语音信号处理毕业设计论文

摘要

语音信号处理属于信息科学的一个重要分支，大规模集成技术的高度发展和计算机技术的飞速前进，推动了这一技术的发展。在数字音频技术和多媒体技术迅速发展的今天，传统的磁带语音录放系统因体积大、使用不便、放音不清晰而受到了巨大挑战。本课题组提出的体积小巧，功耗低的数字化语音存储与回放系统，可以有效的解决传统的语音录放系统在电子与信息处理的使用中受到的限制。

本文提出了以SST89E554RC芯片为核心的单片机小系统，用它来实现整个数字化语音存储与回放系统的逻辑控制。单片机将通过模数转换器A/D转换的数字信号送入外部存储器中，在回放时，单片机再从存储器中读出，送到数模转换器D/A转换成模拟信号输出。系统采用了键盘选择压缩方式，在字符型显示器上显示，并可实现实时语音存储与回放，性能稳定，并且界面友好。多次的测试实验表明，本系统基本满足设计要求。

文中重点讨论了小系统的设计过程、硬件流程和软件的调试问题，研究了采用DPCM编码方式以解决因存储空间不够而引起的存储时间不够的问题。

关键字：单片机小系统；外部中断；A/D转换；D/A转换；IAP；DPCM

Abstract

V oice processing is an important branch of information science. The technology has improved a lot with the high development of the large scale integration technology and the computer science technology. As the rapid development of digital audio technology and multi-media technology, the traditional tape desk is facing challenge for it unclear replaying and inconvenient. Our design, digital voice storage and replay system, proposed the volume is exquisite, the power loss low. It can solve the limitation of the tradition voice system in electronic and information processing usage.

The article has presenting a single-chip system with SST89E554RC chip as it center processing .The MCU(microcontroller) system is used to control the logic of the digital voice storage and replay system. When the voice system is in it storage state, the MCU system will send the digital signal to the RAM from the ADC (Analog to Digital Converter). When in the state of replaying, the MCU system will read the signal from the RAM (Random Access Memory), and then, send the signals into DAC (Digital to Analog Converter). After this, the signals will change into analog signal. The system has designed the keyboard selecting compression method, LCD indicating. It can also realize the real-time storing and replaying, and the surface is very friendly. The local test indicates this system satisfied basically designing required.

The article emphasizes the designing process of the MCU system, the flow of the hardware and the debugging of software. Compression coding method, which is used to solve the limited room of the RAM, is also emphasized in it.

Keywords: MCU system; external interrupt; ADC; DAC; IAP; DPCM

目录

摘要 ................................................................ I Abstract ............................................................. II 绪论 . (1)

第1章理论基础及系统要求 (2)

1.1 引言 (2)

1.2 语音系统构成 (2)

1.2.1 系统基本原理 (2)

1.2.2 系统组成和流程 (2)

1.2.3 语音系统的要求 (3)

1.3 控制系统任务 (3)

1.4 本章小结 (4)

第2章控制系统硬件设计 (5)

2.1 引言 (5)

2.2 设计方案论证 (5)

2.2.1 采用可编程逻辑器件来实现控制 (5)

2.2.2 采用DSK来实现控制 (6)

2.2.3 采用单片机系统来实现控制 (7)

2.3 控制系统整体设计 (7)

2.4 本章小结 (8)

第3章控制系统硬件的实现 (9)

3.1 引言 (9)

3.2 单片机芯片介绍 (9)

3.3 单片机外围电路 (11)

3.3.1 存储芯片RAM62256及译码芯片74LS138 (11)

3.3.2 锁存器74HC573和收发器74HC245 (12)

3.3.3 键盘中断电路 (13)

3.3.4 RS-232串口电路 (13)