【作者】 杨宗立；

【导师】 徐大诚；

【作者基本信息】 苏州大学 ， 信号与信息处理， 2007， 硕士

【摘要】 随着数码产品的不断普及,摄像头的应用范围在不断的扩大,摄像头中的核心部件----图像传感器的用量也在日益增长,由于CCD图像传感器成本等因素的限制,近几年CMOS图像传感器的用量急剧上升,大量的摄像头生产厂商都选用了CMOS图像传感器,特别是在手机等数码产品所用的摄像头中都选用了CMOS图像传感器。本文就是基于以上背景的情况下,给出了基于USB2.0接口的CMOS图像传感器视频传输系统。它可广泛应用在摄像头产品的质量检测、图像获取系统,具有传输速度快、电路简单、成本低廉和连接安装方便等特点。围绕基于USB2.0的视频传输系统,文中讨论了它的基本组成,系统的硬件、软件设计方法,并详细描述了USB2.0接口部分的原理以及在PC上视频显示的原理,给出了相关程序设计过程和部分源代码,还进行了综合测试。系统采用的主要核心部件包括Cypress公司FX2系列的CY7C68013芯片、CMOS传感器组成的摄像头等。首先根据实际的需要设计了系统的硬件电路,制作了PCB板;然后在该硬件电路的基础上,编写了系统的固件程序。固件程序设计主要包括以下几部分:(1)USB2.0接口的初始化。通过对CY7C68013的CPUCS, USBCS, IFCONFIG等寄存器进行设定,使其工作在预定的模式下;(2)图像传感器的初始化程序设计;(3)通用编程接口(GPIF)程序设计。首先FIFO读波形描述符(GPIF波形)由GPIF Designer工具产生,然后固件启动FIFO读波形,从而实现对CMOS摄像头时序的控制和图像数据采集。(4)USB2.0的批量传输程序设计;(5)主程序设计。主程序的功能除了要完成(1)～(4)中断论述的功能外,还要给出USB控制传输的固件应答程序及相应的中断初始化和中断服务程序。最后,编写了应用程序。其主要功能有:检测USB设备、设置USB数据传输管道设置,从USB接口采集数据,在PC中实时(动态)显示并能实时抓取图像,为以后在该系统的基础上对需要的图像进行分析处理奠定了基础。设计过程充分利用了现有芯片资源,在不使用CPLD等控制芯片的条件下,用GPIF接口的控制逻辑来有效合理地控制CMOS摄像头的工作时序,并读取数据至缓冲区,从而节省了一般类似系统所必需的FIFO芯片和控制时序的CPLD芯片等。综上所述,本文给出的这种设计方案是一种优化性能突出的设计方案,它不仅降低了开发成本,也节省了系统容量,更利于产品开发。通过实验,系统数据传输稳定、图像清晰。该系统已应用在CMOS数字图像传感器摄像头的质量检测系统。更多还原

【Abstract】 With the digital product being popularized, application range of the camera shooting is gradually expanded , the quantity in demand for image sensors in main component of the camera shooting is also increasing gradually, however, because of the limit of cost for CCD image sensor , the demand of CMOS image sensor is steeply rising in the past few years. The large number of producers for camera shooting has selected the CMOS image sensor, especially; camera shooting used for mobile phones and other digital products has used the CMOS image sensor. Based on the above background, the thesis plans to design the video transmission system of CMOS image sensor based on USB2.0. It can be widely applied to the system, which can detect camera shooting and capture image. And it has characteristics of high speed of transmission , circuit simplicity, low cost and facility of linking installation and so on.Based on the USB2.0 video transmission system, this thesis discusses its basic components, hardware, software design methods and a detailed description of the principle of the USB 2.0 interface and video display on PC, and it presents the program design process and part of the source code and also takes a comprehensive test.The components adopted in the system mainly include CY7C68013 of FX2 series manufactured by Cypress Semiconductor, camera shooting of CMOS sensor and so on. As for the framework of the thesis, firstly, the systematic hardware circuit are designed according to actual need and make the PCB boards. And then based on the hardware circuit, I programme the firmware procedure of system. Firmware procedure mainly includes several parts of the following: (1) USB2.0 interface’s initialization. The procedure sets the registers for CPUCS, USBCS, IFCONFIG of the CY7C68013, and makes it work in the scheduled mode. (2) Image chip’s initialization programming. (3) General Programmable Interface(GPIF) programming. First,GPIF designer are made use of to design waveform descriptors of FIFO Read(GPIF waveform ), and then it will be started up FIFO Read waveform descriptors by the firmware. So, FIFO Read waveform descriptors can control the time sequence of CMOS camera shooting and collect image data from CMOS camera shooting. (4) USB2.0 bulk transfer programming. (5) Main framework programming. The function of main program can’t only accomplish the function of the (1)～(4) interruption, but give out firmware responsion of USB control transfers and corresponding procedures of interruption initialization and interruption service. Finally, applied procedure is programmed. Its main function includes: detecting USB device, setting up USB data transmission pipe, collecting data from USB interface, displaying the video data on PC and capturing video image at any moment, so based on the system, the applied procedure lays the foundation of analyzing and processing image data later.The system design takes full advantage of the current IC resources. It controls the time sequences of CMOS sensor efficiently by using GPIF, and reads the data into the given buffer, so that the whole system is designed without FIFO and CPLD which are indispensable to the normal solutions. In conclusion, the scheme proposed in this paper has the prominent performance on optimization, which can both reduce the cost and save the resource of the system. Further more, the product development will also be very easy. The experimental results show that the transmission of the system data is stable and the image is sharp. The system has been applied in the quality detection system of the camera shooting of CMOS digital image sensor.更多还原