基于ISD4004语音数据的采集与播报-翻译

学号：200712020119HEBEI UNITED UNIVERSITY毕业设计翻译（汉译英）学生姓名：程英杰专业班级：07通信1班学院：信息工程学院指导教师：张涛2011年06月08日原文一、综述20世纪末，电子技术获得了飞速的发展。

在其推动下，现代电子产品几乎渗透到了社会的各个领域，有力的推动和提高了社会生产力的发展和现代信息化程度，同时也使电子产品性能进一步提升，更新换代的节奏也越来越快。

而随着我国经济建设的迅猛发展，公安、铁路、民航、金融等部门对语音记录的需求不断增长。

把语音生成技术用于工业监控系统、自动应答系统、多媒体查询系统、智能化仪表、办公自动化系统或家用电气产品中，使它们具有语音输出功能，能在适当的时候用语音实时报告系统的工作状态、警告信息、提示信息或相关的解释说明等，无疑在提高人机通信能力、减少对错误处理的遗漏、提高系统安全性能、降低人们的工作强度等方面都有极大的好处。

本设计即是出于这样目的来进行研究开发。

二、硬件设计电子录放系统可以采用PC机和嵌入式系统两种实现方式。

当使用PC机的时候，由于它的体积庞大，耗电高，造价也高，并且在某些情况下系统的稳定性得不到保证，所以用PC机实现电子录放系统，就受到了一定的限制。

而嵌入式系统体积小，供电方便，造价低，稳定性也高，所以得到了广泛的应用。

现阶段下，实现嵌入式电子录放系统主要有三种方案：通用单片机方案、DSP芯片方案和语音芯片方案。

本设计选择语音芯片方案研究。

1、语音芯片方案结构模型采用语音芯片方案实现电子录放系统，结构模型如图1所示。

图1 语音芯片方案结构模型在本方案中，控制器是整个系统的控制中心，它控制语音芯片完成特定的操作。

语音芯片是整个系统的语音数据处理中心。

录音时，语音信号经过放大后送入语音芯片进行处理，处理后的语音数据存入芯片内部存储器中；回放时，从存储器中读取语音数据，经过芯片处理后还原成语音信号，最后经功放放大后从喇叭输出。

2、语音芯片本设计选择ISD4004-16语音芯片进行研究。

ISD4004-16是美国的ISD公司推出的产品。

该芯片采用CMOS技术，内含晶体振荡器、防混叠滤波器、平滑滤波器、自动静噪、音频功率放大器及高密度多电平闪烁存储阵列等，因此只需要很少的外围器件即可构成一个完整的电子语音录放系统。

该芯片采用多电平直接模拟存储(Chip Corder)专利技术，每个采样值直接存贮在片内闪烁存储器中，语音数据不需要A/D转换和压缩，因此没有A/D转换误差，能够非常真实、自然地再现语音、音乐、音调及效果声，避免了一般固体录音电路量化和压缩造成的量化噪声和“金属声”。

该芯片工作电压3V，工作电流25~30mA，维持电流1µA。

具有SPI串行通信接口，便于和控制器通信，单片录放时间可达16分钟，其内部语音存储器共分2400行，每行占用时间长度为400ms。

程序可任选一行作为录音、放音操作的起始地址。

分段地址范围为0000H~0960H。

3、控制器单片机以其高可靠性、高性价比、低电压、低功耗等优点得到迅猛发展和大范围推广，广泛应用于工业控制系统、数据采集系统、日常消费类产品等，利用单片机实现语音录放有很大的研究和开发价值。

