【正文】 端輸入外部時鐘 (如前表所列 )。輸入時鐘的占空比無關緊要 ,因內部首先進行了分頻。 自動靜噪 (AMCAP) 當錄音信號電平下降到內部設定的某一閾值以下時 ,自動靜噪功能 使信號衰弱 ,這樣有助于養(yǎng)活無信號 (靜音 )時的噪聲。檢出的峰值電平與內部設定的閾值作比較 ,決定自動 靜噪功能的翻轉點。 1mF 的電容也影響 自動靜噪電路對信號幅度的響應速度。 SPI(串行外設接口 ) ISD4004 工作于 SPI 串行接口。協(xié)議的具體內容為： ⑴ .所有串行數(shù)據(jù)傳輸開始于 SS 下降沿。 ⑶ .數(shù)據(jù)在時鐘上升沿移入 ,在下降沿移出。 ⑸ .指令格式是 (8 位控制碼 )加 (16 位地址碼 )。 ⑺ .使用 讀 指令使中斷狀態(tài)位移出 ISD 的 MISO 引腳時 ,控制及地址數(shù)據(jù)也應同步從 MOSI 端移入。當然 ,也允許在一 個 SPI 周期里 ,同時執(zhí)行讀狀態(tài)和開始新的操作 (即新移入的數(shù)據(jù)與器件當前的操作可以不 兼容 )。 ⑼ .所有指令都在 SS 端上升沿開始執(zhí)行。信息快進只用于放音模式。 (二 )上電順序 器件延時 TPUD(8kHz 采樣時 ,約為 25 毫秒 )后才能開始操作。 例如 ,從 00 從處發(fā)音 ,應遵循如下時序 : 1. 發(fā) POWERUP 命令 。 3. 發(fā)地址值為 00 的 SETPLAY 命令 。 器件會從此 00 地址開始放音 ,當出現(xiàn) EOM 時 ,立即中斷 ,停止放音。 2. 等待 TPUD(上電延時 )。 5. 發(fā)地址值為 00 的 SETREC 命令 。器件便從 00 地址開始錄音 ,一直到出現(xiàn) OVF(存貯器末尾 )時 ,錄音停止。利用 89C51 單 片機作為 CPU 來進行總體控制，通過語音控制電路進行各種提示語音的播放，同時 使用 LED 點陣電路進行漢字顯示，實現(xiàn)了公共汽車的語 音報站以及漢字提示的功能 . 二、畢業(yè)設計（論文）的基本要求 （一）刻苦鉆研、勇于創(chuàng)新，尊敬老師，團結合作；虛心接受教師及有關科技人員的指導。 （三）嚴格遵守紀律，因事因病離崗必須請假，否則做曠課處理，若累計曠課時間達到或超過全過程 1/4 的取消評分資格，按“不及格”處理。 填寫任務書 撰寫論文，提交初稿。 定稿，完成畢業(yè)論文。 二、畢業(yè)設計（論文）的基本要求 首先要查找相關資料，在熟悉聲控開關電路原理的基礎上將電路焊接好，并能實現(xiàn)其基本要求，滿足基本技術指標。 論文要求清晰、整潔、做到設計方案合理理論完整、分析正確、制 圖符合規(guī)定。 通過這次的課題研究我們希望在理清它的發(fā)展脈絡上進一步了解他的發(fā)明原理，將平時所學的 知識運用到實驗探索上，這對提高我們的動手能力，創(chuàng)新意識，及鍛煉自己思維活動無疑是一個莫大的幫助。 ll wait in the line for one hour to get a ticket, and another two hours at the site, to only see a tiny bit of the place due to the crowds. Last year, 428 million tourists traveled in China over the weeklong holiday in October. Traveling during this period is a matter that needs thorough preparation. If you are short on time to plan the uping Golden Week it may not be a bad idea to avoid some of the most crowded places for now. There is always a place so fascinating that everyone yearns for. Arxan is a place like this. The beauty of Arxan is everlasting regardless of the changing of four seasons. Bestowed by nature, its spectacular seasonal landscape and mountains are just beyond word. Arxan is a crucial destination for the remended travelling route, China Inner Mongolia Arxan — Hailar — Manzhouli. It is also the joint of the four prairies across the SinoMongolian border, where people gravitate towards the exotic atmosphere mixed with Chinese, Russian, and Mongolia elements. As a historic site for the Yitian Battle, Arxan still embodies the spirit of Genghis Khan. Walking into Arxan, you will be amazed by a kaleidoscope of geous colors all the year round the Spring azaleas blooming red in the snow, the Summer sea wavering blue in the breeze, the Autumn leaves painted in yellow covering volcanic traces, and the Winter woods shining white on the vast alpine snowscape. Hinggan League Arxan city is situated in the far eastern area of Inner Mongolia Autonomous Region. Its full name Haren Arxan means hot holy water in the Mongolian language. Arxan is a tourism city in the northern frontier with a blend of large forest, grand prairies, vast snowfield, heaven lake cluster, thermium, as well as volcanic cluster. It is a rare and unique ecotourism base filled with healthy sunshine, clean air and unspoiled green. Nestled close to the country39。s time for the wild fruits to ripe. The picturesque Arxan in Autumn is indeed a fairyland only exists in a dream that satisfies all your fantasies. If it rains heavily on Saturday night, some elderly Chinese will say it is because Zhinu, or the Weaving Maid, is crying on the day she met her husband Niulang, or the Cowherd, on the Milky Way. Most Chinese remember being told this romantic tragedy when they were children on Qixi, or the Seventh Night Festival, which falls on the seventh day of the seventh lunar month, which is usually in early August. This year it falls on Saturday, August 2. Folklore Story As the story goes, once there was a cowherd, Niulang, who lived with his elder brother and sisterinlaw. But she disliked and abused him, and the boy was forced to leave home with only an old cow for pany. The cow, however, was a former god who had violated imperial rules and was sent to earth in bovine form. One day the cow led Niulang to a lake where fairies took a bath on earth. Among them was Zhinu, the most beautiful fairy and a skilled seamstress. The two fell in love at first sight and were soon married. They had a son and daughter and their happy life was held up as an example for hundreds of years in China. Yet in the eyes of the Jade Emperor, the Supreme Deity in Taoism, marriage between a mortal and fairy was strictly forbidden. He ordered the heaven troop to catch Zhinu back. Niulang grew desperate when he discovered Zhinu had been taken back to heaven. Driven by Niulang39。 Festival. In this day, girls will throw a sewing needle into a bowl full of water on the night of Qixi as a test of embroidery skills. If the needle floats on top of the water instead of sinking, it proves the girl is a skilled embroiders. Single women also pray for finding a good husband in the future. And the newly married women pray to bee pregnant quickly. Tradition transformed The love story of Niulang and Zhinu, and the Qixi Festival have been handed down for generations. Yet these ancient traditions and customs are slowly dying out. Many modern Chinese, particularly youngsters, seem to know more about St Valentine39。s Day. More and more young Chinese people begin to celebrate this day in a very similar way as that in western countries. Fewer people than ever will gaze at the heavens on Saturday to pick out the two stars shining bright on either side of the Milky Way, that is, if people even know on which day Qixi falls. There are ready reminders dotted about, in the form of big ads saying Sales on Chinese Valenti