【正文】 4004 芯片發(fā)送指令，兩條指令之間為高電平。串行輸出（MISO）：ISD 的串行輸出端。串行時(shí)鐘（SCLK）：ISD 的時(shí)鐘輸入端，由主控制器產(chǎn)生，用于同步 MOSI 和MISO 的數(shù)據(jù)傳輸。中斷（INT）：本端為漏極開(kāi)路輸出。中斷狀態(tài)在下一個(gè) SPI 周期開(kāi)始時(shí)清除。OVF 標(biāo)志用來(lái)指示 ISD 的錄、放操作已到達(dá)存儲(chǔ)器的末尾。行地址時(shí)鐘（RAC）：漏極開(kāi)路輸出。該信號(hào)保持高電平的時(shí)間為175ms，低電平時(shí)間為 25ms。該端可用于存儲(chǔ)管理技術(shù)。同時(shí)利用單片機(jī)的 ISP（在線可編程系統(tǒng)） ，實(shí)現(xiàn)控制相對(duì)可靠、容易，所以在在單片機(jī)上添加了鍵盤(pán)控制方法。圖 37 按鍵電路圖在此次設(shè)計(jì)系統(tǒng)中，我們將存儲(chǔ)空間分成了 4 塊，也就是可以錄放四段音頻，我們分別設(shè)計(jì)了錄音功能、放音功能、數(shù)碼管提示功能。錄音鍵：當(dāng)按下此鍵時(shí)開(kāi)始錄音且數(shù)碼管顯示錄制第一段語(yǔ)音，同步計(jì)時(shí)。放音鍵：當(dāng)按下此鍵時(shí)開(kāi)始播放已經(jīng)錄的語(yǔ)音，它可以播放 4 次，分別對(duì)應(yīng)錄音時(shí)的 4 段錄音，可以自由選擇播放已經(jīng)錄得語(yǔ)音。暫停鍵：錄音結(jié)束后，開(kāi)始放音時(shí)，此鍵在放音時(shí)用處很大，當(dāng)放第一段語(yǔ)音時(shí)，在語(yǔ)音播放中按下此鍵語(yǔ)音就會(huì)停止，再按放音鍵就會(huì)播放下一段語(yǔ)音，隨時(shí)都可以轉(zhuǎn)換到下一段語(yǔ)音的播放。　顯示電路此系統(tǒng)中的顯示電路主要有 LED 燈和電子數(shù)碼管顯示電路。LED 燈顯示電路主要用于當(dāng)按下不同的按鍵時(shí)顯示不同的亮燈花樣，以便區(qū)別不同的操作，也更貼近實(shí)際的日常應(yīng)用。 圖 38　8 個(gè) LED燈2. 數(shù)碼管顯示電路主要用于顯示當(dāng)按下錄音鍵、放音鍵、暫停鍵不同的按鍵時(shí)系統(tǒng)所處的狀態(tài)和顯示當(dāng)前的電路工作在何種模式。圖 39 構(gòu)成的數(shù)碼管顯示電路原理圖本系統(tǒng)的數(shù)碼管顯示功能由 74HC138 和 74HC573 兩個(gè)芯片實(shí)現(xiàn)，其介紹如下：74HC138 譯碼器可接受 3 位二進(jìn)制加權(quán)地址輸入 A、B、C 賦值 0~7，并當(dāng)使能時(shí)，提供 8 個(gè)互斥的低 有效輸出 Y0~Y7 置 “0”，如 P2=0，則 Y0=0，P2=6，則 Y6=0，即選通第 7 個(gè)數(shù)碼管，實(shí)現(xiàn)數(shù)碼管的位選。任選一個(gè)低 有效使能輸入端 作為數(shù)據(jù)輸入，而把其余的使能輸入端 作為選通端，則 74HC138 亦可充當(dāng)一個(gè) 8 輸出多路分配器，未使用的使能輸入端 必須保持綁定在各自合適的高有 效或低 有效狀態(tài)。11 腳接 VCC，鎖存不起作用，相當(dāng)于直通，相應(yīng)的段賦值“1” 有效，需要鎖存時(shí)接單片機(jī) ，接 VCC 和 由跳帽轉(zhuǎn)換完成。當(dāng)按下錄音鍵時(shí)，錄得第幾段不同會(huì)在數(shù)碼管上顯示相應(yīng)的數(shù)字 4，當(dāng)按下放音鍵時(shí)數(shù)碼管也會(huì)顯示相應(yīng)的數(shù)字。放大器采用通用型音頻功率放大器LM386 來(lái)實(shí)現(xiàn)。圖 310　音頻放大器 LM386LM386 是美國(guó)國(guó)家半導(dǎo)體公司生產(chǎn)的音頻功率放大器，主要應(yīng)用于低電壓消費(fèi)類(lèi)產(chǎn)品。但在 1 腳和 8 腳之間增加一只外接電阻和電容，便可將電壓增益調(diào)為任意值，直至 200。 LM386 的封裝形式有塑封 8 引線雙列直插式和貼片式,且具有以下特性(Features): 靜態(tài)功耗低，約為 4mA,可用于電池供電。外圍元件少，電壓增益可調(diào)，20200 且失真度低。該系統(tǒng)的如圖 41 所示。因此，用戶(hù)發(fā)完上電指令后，必須等待 TPUD，才能發(fā)出一條操作指令。其次放音地址的計(jì)算同錄音相同，第一段地址為 0x00，第二段地址為 0x12 以此類(lèi)推。其設(shè)計(jì)流程如圖4開(kāi)始放音判斷按鍵次數(shù)？Ox01（按一下） 放音（地址 Ox00）Ox02（按兩下） 放音（地址Ox100）Ox03（按三下） 放音（地址Ox200）Ox04（按四下） 放音（地址Ox300）液晶屏顯示液晶屏顯示液晶屏顯示液晶屏顯示結(jié)束否是開(kāi)始掃描鍵值是否有鍵按下延時(shí) 10ms 消抖是否有鍵按下提取鍵值調(diào)用鍵盤(pán)處理子程序結(jié)束NNYYY圖 43　鍵盤(pán)處理流程圖第５章　結(jié)論與展望結(jié)論這次畢業(yè)設(shè)計(jì)是對(duì)四年本科學(xué)習(xí)知識(shí)的綜合應(yīng)用，通過(guò)做畢業(yè)設(shè)計(jì)，我不但對(duì)以前所學(xué)的知識(shí)加深了理解，而且提高了自己的動(dòng)手實(shí)踐能力、分析問(wèn)題和解決問(wèn)題的能力以及創(chuàng)新能力，在具體應(yīng)用當(dāng)中還培養(yǎng)了自己科學(xué)的設(shè)計(jì)思維和嚴(yán)謹(jǐn)?shù)墓ぷ髯黠L(fēng)。并具體分析了所選用方案的市場(chǎng)價(jià)值和應(yīng)用價(jià)值，同時(shí)還考慮到系統(tǒng)中一些設(shè)備成本以及學(xué)校資源方面的因素，以此確定了設(shè)計(jì)方案。這次畢業(yè)設(shè)計(jì)能夠取得成功是老師的精心指導(dǎo)和小組成員共同努力的結(jié)果。展望錄音筆對(duì)于我們現(xiàn)如今的人們己經(jīng)是再熟悉不過(guò)的產(chǎn)品了，它己經(jīng)應(yīng)用在了很多地方，其中主體部分應(yīng)該是記者了。除此之外錄音筆小巧易于攜帶，存儲(chǔ)內(nèi)容量大，基于這些優(yōu)點(diǎn)，越來(lái)越多的得到人們的青睞。設(shè)計(jì)已經(jīng)結(jié)束了，經(jīng)過(guò)了半學(xué)期的努力終于完成了本次設(shè)計(jì)，首先要感謝我的指導(dǎo)老師葛莉老師，每有問(wèn)題，老師總是耐心的解答，使我能夠充滿(mǎn)熱情的投入到畢業(yè)設(shè)計(jì)中去；還要感謝我的同學(xué)們，他們熱心的幫助，在課題的研究方向和有關(guān)書(shū)籍介紹都給了我很大的幫助，同時(shí)我也要感謝我的同組成員穆明。 