【正文】 衷心的感謝！不積跬步何以至千里，本設(shè)計(jì)能夠順利的完成，也歸功于各位任課老師的認(rèn)真負(fù)責(zé)，使我能夠很好的掌握和運(yùn)用專業(yè)知識(shí)，并在設(shè)計(jì)中得以體現(xiàn)。 中斷接收程序流程圖如圖 32 圖 32 中斷接收程序流程圖 具體程序見附錄 3。 圖 25 顯示電 路 14 第 4 章 信息監(jiān)測(cè)系統(tǒng)的軟件設(shè)計(jì) 初始化程序 將 P0～ P3端口置輸入狀態(tài)，堆棧指針設(shè)于 70H 處，定時(shí)器 T1 設(shè)為 8位自動(dòng)重裝初值模式，定時(shí)時(shí)間為 13181。 RST 引腳的高電平只要能保持 2 個(gè)機(jī)器周期，單片機(jī)就可以進(jìn)行復(fù)位操作。 ④ EA/Vpp:內(nèi)外 ROM 選擇 /片內(nèi) EPROM 編程電源。 80C51 單片機(jī)一般采用雙列直插 DIP 封裝，共 40 個(gè)引腳（ 如圖 21） 。 8 顯示 在汽車行駛過程中，當(dāng)前車轉(zhuǎn)彎、剎車或后車超車時(shí)都能在本汽車上顯示，并發(fā)出相應(yīng)人性化語(yǔ)音進(jìn)行提醒。若第一位低電平碼 的脈寬小于 2ms，將作誤幀處理。 輸出電路 單片機(jī)從 ～ 輸出前后車的行駛信息提示信號(hào) ， 其中 用于前車左轉(zhuǎn)彎指示及提醒 ， 用于前車右轉(zhuǎn)彎指示及提醒， 用于后車超 車指示 及 提醒， 用于前車剎車提示及提醒 。 系統(tǒng)設(shè)計(jì)原理框圖 如圖 11所示 ： 圖 11 系統(tǒng)設(shè)計(jì)原理圖 基本系統(tǒng)組成 本系統(tǒng)采用 12MHz 晶振時(shí)鐘頻率， 30pF 的瓷片補(bǔ)償電容，上電復(fù)位采用最簡(jiǎn)單的 RC電路，片外存儲(chǔ)器選擇腳 (31腳 EA)接正電源。例如下圖： 圖中是最簡(jiǎn)單的控制，通過對(duì) 口的電平的變化，可以使得 LED 產(chǎn)生變化。當(dāng)時(shí)， Zilog、 Motorola 和 Intel 在微處理器領(lǐng)域三足鼎立。 1972 年 4月，霍夫等人開發(fā)出第一個(gè) 8 位微處理器 Intel 8008。 3 第一章 了解單片機(jī) 單 片 機(jī)的前景 與發(fā)展 知己知彼，方能百戰(zhàn)不殆；學(xué)習(xí)單片機(jī)，就需要了解單片機(jī)。 以單片機(jī)為核心進(jìn)行紅外遙控的汽車行駛監(jiān)測(cè)儀具有安全可靠，成本低、性價(jià)比高的優(yōu)點(diǎn)，具有廣闊的應(yīng)用領(lǐng)域。 隨著 人均購(gòu)買力的上升及 汽車 的增加，汽車安全 系統(tǒng)的 重要 性問題必將成為影響 人們選擇車輛購(gòu)買的一大重要約束條件 ， 一個(gè)完善、安全、可靠的汽車行駛監(jiān)測(cè)儀必將成為車輛必不可少的一部分。 很多關(guān)于單片機(jī)、嵌入式的消息與信息充斥在 IT 行業(yè)，前景有目共睹。 主頻 2MHz 的 8080 芯片運(yùn)算速度比 8008 快 10 倍，可存取 64KB 存儲(chǔ)器，使用了基于6 微米技術(shù)的 6000 個(gè)晶體管，處理速度為 （ Million Instructions Per Second ）。 單片機(jī)簡(jiǎn)述 與分類 單片機(jī)，英文為： Signal Chip Microputer。 8 位單片機(jī)適合初學(xué)者。紅外接收器采用通用遠(yuǎn)紅外接收解調(diào)一體化成品，其器件為三 引腳結(jié)構(gòu)，安裝使用方便，其信號(hào)腳可直接接單片機(jī) 、 及中斷輸入端口。為了增加接收的可靠性 ， 第一位碼寬為 3ms，其 余為 1ms，數(shù)據(jù)幀間隔大于 10ms，如圖 13所示 ： 7 圖 13 紅外線接收器輸出的一幀數(shù)據(jù)的波形 數(shù)據(jù)幀的發(fā)送過程 當(dāng)單片機(jī)檢測(cè)到 ～ 端口為低電平時(shí)，先設(shè)置發(fā)送標(biāo)志，然后依次發(fā)送數(shù)據(jù)幀。 按鍵 當(dāng)汽車轉(zhuǎn)彎或剎車按鍵按下時(shí)，將其動(dòng)作轉(zhuǎn)化為電信號(hào)輸入單片機(jī)。芯片采用 CMOS 技術(shù)，內(nèi)含振蕩器、防混淆濾波器、平滑濾波器、音頻放大器、自動(dòng)靜噪及高密度多電平閃爍存儲(chǔ)陣列。 （ 3） 控制線 :控制線共有 4根， ① ALE/PROG:地址鎖存允許 /片內(nèi) EPROM 編程 脈沖 a、 ALE 功能：用來鎖存 P0口送出的低 8位地址 b、 PROG 功能：片內(nèi)有 EPROM 的芯片，在 EPROM 編程期間 ， 此引腳輸入編程脈沖。 （ 4） I /O引腳 ： 80C51 共有 4 個(gè) 8 位并行 I/O 端口： P0、 P P P3口，共 32 個(gè)引腳。 圖 23 鍵盤電路 當(dāng) 按下 左轉(zhuǎn)彎按鍵時(shí)，其動(dòng)作 轉(zhuǎn)化為電信號(hào)輸入 80C51 單片機(jī) ，左轉(zhuǎn)向開關(guān)閉合，通 過三極管放大，對(duì)應(yīng)的 端口電平變?yōu)?低電平 ，再通過程序轉(zhuǎn)化的編碼顯示本車的左轉(zhuǎn)彎狀態(tài) ；當(dāng)按下右轉(zhuǎn)彎按鍵時(shí)，右轉(zhuǎn)彎開關(guān)閉合， 端口電平變?yōu)榈碗娖?，程序編碼顯示右轉(zhuǎn)彎狀態(tài)；當(dāng)按下剎車按鍵時(shí)，通過三極管放大，對(duì)應(yīng) 輸入端口電平變?yōu)榈碗娖?，由程序轉(zhuǎn)化的編碼顯示本車剎車的狀態(tài)。 主程序 順序檢測(cè) ～ 端口，若端口為低電平，則專發(fā)送程序。 16 結(jié) 論 讀了五 年的大學(xué)，然而本人對(duì)本專業(yè)的認(rèn)識(shí)還是寥寥無幾！雖然在書本上學(xué)過很多套經(jīng)典理論知識(shí)，似乎通俗易懂，但從未付諸實(shí)踐過，也許等到真正進(jìn)入一個(gè)公司時(shí)，才會(huì)體會(huì)到難度有多大；我們?cè)诶蠋熌抢锘驎旧峡吹竭^很多精彩的，似乎輕而易舉，也許親臨其境或親自上陣才能意識(shí)到自己能力的欠缺和知識(shí)的匱乏。