嵌入式多媒体终端设备关键技术研究

发布时间：2018-06-17 17:49

本文选题：嵌入式系统 + 实时时钟　；参考：《华中科技大学》2008年硕士论文

【摘要】： 随着计算机技术的发展,特别是多媒体技术的快速发展,多媒体广告机作为一种全新的广告形式逐渐渗透到人们生活的各个方面,并在广告市场中占据越来越重要的位置。为此,采用ARM+DSP双处理器平台和开源的嵌入式Linux操作系统自行开发了一套嵌入式多媒体广告机系统。多媒体广告机系统采用PCF8563作为实时时钟芯片,系统可以在I2C协议控制下访问其寄存器。由于ARM处理器EP9315并没有提供I2C接口,因此采用GPIO针脚来模拟I2C总线的数据线和时钟线,以软件方式模拟I2C协议,实现I2C总线驱动,为系统提供访问时钟芯片的接口。在此基础上设计和实现了实时时钟驱动,为应用程序提供了设置和获取系统时间的接口,并利用PCF8563的报警功能以及能够输出中断的特性,设计和实现了整点报时功能。设计了音频模块,完成音频数据在系统中的传输,并为应用程序提供控制声音播放的接口。系统采用ARM+DSP双处理器的架构,音频数据存储在ARM外接的磁盘上,而数据的解码却由DSP来处理,所以必须实现双核之间的数据通信。DSP的HPI(Host Port Interface)主机接口为外部CPU提供了访问DSP内存的方式。利用HPI驱动以共享缓冲区的方式将从ARM磁盘读出的数据发送给DSP的解码单元,经过解码处理后依次发往8个缓冲区,然后以DMA链方式发送给McASP(Multi-channel Audio Serial Port)的发送缓冲区,在位时钟和帧同步时钟控制下以I2S格式串行发送给UDA1345TS进行数模转换。ARM通过GPIO针脚模拟L3总线来控制UDA1345TS,调节音量大小,设置静音模式,初始化系统时钟频率和输入数据格式等。
[Abstract]:With the development of computer technology, especially the rapid development of multimedia technology, multimedia advertising machine as a new form of advertising gradually infiltrates into all aspects of people's lives, and occupies an increasingly important position in the advertising market. Therefore, an embedded multimedia advertisement machine system is developed by using arm DSP dual processor platform and open source embedded Linux operating system. PCF8563 is used as the real time clock chip in the multimedia advertisement machine system. The system can access the register under the control of I2C protocol. Since arm processor EP9315 does not provide I2C interface, GPIO pin is used to simulate the data line and clock line of I2C bus, and the I2C protocol is simulated by software to realize I2C bus driver, and the interface to access the clock chip is provided for the system. On this basis, the real-time clock driver is designed and implemented, which provides an interface for the application program to set and obtain the system time, and uses the alarm function of PCF8563 and the characteristic of outputting interruption to design and implement the point time reporting function. The audio module is designed to complete the transmission of audio data in the system and provide the interface for the application program to control the sound playing. The system adopts arm DSP dual-processor architecture, audio data is stored on arm external disk, while data decoding is processed by DSP. So it is necessary to realize the data communication between dual cores. The HPII-Host Port Interface (HPIPort Interface) interface of DSP provides a way for external CPU to access DSP memory. The data read out from arm disk is sent to the decoding unit of DSP by using HPI driver in the form of shared buffer. After decoding, the data is sent to 8 buffers in turn, and then sent to the sending buffer of McASPU Multi-channel Audio serial port by DMA chain mode. Under the control of bit clock and frame synchronous clock, the UDA1345TS is sent to UDA1345TS serially with I2S format. Arm controls UDA1345TSthrough GPIO pin analog L3 bus, adjusts volume, sets mute mode, initializes system clock frequency and input data format and so on.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：TN919.82

【引证文献】