附　錄附錄Ａ　外文資料原文The research and application of digital Digital voice recorderOverall DescriptionISD4004 is the ISD pany manufacturing a new voice chip. Using the voice chip ChipCorder patent technology. The chip without A/D conversion and pression can direct store, without A/D conversion errors, in A record bits (BIT) voice signal can be stored 250 level, equivalent to A/D usually record 8 times. Slice the crystal oscillator in integration, mike preamplifier, automatic gain control and so on, as long as few peripheral equipments, can form a full audio recording system. And the ISD other series pronunciation product different is, ISD4004 is a micro controller from equipment, and Lord controller can be patible with the micro controller interface SPI, also can use the I/O simulation SPI munication protocols. ISD4004 series for working voltage 3V, monolithic recording time of 8 ~ 16 minutes, timbre, suitable for mobile phones and other portable electronics. This chip adopt CMOS technology, contains the oscillator, fight aliasing filter, smoothing filter, audio amplifiers, since the action pixels and highdensity multilevel flashing storage display. All the operation must by chip microcontroller control, operation orders through serial munication interface (SPI or Microwire) into. Chip Digital voice recorder chips ISD4004 is the core part. ISD4004L16M series monolithic recording time 8 to 16 points, timbre. Chip adopt CMOS technology, contains the oscillator, microphone preamplifier, automatic gain control, prevent confusion filter, smoothing filter driver and EEPROM, speaker. The smallest recording system array microphones, horn, only two buttons, power and a few resistance capacitance. After recording operation in automatic into low power consumption, chip, low consumption 5uAe only saving pattern.ISD4004 series have only the recording controls and edge/level trigger two playback control. Unsegmented most Jane when peripheral lines, also can press for unit minimum long binations subsection, greatly improving the control flexibility chip adopt multilevel direct analogue storage patent technology, each sample direct stored in a single EEPROM unit in pieces (the very real, and can therefore reproduce music voice, natural, each effect, sampling frequency tones from to KHz, , only a faint of sound effects.Adopt AT89C52 single chip puter to realize my design. For my design speaking ISP technology can be very convenient flexible realize voice recording function of. This provides for realizing speech input the hardware conditions. Easy ISP technology is in a system programmable device to realize the pronunciation chip control. This control directly through the hardware circuit implementation ISP devices and tell the software interface program, use rise convenient and quick. ISD chips like the sound of two kinds of control ways (pin edge or level trigger control and micro controller serial munication interface control), it is easy to lose the storage of data, and the operation EEPROM convenience. This development environment support standard C language, and provides the voice recording, the C language program function, as long as the use of understanding function, can easily finish voice recording, all of these software development provided a convenient conditions. We are according to the design requirements in realizing the basis of basic recording function by AT89C52 single chip puter is muti_function integrated function expansion recording system functions. For example, use the AT89C52 single chip puter keyboard control function introduction feet add introduction digital tube or digital display functi