本设计采用AT89C51作为控制器。

AT89C51是一种带4K字节闪存可编程可擦除只读存储器的CMOS 8位微处理器。

它采用ATMEL高密度非易失存储器制造技术制造，与工业标准的MCS-51指令集和输出管脚相兼容，用来实现整个系统的功能控制，是整个电子录放系统的控制核心。

该芯片通过自身IO口虚拟SPI接口来实现对ISD4004的录音、放音、快进等功能的控制。

本设计主要分为四个模块：控制模块、录音模块、放音模块、电压模块。

各模块实现主要功能如下。

控制模块主要包括按键电路、复位电路、时钟电路。

实现功能有录音、放音、停止等，因为AT89C51不含有SPI接口因此还要模拟SPI 接口与ISD4004-16进行通信。

录音模块实现语音信号的捕获、存储。

本设计采用驻极体话筒和晶体管相结合的方法，实现对语音信号的捕获，由ISD4004-16芯片实现对语音信号的调整和存储。

放音模块实现语音信号的播放。

ISD4004-16音频输出信号比较微弱，只能驱动5KΩ的负载，本设计采用LM386对语音信号进行放大处理，输出信号推动扬声器。

电压模块实现对ISD4004-16语音芯片供电。

单片机AT89C51工作于5V，而ISD4004-16芯片工作于3V，因此需要电压转换。

本设计采用LM317实现电压的转换。

三、软件设计根据系统要实现的功能和硬件电路设计，不难设计出本系统的软件。

软件设计同样使用模块化设计思路。

设计几个供CPU访问的的功能子函数：播放子函数、停止子函数、录音子函数、快进子函数、读取当前状态和地址子函数等。

本设计中定义两个静态全局变量：rac_addr和states。

其中rac_addr为无符号整型变量，记录当前操作地址。

states为无符号的字符变量，代表ISD4004-16状态，各位定义如图2所示。

图2 states各位定义各位功能说明如下：(1)rec(states.0)：rec=1表示ISD4004-16处于录音状态。

(2)play(states.1)：play=1表示ISD4004-16处于放音状态。

(3)ovf(states.2)：ovf=1表示ISD4004-16溢出。

(4)eom(states.3)：eom=1表示ISD4004-16到达当前语音段末尾。

(5)mc(states.4)：mc=1表示ISD4004-16处于快进状态。

电路上电后，程序首先完成系统的初始化，随后查询按键状态，系统进入待机状态。

如果有按键按下，则转去执行该按键所对应的工作程序。

按键包括放音键、录音键、快进键、停止键。

在待机状态下，如果放音键被按下，并且此时ISD4004-16没有处于录音和快进状态，则调用放音子程序，此时如果再次按下放音键，则系统停止放音。

如果系统自动停止放音，则ISD4004-16的中断引脚(25脚)会自动送一低电平信号。

在硬件电路设计中，该引脚与单片机的P3.2连接。

因此，会引起一次中断，在中断子程序中会判断触发中断的原因，如果是因为OVF触发中断，则重新设定起始地址，系统进入待机状态；如果是EOM触发中断，则更新当前地址，系统进入待机状态。

如果录音键被按下，并且此时ISD4004-16没有处于放音状态，则调用录音子程序，此时如果再次按下录音键，则系统停止录音，也可以不做任何操作，直到遇到OVF，自动停止录音。

