摘 要
USB ( universal serial bus)是近年发展起来的一种快速、灵活的总线接口。它最大的特点是易于使用、可热插拔、接口连接灵活，并且能够提供外设电源，在嵌入式系统及智能仪表中得到广泛的应用。本文讨论了一种基于USB2.0的数据传输设计和实现方法。
本数据传输系统采用FPGA作为主控制器，通过SLAVE FIFO方式将数据送入USB控制板，最后经USB将数据读入计算机。论文首先简述了USB协议，包括体系结构、数据流模型、传输类型等。在硬件设计部分先讨论了USB2.0接口芯片CY7C68013，然后给出了FPGA的硬件设计方案及FPGA程序设计；在软件部分，介绍了FX2的固件框架，使用了USB从属FIFO接口模式。最后将系统的软硬件设计相结合，实现了对系统调试。
关键词：USB，CY7C68013，固件，FPGA
Abstract
USB (universal serial bus) is one kind which the recent years developed fast, the nimble bus interface. It most major characteristic is easy to use, may to insert hotly pulls out, the connection to be flexible, and can provide the peripheral device power source, obtains the widespread application in the embedded system and the intelligent measuring appliance. But 51 series monolithic integrated circuits by its superior performance, the mature technology, the high performance-to-price ratio are widely applied in observe and control automated domains and so on instrument. This paper discusses a design scheme and implementation of data-transmission system based on USB2.0.
The data transmission system used FPGA as a host controller, and send data to the USB board through SLAVE FIFO, and finally, it will be written into computer. This paper, firstly, introduces knowledge about USB protocol, including architectural overview, data flow model, data flow types and so on. In the part of hardware, the hardware design of USB communication system based on USB2.0 chip CY7C68013 is discussed and then the hardware design scheme of FPGA; In the part of software, the FX2 firmware flow is shown, and the firmware design of USB Slave FIFO is discussed in detail. Finally, combining hardware design and software design, we give the debug strategy in this system.
