【正文】 telligent control instruments, and has penetrated into every corner of the people work and life, effectively promote the industry39。假設使用T/C0，方式1，50ms定時，fosc=12MHz。 LED2 分隔它帶有8K Flash 可編程和擦除的只讀存儲器（EPROM），該器件采用ATMEL的高密度非易失性存儲器技術制造，與工業(yè)上標準的80C51和80C52的指令系統(tǒng)及引腳兼容，片內Flash 集成在一個芯片上，可用與解決復雜的問題，且成本較低。當使用芯片內部時鐘時，此二引線端用于外接石英晶體和微調電容；當使用外部時鐘時，用于接外部時鐘脈沖信號。 晶振電路下圖所示為時鐘電路原理圖，在STC12C5A08S2芯片內部有一個高增益反相放大器，其輸入端為芯片引腳XTAL1，輸出端為引腳XTAL2。只要保證RESET為高電平的時間大于兩個機器周期，便能正常復位。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。圖27 數(shù)碼管的硬件連接示意圖系統(tǒng)采用動態(tài)顯示方式，用P0口來控制LED數(shù)碼管的段控線，而用P2口來控制其位控線。單片機軟件的設計主要包括執(zhí)行軟件（完成各種實質性功能）的設計和監(jiān)控軟件的設計。圖33 按鍵檢測流程圖 時間顯示流程圖時間顯示是先將秒個位計算顯示，然后是秒十位計算顯示，再是分個位計算顯示，再然后是分十位顯示，再就是時個位計算顯示，最后是時十位顯示。//微秒級延時子函數(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?；趩纹瑱C實現(xiàn)電子時鐘，僅僅是眾多方法之一。另外，要做好一個課程設計，就必須做到：在設計程序之前，對所用單片機的內部結構有一個系統(tǒng)的了解，知道該單片機內有哪些資源；要有一個清晰的思路和一個完整的的軟件流程圖；在設計程序時，不能妄想一次就將整個程序設計好，反復修改、不斷改進是程序設計的必經(jīng)之路；要養(yǎng)成注釋程序的好習慣，一個程序的完美與否不僅僅是實現(xiàn)功能，而應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；在設計課程過程中遇到問題是很正常德，但我們應該將每次遇到的問題記錄下來，并分析清楚，以免下次再碰到同樣的問題的課程設計結束了，但是從中學到的知識會讓我受益終身。 鄭君里，應啟珩，楊為理. 信號與系統(tǒng)（第二版）下冊[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心劑，或者說，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；還有那場還沒有開始就宣告了終結的邂逅計劃……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[1]但當拿到題目時，確實不知道怎么著手，有些迷茫，上網(wǎng)查資料，問老師，在老師的幫助下，歷時兩個星期，解決一個又一個的困難，終于完成任務。隨著生產力的發(fā)展，社會的進步，生產生活對時鐘的需求越來越大，對時鐘的體型、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 定時器流程圖 按鍵檢測流程圖按鍵處理是先檢測分按鍵是否按下，分加按鍵如果按下，分就加1，分減按鍵如果按下，分就減1；再檢測時按鍵是否按下，時加按鍵如果按下，時就加1，時減按鍵如果按下，時就減1，如果沒有鍵按下，就把時間顯示出來。故在按鍵較少時，采用圖29所示電路。對于多位LED顯示器，通常都是采用動態(tài)掃描的方法進行顯示。