Research And Design Of Embedded USB Host Controller

With the rapid development of information technology, the Universal Serial Bus (USB) has been widely used in data communication area because it has many advantages such as high speed, many types of transfer supported, play-and-plug and expandability. Traditional USB system is consisted of the USB host controller and the USB device controller, the inconvenient of PC taking restricts the application of USB devices in mobile field. Therefore, it is necessary to research the implement of host controller in mobile field and embedded platform, which satisfies the need of mobility and portability of USB system.The SOPC on-chip programmable system and the embedded system are popular concepts in the electronic design. NiosII developed by Altera is an embedded soft-core processor using the pipeline technology, single-instruction stream of RISC. It can be embedded within the FPGA, and forms a dedicated system with user-defined logic based on the FPGA chip.USB host controller also can be embedded in embedded system with the technology of SOPC.Based on the consideration of applications, I took USB technology and embedded system technology as the theoretical basis, analyzed the working principle of USB host controller, improved its functions under the embedded environment, and designed a USB host controller which can be integrated with portable devices.(1) Based on the research of transmission theory and communication protocol in USB system, and analysis on shortages of traditional USB system, I proposed an embedded USB host controller based on NiosII.(2) I carried out detailed partition on the function module of embedded USB host controller, which includes AVALON interface module, decode module, encode module, unpacking module, packing module, control logic module, CRC module, and FIFO module. I proposed the principle and function of every module in detail, and carried out design on them using Verilog Hardware describe language.(3) I gave detailed design on embedded USB host controller driver, making it can access and control the host controller and achieving assignment of data transmission bandwidth, administration of transfer list, management of endpoint descriptor, and so on.(4) I carried out function simulation and FPGA verification of USB host controller. Experimental results show that the correctness of data transmission is correct and reliable.Experimental results show that the proposed framework of the embedded USB host controller based on NiosII can get rid of PC restriction. It is effective and feasible, which can be further developed in the future.