如果是快进键被按下，并且此时系统处于放音状态，则调用快进子程序，从当前地址开始快进，直到遇到EOM后停止。

如果停止键被按下，则调用停止子程序，停止当前操作并掉电。

译文I. SummaryAt the end of 20th century, electronic technology has obtained a rapid development. In support of it, almost modern electronic products have penetrated into all areas of society, it effectively promotes and enhances the development of social productive forces and the extent of modern information technology, at the same time it improves the performance of electronic products, replacement of electronic products are getting faster and faster. With the rapid development of economic construction in China, Public security, railway, civil aviation, finance and other departments frequently use the voice recording. The speech generation technology for industrial monitoring systems, automatic answering systems, multimedia query systems, intelligent instrumentation, office automation systems or home electrical products make them with speech output capabilities, which can in due course, real-time report system with work status, alerts, tips or related explanation, etc. It is no doubt improve the ability of human-machine communication, reduce the omission of error handling, improve system security, reduce the intensity of people's work have great benefits. This design is to research for such purposes.II. Hardware DesignPC and embedded systems can be used to achieve electronic recording system. If you use a PC machine, because of its large size, high power consumption, high prices, and in some cases, system stability can not be guaranteed, so electronic recording and playback system based on PC is limited. Due to the small size, supply convenient, low cost, high stability of embedded systems, it has won a wide range of application. Under the present stage, realization of embedded electronic recording system has three main programmes: General SCM programme, DSP chips programme and voice chip programme. This design selects the voice chip programme.1. V oice chip programme structure modelThe structure model of electronic recording systems using voice chip is shown in Figure 1.Figure 1 Structural model of voice chip programIn this design, the controller is the control center of the whole system. It controls the voice chip to complete a specific operation. V oice chip is the data processing center of the whole system. When you record, speech signal after amplification will be processed in the voice chip, voice data which is processed will be stored in the memory chip. When you play, voice data will be read from memory, and then voice chip will process the voice data into voice signals. Finally, voice signals output from the speaker after through the amplifier.2. V oice ChipThis design choices voice chip ISD4004-16. ISD4004-16 is produced by the United States ISD Company. The CMOS-based devices include an on-chip oscillator, antialiasing filter, smoothing filter, AutoMute feature, audio amplifier, and high density, multilevel Flash storage array. Therefore, only very few external components are needed to form a complete electronic voice recording system. The chip uses multi-level direct analog storage (Chip Corder) patented technology. The speech samples are stored directly into on-chip nonvolatile memory without the digitization and compression associated with other solutions. Direct analog storage provides a natural sounding reproduction of voice, music, tones, and sound effects not available with most solid-state solutions. The ISD4004-16 ChipCorder Product provides high-quality, 3-volt, single chip record/playback solutions for 16 minute messaging applications. Operating current 25 ~ 30mA, Standby current 1µA. SPI interface is provided for ISD4004 control and addressing functions. Its internal voice memory consists of 2,400 rows, each row takes time 400ms. Program can choose a row as recording, playback start address of the operation. The range of segment addresses for 0000H~0960H.3. ControllerSCM (single-chip microcomputer) with its high reliability, high performance, low-voltage, low power consumption advantages is rapid development and wide promotion, it is widely used in industrial control systems, data collection systems, consumer products, etc, using it for voice recorders have great value in research and development. This design uses AT89C51 as the controller. The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K bytes of Flash Programmable and Erasable Read Only Memory. The device is manufactured using Atmel's high density nonvolatile memory technology and is compatible with theindustry standard MCS-51 instruction set and pinout. It is used to control the whole system functions. It is the control center of the electronic recording system. The chip through its IO ports simulates SPI interfaces to implementation on the ISD4004 features such as recording, playback, fast forward control.This design can be divided into four modules: Control module, Recording module, Playback module, V oltage module. Main functions of each module are shown as follows. Control module includes press circuit, reset circuit, clock circuit. It implements the recording, playback, stop, etc. Because there is no SPI interface, AT89C51 simulates SPI interface to communicate with the ISD4004-16. Recording module is used to capture, store voice signals, this design combines the electret microphone and transistors to capture the speech signal. ISD4004-16 is used to adjust and store the voice signals. Playback module is used to play the voice signal. ISD4004-16's audio output signal is weak. It can drive a load as small as 5KΩ. This design uses a LM386 to amplify the voice signal, amplified signal to promote the speaker. V oltage module provides for the ISD4004-16 speech chip suitable voltage. The AT89C51 operates at 5V, The ISD4004-16 chip operates at 3V, so the voltage converter is required. This design uses a LM317 to convert the voltage.III. Software DesignAccording to the functions and hardware design of the system, it is easy to design the software. Software design also uses the modular design concept. I designed several sub-functions, which are visited by CPU: Play Function, Stop Function, Recording Function, fast forward function, read the current status and address function, etc.This design defines two static global variables: rac_addr and states. Rac_addr is an unsigned integer variable, it records the address of the current operation. States is an unsigned character variable, it represents the state of ISD4004-16, the definition of each bit as shown in Figure 2.Figure 2 Definition of each bitFunction of each bit as follows:(1) rec (states.0) : If rec is equal to 1, it said ISD4004-16 in the recording state.(2) play (states.1) : If play is equal to 1, it said ISD4004-16 in the playback state.(3) ovf (states.2) : If ovf is equal to 1, it said ISD4004-16 has an overflow.(4) eom (states.3) : If eom is equal to 1, it said ISD4004-16 has reached the endof the current voice segment.(5) mc (states.4) : If mc is equal to 1, it said ISD4004-16 in the fast-forwardstate.After power on, the program first initializes the system, and then checks the status of four key, the system enters the standby state. If one key is pressed, the system will execute the corresponding program of the key. There are four key: playback key, record key, fast forward key, stop key. In standby state, if the playback key is pressed, and the ISD4004-16 is not in the state of recording and fast forward, the system calls the playback subroutine, at this point if the playback key is pressed again, the system stops the playback. If the system automatically stops the playback, the interrupt pin (25 pin) of the ISD4004-16 will automatically send a low level signal, in the design of hardware circuit, it connected with P3.2 of SCM. Therefore, it will cause an interrupt, in the interrupt subroutine. The system will determine the cause of the interrupt. If the OVF triggers the interrupt, the system will reset the start address, and then enter the standby state; if the EOM triggers the interrupt, the system will update the current address, and then enter the standby state. If the record key is pressed, and the ISD4004-16 is not in the playback state, the system calls the recording subroutine, at this point if the record key is pressed again, the system stops the recording, you can not do anything until the OVF, the system automatically stops the recording. If the fast forward key is pressed, and the ISD4004-16 is in the playback state, the system calls the fast forward subroutine, ISD4004-16 begins to fast forward from the current address until the EOM. If the stop key is pressed, the system calls the stop subroutine. ISD4004-16 stops the current operation and powers off.。