t e naturally or easily to them, and so they are trying to follow a predetermined set of rules. Some individuals with autism have normal intelligence, and many have special talents in areas such as music or memory. However, individuals with autism may have other mental or emotional problems that coexist with their autism. Some of these other disorders may include impulse control disorders, obsessivepulsive disorder , mood and anxiety disorders, and mental retardation . PSYCHOLOGICAL AND FAMILY FACTORS. Although Henry Maudsley, in the late 1800s, was the first psychiatrist to focus on very young children with mental disorders, it was the psychiatrist Leo Kanner who coined the phrase early infantile autism in 1943. Kanner believed that the parents of children with autistic behaviors were emotionally cold and intellectually distant. He coined the term refrigerator parents to describe them. His belief that parental personality and behavior played a powerful role in the development of autistic behaviors left a devastating legacy of guilt and selfblame among parents of autistic children that continues to this day. Recent studies are unequivocal, however, in demonstrating that parents of autistic children are no different from parents of healthy children in their personalities or parenting behaviors. In fact, many families with an autistic child also have one or more perfectly healthy children. Because autistic children can be extremely sensitive to change, any change within the family situation can be potentially traumatic to the autistic child. A move, divorce, birth of a sibling or other stressors that occur in the lives of most families may evoke a more extreme reaction from an autistic child. While there is no single neurological abnormality found in children with autistic disorders, some research using noninvasive brain imaging techniques such as magic resonance imaging (MRI) suggests that certain areas of the brain may be involved. Several of the brain areas being researched are known to control emotion and the expression of emotion. These areas include the temporal lobe (large lobe of each side of the brain that contains a sensory area associated with hearing), the limbic system, the cerebellum, the frontal lobe, the amygdala, and the brain stem, which regulates homeostasis (body temperature and heart rate). Recent research has focused particularly on the temporal lobe because of the finding that previously healthy people who sustain temporal lobe damage may develop autisticlike symptoms. In animal research, when the temporal lobe is damaged, social behavior declines, and restless, repetitive motor behaviors 28 are mon. When measured by MRI, total brain volume appears to be greater for those with autistic disorders. Other neurological factors include lesions to the brain, congenital rubella, undiagnosed and untreated phenylketonuria (PKU), tuberous sclerosis, and Rett39。 the ball was the objective. To score, the ball had to be shot through a horizontal, elevated goal. The team with the most points at the end of an allotted time period wins. Early in the history of basketball, the local YMCAs provided the gymnasiums, and membership in the anization grew rapidly. The size of the local gym dictated the number of pla