrimination of empty or full in different rate.After use Verilog HDL to design the each interface of the system, we will verify the reliability of the system and the realization of the function by Modelsim simulation. Finally, the system achieve the goal to produce the two-way mutual data message between CAN bus and USB bus.