【導(dǎo)讀】電子信息工程技術(shù)專業(yè)畢業(yè)論文--數(shù)字化語音存儲與。組成以及系統(tǒng)軟硬件的設(shè)計該系統(tǒng)的基本原理是對語音信號的錄制和回放的數(shù)。該系統(tǒng)以AT89C52單片機為微處理器實現(xiàn)對系統(tǒng)的控制以及數(shù)據(jù)的處理系。統(tǒng)采用閃存28F512作為外部數(shù)據(jù)存儲器來存放語音數(shù)據(jù)以滿足能夠較長時間存。儲語音信息語音采集部分采用ADC0809進行模數(shù)轉(zhuǎn)換語音回放部分采用DAC0832. 實現(xiàn)數(shù)模轉(zhuǎn)換并通過鍵盤等接口電路實現(xiàn)人機交互單片機工作在中斷查詢模式。能夠快速響應(yīng)按鍵要求以控制信號的采集存儲和回放等同時外圍電路輔以帶通。濾波器和增益功率放大等電路對信號進行濾波放大以保證信息的高質(zhì)量存儲與。12課題研究的意義1. 13數(shù)字化處理的前景1. 14課題任務(wù)要求2. 15本文的主要內(nèi)容3. 2系統(tǒng)總體方案設(shè)計4. 32放大器的設(shè)計7. 35采樣保持電路15. DAC0832內(nèi)部結(jié)構(gòu)及引腳16. 37AD轉(zhuǎn)換電路設(shè)計18. AD轉(zhuǎn)換的常用方法18. ADC0809的主要特性和結(jié)構(gòu)18. ADC0809管腳功能及定義19. 39存儲器的選取23. 級輸出通道由帶通濾波器后級放大電路組成

　　

【正文】 DAC digital to analog converter to convert the signal back to analog form The following diagram shows the basic setup of such a system Unit refers to the input signals used to filter hardware or software If the filter input output signals are separated they are bound to respond to the impact of the Unit is separated such as digital filters filter definition Digital filter function which was to import sequences X transformation into export operations through a series Y According to figures filter function 24hour live response characteristics digital filters can be divided into two namely unlimited long live long live the corresponding IIR filter and the limited response to FIR filters IIR filters have the advantage of the digital filter design can use simulation results and simulation filter design of a large number of tables may facilitate simple It is the shortings of the nonlinear phase Linear phase if required will use the entire work phasecorrection Image processing and transmission of data collection is required with linear phase filters identity And FIR linear phase digital filter to achieve but an arbitrary margin characteristics Impact from the digital filter response of the units can be divided into two broad categories the impact of the limited response FIR filters and unlimited number of shocks to IIR digital filters FIR filters can be strictly linear phase but because the system FIR filter function extremity fixed at the original point it can only use the higher number of bands to achieve their high selectivity for the same filter design indicators FIR filter called band than a few highIIR 510 times the cost is higher Signal delay is also larger But if the same linear phase IIR filters must be workwide calibration phase the same section also increase the number of filters and work plexity FIR filters can be used to achieve nonDigui way not in a limited precision of a shock and into the homes and quantitative factors of uncertainty arising from the impact of errors than IIR filter small number and FIR filter can be used FFT algorithms the putational speed But unlike IIR filter can filter through the simulation results there is no readymade formula FIR filter must use puteraided design software such as MATLAB to calculate So a broader application of FIR filters and IIR filters are not very strict requirements on occasions Unit from subfunctions can be divided into the following four categories 1 Lowfilter LPF 2 highfilter HPF 3 beltfilter BPF 4 to prevent filter BSF 2 Digital filter design Digital filter design must go through three steps 1 Identification of indicators In the design of a filter there must be some indicators These indicators should be determined on the basis of the application In many practical applications digital filters are often used to achieve the frequency operation Therefore indicators in the form of general jurisdiction given frequency range and phase response Margins key indicators given in two ways The first is absolute indicators It provides a function to respond to the demands of the general application of FIR filter design The second indicator is the relative indicators Its value in the form of answers to decibels In engineering practice the most popular of such indicators For phase response indicators forms usually in the hope that the system with a linear phase frequency bands human Using linear phase filter design with the following response to the indicators strengths① it only contains a few algorithms no plural operations② there is delay distortion only a fixed amount of delay ③ the filter length N number of bands for N1 the volume calculation for N2 magnitude 2 Model approach Once identified indicators can use a previous study of the basic principles and relationships a filter model to be closer to the target system 3 Achieved the results of the above two filters usually by differential equations system function or pulse response to describe 3 Application and Development of the singlechip The singlechip is one kind of integrated circuit chip which uses the ultra largescale technology and has the datahandling capacity for example arithmetic operation logic operation data transfer interrupt processing the microprocessor CPU random access datacarrier storage RAM readonly program memory ROM input output circuit IO possibly also includes fixed time the counter serial passes unguardedly SCI demonstration actuation electric circuit LCD or LED actuation electric circuit pulseduration modulation electric circuit PWM simulation multichannel switch and AElectric circuit and so on D switch integrates to together the monolith chip on constitutes to be smallest the puter system which however consummates These electric circuits can under the software control accurate be rapid highly effective plete the procedure designer preset the duty From this looked that singlechip has the function which the microprocessor does not have it may alone plete the intellectualization control function which the modern industry control requests this is singlechip biggest characteristic However singlechip also is different with the single trigger the chip before the development it only has the function greatly strengthened ultra large scale integrated circuit if entrusts with it the specific procedure it then is youngest the integrity microputer control system it PC machine has the essential difference with the single trigger or the personal puting singlechip application belongs to the chip level application needs the user to understand singlechip chip the structure and the mand system as well as other integrated circuit application technologies and the system design need theory and technology with such specific chip d