【正文】 調(diào)節(jié)電阻 RC，其典型值是 300 千歐；時(shí)鐘頻率隨 RC值上升而下降； EOC ： 轉(zhuǎn)換結(jié)束狀態(tài)輸出線(xiàn)。把代碼狀態(tài)的特定含義“翻譯”出來(lái)的過(guò)程叫做譯碼，實(shí)現(xiàn)譯碼操作的電路叫做譯碼器。 74LS154 及其接口電路 如圖 24，引腳 G G2 接低電平，芯片工作。 G 引腳接低電平， DIR 腳可接高電平或低電平。 表 三態(tài)輸出八總線(xiàn)收發(fā)器 功能表 74LS245 引腳圖 74LS245接口電路 如圖 24所示，在本系統(tǒng)中該芯片 G引腳接低電平， DIR引腳接高電平，實(shí)現(xiàn) A數(shù)據(jù)向 B總線(xiàn)傳送的功能。 1. 匯編語(yǔ)言的特點(diǎn) 匯編語(yǔ)言有如下特點(diǎn)： ? 助記符和指令一一對(duì)應(yīng)，所以用匯編語(yǔ)言編寫(xiě)的程序效率高，占用存儲(chǔ)空間小，運(yùn)行速度快，因此匯編語(yǔ)言能編寫(xiě)出最優(yōu)化的程序。 ? 匯編語(yǔ)言缺乏通用性，程序不易移植，各種計(jì)算機(jī)都有自己的匯編語(yǔ)言，不用匯編語(yǔ)言的計(jì)算機(jī)之間不能通用。有關(guān)標(biāo)號(hào)的規(guī)定如下： 標(biāo)號(hào)是由 1~8 個(gè) ASCII 字符組成，但頭一個(gè)字符必須是字母，其余字符可以是字母、數(shù)字或其它特定字符。 一語(yǔ)句可以有標(biāo)號(hào)，也可以沒(méi)有標(biāo)號(hào)，標(biāo)號(hào)的有無(wú)取決于本程序中的 其它語(yǔ)句是否需要訪(fǎng)問(wèn)這條語(yǔ)句。 MCS51 的操作數(shù)可能有寄存器、直接、間接等 7 種不同的尋址方式。 5. 分界符（分隔符） 分界符用于把語(yǔ)句格式中的各部分隔開(kāi)，以便于區(qū)分，包括空格、冒號(hào)、分號(hào)或逗號(hào)等多種符號(hào)。 設(shè)計(jì)人員必須對(duì)所使用的單片機(jī)的硬件結(jié)構(gòu)有較為詳細(xì)的了解，特別是對(duì)各類(lèi)寄存器、端口、定時(shí)器 /計(jì)數(shù)器、中斷等內(nèi)容更應(yīng)了如指掌，以便在程序設(shè)計(jì)中熟練使用。主程序單片機(jī)檢測(cè)鍵盤(pán)，檢測(cè)到后分別執(zhí)行相應(yīng)程序，主要是上、下限的設(shè)置，及相對(duì)應(yīng)的光柱顯示和 LED 指示。 第二個(gè)循環(huán)給 P2 覆前一循環(huán)后的 A的值，即選中商加 1 的 C，給 P0覆“ 00000001” ~“ 10000000”，以余數(shù)為循環(huán)次數(shù)。它可用于各類(lèi)模擬輸入信號(hào)定量和定性的顯示。 ：采用匯編語(yǔ)言設(shè)計(jì)。 致 謝 本文的研究工作是在于慶豐老師的精心指導(dǎo)和悉心關(guān)懷下完成的，在我的學(xué)業(yè)和論文的研究工作中無(wú)不傾注著指導(dǎo)老師辛勤的汗水和心血。 感謝和我一起學(xué)習(xí)潘偉英、張登輝、徐國(guó)祥、方建良、王建飛等同學(xué)給予的關(guān)心和幫助。80s. We sat on the back of pickup trucks for hours. The sky was blue, and we couldn39。s performers of the troupe still tour the region39。s Liaoning province, decades ago. The solider gave the old man a handmade saddle when they bid farewell. The story inspired Nasun to write Carved Saddle, a song that later became one of his most popular numbers. Now, every year, Nasun recruits young singers and dancers for the troupe. The troupe has also designed a new repertoire, which is mostly based on the daily lives of Mongolian people, especially the lives of nomadic families, and has bined contemporary musical elements with folk songs of the region. Haimu, a 25yearold khoomei (a local variant of overtone singing) singer, joined the troupe three years ago. Along with a sixmember band, he performs fast songs and soft ones that he writes－ all while playing the horsehead fiddle.Although I learned the piano since childhood and grew up listening to various kinds of music, to me, the folk music of Inner Mongolia is the root, he says. Performing in remote villages is pleasant. I feel at home on the boundless grasslands, and the warm people there make me feel fulfilled. The first round of spring auction season in Beijing ended last week, but it failed to create much spring in the art market. Although two pieces of Chinese painting fetched more than 100 million yuan, the decline in trading volume and sa le rate showed a downturn this year. In the ―Grand View: Chinese Painting Highlight‖ session at China Guardian 2021 spring auctions, Pan Tianshou’s representative work Eagle, Rock and Flora hit a record auction price of 279 million yuan, while Li Keran’s masterwork Jinggang Mountain fetched million yuan, an unexpected high in recent years. However, the trading volume fells to billion yuan from billion yuan in the same period the year before. The Huangchen 2021 Spring Auctions, which recorded million yuan in total sales, experienced the same. The section number went down to 5 from 12 pared to last year. According to expert Shao Jianwu, the art market did not attract much excitement this year due to the booming stock market and the persistent problems of fery and fake deals. The two pieces of Chinese painting notched up high price this spring due to their own value not due to a revival in the market. The successful transaction of two works with a hammer price of more than 100 million yuan once again confirms that valuable and rare works of high quality always earn the longlasting high price. Chinese painting and calligraphy is still the pillar of the market. However, the overall sales rate has dropped slightly, which reflects the demand for the ordinary auction goods has weakened,‖ said the president of China Guardian’s Hu Yanyan. Besides, the entry of new buyers also makes certain changes to the direction of purchasing. In a word, the overall market trend is very unpredictable. Although China Guardian 2021 Spring Auctions has achieved remarkable results, it does not mean that the market has walked out of the predicament. We still have to wait for the big economic boom to invigorate the art market.‖ Even so, the hot pursuit of some special items appeared this spring. A special session of China Guardian Spring Auctions titled ―Fine Gilt—Bronze Buddhist Images‖ achieved a great deal with total sales volume of million yuan and 92 percent sale rate. The 5th Shamar Rinpoche Statue from 1617th century of Tibet was sold for million yuan. The Beijing Chengxuan Auctions featured almost 2,800 items of coins and stamps in three sessions with good sale rate. The Huachen Auctions also set a special session of photographs under the condition of largescale decline of auction sessions. There was a palpable dull thud of disappointment that acpanied the return of the imperial entourage of Zhen Huan to her homeland. It followed a couple years of hushed excitement as Chinese fans were fed tidbits about their proud concubine who was supposed to conquer the high ground of the North American market. Zhen Huan is, of course, the title character of The Legend of Zhen Huan, a 2021 television series that swept China off its feet and later took other Asian countries by storm. Two years ago, it was reported that HBO, a premium cable service headquartered in the United States, was going to air it in North America after some modification. Now, a condensed version that provides English subtitles but no dubbing has finally been made available on Netflix for online streaming. This version, highly anticipated as a mile