【正文】 telligent control instruments, and has penetrated into every corner of the people work and life, effectively promote the industry39。假設(shè)使用T/C0，方式1，50ms定時(shí)，fosc=12MHz。 LED2 分隔它帶有8K Flash 可編程和擦除的只讀存儲(chǔ)器（EPROM），該器件采用ATMEL的高密度非易失性存儲(chǔ)器技術(shù)制造，與工業(yè)上標(biāo)準(zhǔn)的80C51和80C52的指令系統(tǒng)及引腳兼容，片內(nèi)Flash 集成在一個(gè)芯片上，可用與解決復(fù)雜的問(wèn)題，且成本較低。當(dāng)使用芯片內(nèi)部時(shí)鐘時(shí)，此二引線端用于外接石英晶體和微調(diào)電容；當(dāng)使用外部時(shí)鐘時(shí)，用于接外部時(shí)鐘脈沖信號(hào)。 晶振電路下圖所示為時(shí)鐘電路原理圖，在STC12C5A08S2芯片內(nèi)部有一個(gè)高增益反相放大器，其輸入端為芯片引腳XTAL1，輸出端為引腳XTAL2。只要保證RESET為高電平的時(shí)間大于兩個(gè)機(jī)器周期，便能正常復(fù)位。只要按規(guī)律控制各發(fā)光段亮、滅，就可以顯示各種字形或符號(hào)。圖27 數(shù)碼管的硬件連接示意圖系統(tǒng)采用動(dòng)態(tài)顯示方式，用P0口來(lái)控制LED數(shù)碼管的段控線，而用P2口來(lái)控制其位控線。單片機(jī)軟件的設(shè)計(jì)主要包括執(zhí)行軟件（完成各種實(shí)質(zhì)性功能）的設(shè)計(jì)和監(jiān)控軟件的設(shè)計(jì)。圖33 按鍵檢測(cè)流程圖 時(shí)間顯示流程圖時(shí)間顯示是先將秒個(gè)位計(jì)算顯示，然后是秒十位計(jì)算顯示，再是分個(gè)位計(jì)算顯示，再然后是分十位顯示，再就是時(shí)個(gè)位計(jì)算顯示，最后是時(shí)十位顯示。//微秒級(jí)延時(shí)子函數(shù)void delayus(unsigned int us) { unsigned char t。 }}//主函數(shù)void main(){ P2=0xff。 delayus(150)。 P0=disp[c]。 P2=0xbf。 TH0=0x3C。 if(c==10) { c=0。(e==4)) { f=e=0。基于單片機(jī)實(shí)現(xiàn)電子時(shí)鐘，僅僅是眾多方法之一。另外，要做好一個(gè)課程設(shè)計(jì)，就必須做到：在設(shè)計(jì)程序之前，對(duì)所用單片機(jī)的內(nèi)部結(jié)構(gòu)有一個(gè)系統(tǒng)的了解，知道該單片機(jī)內(nèi)有哪些資源；要有一個(gè)清晰的思路和一個(gè)完整的的軟件流程圖；在設(shè)計(jì)程序時(shí)，不能妄想一次就將整個(gè)程序設(shè)計(jì)好，反復(fù)修改、不斷改進(jìn)是程序設(shè)計(jì)的必經(jīng)之路；要養(yǎng)成注釋程序的好習(xí)慣，一個(gè)程序的完美與否不僅僅是實(shí)現(xiàn)功能，而應(yīng)該讓人一看就能明白你的思路，這樣也為資料的保存和交流提供了方便；在設(shè)計(jì)課程過(guò)程中遇到問(wèn)題是很正常德，但我們應(yīng)該將每次遇到的問(wèn)題記錄下來(lái)，并分析清楚，以免下次再碰到同樣的問(wèn)題的課程設(shè)計(jì)結(jié)束了，但是從中學(xué)到的知識(shí)會(huì)讓我受益終身。 鄭君里，應(yīng)啟珩，楊為理. 信號(hào)與系統(tǒng)（第二版）下冊(cè)[M]. 高等教育出版社,2000[3]ta damagesbased agreement, you should make sure you39。s about how he felt and I would like to speak to him first to find out what his experience was.Uefa has May be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been very messy, in my mind constantly. Always feel oneself should go to do something, or write something. Twenty years of life trajectory deeply shallow, suddenly feel something, do it.　　一字開頭的年齡已經(jīng)到了尾聲。t want to give vent to out your inner voice can be in the high school children of the feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found himself has already can39。那些曾經(jīng)所謂的非做不可，只是青蔥年華里自己給自己注射的一支強(qiáng)心劑，或者說(shuō)，是自以為是的精神寄托罷了。ll be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end. Skydiver preps for the big jumpWhen he jumps, he is expected to reach the speed of sound 690 mph (1,110 kph) in less than 40 seconds. Like hitting the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him pletely.If he goes too fast or spins out of control, he has a stabilization parachute that can be deployed to slow him down. His team hopes it39。突然想到那件藍(lán)格子襯衫；那些被折成各種各樣形狀的信紙；那段從街角深巷伊始的友誼；還有那場(chǎng)還沒有開始就宣告了終結(jié)的邂逅計(jì)劃……那些年那些天的非做不可，終于和青春一樣，都將在我們的人生中謝幕。也曾經(jīng)好像已經(jīng)下定了決心去做某件事，但更多的時(shí)候是最后又打起了退堂鼓。t really grow up, it seems is not so important。s actions.CSKA said they were surprised and disappointed by Toure39。s 150th anniversary celebrations and will attend City39。t charge you more than 35% of your pensation your employer dismisses you and you think that you have been dismissed unfairly.For more information about dismissal and unfair dismissal, see參 考 文 獻(xiàn)[1]但當(dāng)拿到題目時(shí)，確實(shí)不知道怎么著手，有些迷茫，上網(wǎng)查資料，問(wèn)老師，在老師的幫助下，歷時(shí)兩個(gè)星期，解決一個(gè)又一個(gè)的困難，終于完成任務(wù)。隨著生產(chǎn)力的發(fā)展，社會(huì)的進(jìn)步，生產(chǎn)生活對(duì)時(shí)鐘的需求越來(lái)越大，對(duì)時(shí)鐘的體型、功能的要求也各有不同。 } } } } } if((f==2)amp。 if(b==6) { b=0。 timechange()。 P0=disp[10]。 delayus(150)。 while(1) { P2=0xfe。 } if(HU==0) { e=e+1。unsigned int a=0,b=0,c=0,d=0,e=0,f=0,s=20。程序流程圖如圖32所示：圖32 定時(shí)器流程圖 按鍵檢測(cè)流程圖按鍵處理是先檢測(cè)分按鍵是否按下，分加按鍵如果按下，分就加1，分減按鍵如果按下，分就減1；再檢測(cè)時(shí)按鍵是否按下，時(shí)加按鍵如果按下，時(shí)就加1，時(shí)減按鍵如果按下，時(shí)就減1，如果沒有鍵按下，就把時(shí)間顯示出來(lái)。故在按鍵較少時(shí)，采用圖29所示電路。對(duì)于多位LED顯示器，通常都是采用動(dòng)態(tài)掃描的方法進(jìn)行顯示。