基于单片机的MP3播放器的设计

基于单片机的MP3播放器的设计(任务书,开题报告,外文翻译,论文12000字)
摘 要
    MP3是对音频进行压缩的一种技术，英文名称是MPEG Ⅰ/Ⅱ audio layer3，使用较普遍的名称是MP3。MP3压缩技术可以大幅度将音频进行压缩，压缩比可以达到1：10甚至1:12。而在如此高的压缩比下，普通用户甚至感觉不到其播放品质与CD播放品质的差别。MP3有如此高的压缩率，并且播放品质受损很小，实现了在保证播放品质的前提下，将音频数据压缩成较小的文件，极大地节省了存储空间。现在的MP3播放主要有嵌入式设备中的MP3模块，PC上的软件MP3播放器等。本设计是实现了基于51单片机的专用MP3播放器。
    单片机出现于20世纪70年代初，至今经过近半个世纪的发展，极大推动了半导体行业的发展。单片机顾名思义，即单片的，微型的计算机。所谓单片，即是将计算机系统中所必需的模块集成到一片半导体芯片上。主要集成以下模块：具有数据处理能力的CPU，数据存储器RAM，程序存储器ROM、输入输出I/O和定时计数器等。所谓微型，是因为采用了超大规模集成电路技术，将所有模块集成到很小的一块芯片上。同时，单片机是一个简单的计算机系统，通过对外围电路的扩展设计，开发者可以实现自己的小型计算机系统。
本文设计了一款基于51单片机的MP3播放器。处理器芯片采用了ATMEL公司生产的AT89C51SND1C芯片，该芯片是ATMEL公司专门针对MP3和音频设备开发而设计的一款芯片，是本设计的核心部分。本文通过阐述设计中主要用到的几项技术——USB通信协议、FAT文件系统、MP3文件格式，对本设计的基本原理进行了分析，之后详细讲解了本设计的硬件设计原理与各模块分析、系统软件结构和各模块设计。本设计采用了Altium Designer软件进行原理图和PCB的绘制，使用了Keil软件对软件设计中的U盘程序设计、MP3文件播放程序和按键控制程序进行了编写，通过串口烧写如单片机进行调试，实现了MP3文件的播放与解码。实验结果表明，本设计达到了设计所需要求，具有一定的使用价值，为后续的嵌入式开发打下了基础。

关键词：单片机，MP3，AT89C51SND1C，USB，FAT
ABSTRACT
    MP3 is a technique to compress the audio, English name is MPEG 1 / 2 Audio layer3, use the name more commonly MP3.MP3 compression technology can greatly be audio compression, the compression ratio can reach 1:10 or even 1:12. in such a high compression ratio, even ordinary users do not feel the quality of play with CD playback quality difference. Because MP3 has such a high compression rate, and the play quality loss is very small, achieved under the premise of ensuring the quality of playback, the audio data will be compressed into smaller files, greatly saves storage space. Now MP3 play mainly MP3 module in embedded equipment, PC the MP3 player software. This design is to achieve a dedicated MP3 player based on 51 single chip microcomputer.
    SCM has appeared in the early 1970s, after nearly half a century of development, has greatly promoted the development of the semiconductor industry. SCM as the name implies, namely monolithic, micro computer. The so-called monolithic, is necessary in a computer system module integrated into a semiconductor chip. Mainly integrates the following modules: data processing ability the CPU program memory data memory RAM, ROM, I/O input and output, timing counter. The miniature, is because of the large scale integrated circuit technology, all modules are integrated into a chip is very small. At the same time, the MCU is a simple computer system, through the expansion and design of peripheral circuits. Developers can implement small computer system of their own.
This paper introduces the design of a microcontroller based on the 51 MP3 player. The processor chip adopts AT89C51SND1C chip produced by ATMEL company, the chip is ATMEL MP3 and audio equipment company specializing in the design and development of a chip, is the key part of the design. This paper describes the design of several technology is mainly used in the USB communication protocol, FAT file system, MP3 file format, the basic principle of the design is analyzed, after detailed analysis of the design principle and hardware design of each module, the software structure of the system and the design of each module. This design adopts Altium Designer software to draw the principle diagram and PCB, using the software of Keil U programming in the software design, MP3 file procedures, key control procedures for the preparation, such as through the serial programmer debugging MCU, to achieve the MP3 file playback and decoding The experimental results show that this design has reached the requirements of the design, has a certain use value for the follow-up of embedded development and lay the foundation.

KEY WORDS : Single chip,MP3,AT89C51SND1C,USB,FAT 
目　录
第1章 绪论    1
1.1课题研究背景和意义    1
1.2 国内外研究现状    3
1.3研究的主要内容    4
第2章 设计方案    6
2.1设计方案选择    6
2.2选定最终设计方案    6
2.3 本章小结    6
第3章 设计方案相关技术    7
3.1 USB通信协议    7
3.1.1 USB接口结构    7
3.1.2 端点与传输类型    7
3.1.3 USB2.0通信过程    8
3.2 FAT文件系统    9
3.3 MP3文件格式    11
3.4 本章小结    11
第4章 MP3系统硬件设计    12
4.1 MP3系统硬件设计的原则    12
4.3 调试接口电路    15
4.4 Flash存储系统    15
4.5电源系统部分    16
4.6音频和功率放大电路    17
4.7 MP3的原理图和PCB图    18
4.8 本章小结    20
第5章 MP3系统软件设计    21
5.1 U盘存储程序设计    22
5.1.1 控制端口中断处理    23
5.1.2 BULK IN中断处理    23
5.1.3 BULK OUT中断处理    24
5.2 MP3播放功能模块    24
5.2.1 MP3播放器初始化    25
5.2.2 文件系统操作    25
5.2.3 MP3播放器设置    25
5.2.4 按键中断处理    25
5.3 本章小结    26
总结与展望    27
致　谢    28
参考文献    29