【正文】 子 時(shí) 鐘 的 設(shè) 計(jì) 與 制 作 17 保護(hù)現(xiàn)場(chǎng) 設(shè)置子程序初值 秒單元加 1 秒單元等于 60 6 六十6066060=60=60 秒單元清零 分單元加 1 分單元等于 60 6 六十6066060=60=60 分單元清零 時(shí)單元加 1 時(shí)單元等于 24 6 六十6066060=60=60 時(shí)單元清零 恢復(fù)現(xiàn)場(chǎng) RET Y Y Y Y 1 秒時(shí)間到 6 六十6066060=60=60 N N N N 電 子 時(shí) 鐘 的 設(shè) 計(jì) 與 制 作 18 圖七（上頁(yè)圖） 中斷服務(wù)流程圖 ： 圖八 T0 中斷 保護(hù)現(xiàn)場(chǎng) 20 次中斷到否 秒單元加 1 單元清零 恢復(fù)現(xiàn)場(chǎng)、中斷返回 N Y 電 子 時(shí) 鐘 的 設(shè) 計(jì) 與 制 作 19 數(shù)碼管顯示模塊 本系統(tǒng)公用 ，從右到左一次顯示秒個(gè)位，秒時(shí)位， 分隔符 ，分個(gè)位，分十位， 分隔符 ，時(shí)個(gè)位，時(shí)十位 。在本系統(tǒng)中數(shù)碼管顯示采用軟件譯碼動(dòng)態(tài)顯示。從 P1 口輸出，同時(shí)在 P2 口將對(duì)應(yīng)的位選碼輸出，選中顯示的數(shù)碼管，就能在相應(yīng)的數(shù)碼管上顯示顯示緩沖區(qū)的內(nèi)容 。分單元加到 60的時(shí)候，則對(duì)時(shí)單元加 1，同時(shí)分單元清零，時(shí)單元加到 24 的時(shí)候則對(duì)時(shí)單元清零，標(biāo)志一天時(shí)間計(jì)滿。 按鍵處理模塊： 按鍵處理設(shè)置為：如果沒有按鍵，則時(shí)鐘正常走下去，當(dāng)?shù)谝淮伟聪?K0 按鍵時(shí)候，進(jìn)入調(diào)分狀態(tài)時(shí)鐘停止走動(dòng)，按下 K1 鍵可以對(duì)分進(jìn)行加 1 操作，按下 K2鍵的時(shí)候可以對(duì)分進(jìn)行減 1 操作。當(dāng) K0 第三次按下的時(shí)候時(shí)鐘恢復(fù)正常走動(dòng)，退出調(diào)時(shí)間的模式。這次對(duì) AT89S51 有了一個(gè)全面的認(rèn)識(shí)，在此基礎(chǔ)上結(jié)合以前所學(xué)的專業(yè)知識(shí)，從而把我所學(xué)的知識(shí)貫穿到一起，對(duì)本專業(yè)有了一個(gè)更全面的認(rèn)識(shí)！總之這次畢業(yè)設(shè)計(jì)讓我把理論設(shè)計(jì)和工程實(shí)踐相結(jié)合、鞏固基礎(chǔ)知識(shí) 與培養(yǎng)創(chuàng)新意識(shí)相結(jié)合、個(gè)人作用和集體協(xié)作相結(jié)合等方面來(lái)培養(yǎng)自身的綜合素質(zhì)。 最后，我要感謝我的指導(dǎo)老師，在這次畢業(yè)設(shè)計(jì)中給了我許多的幫助。 電 子 時(shí) 鐘 的 設(shè) 計(jì) 與 制 作 22 參考文獻(xiàn) [1] 徐愛鈞．單片機(jī)原理實(shí)用教程－－基于 Protrues 虛擬仿真 [M]．北京 ： 電子工業(yè)出版社 .20221 [2] 李萍． AT89S51 單片機(jī)、原理、開發(fā)與應(yīng)用實(shí)例 [M]．北京 ： 中國(guó)電力出版社． 20227 [3] 張曄、王玉民等．單片機(jī)應(yīng)用技術(shù) [M] ．北京 ： 高等教育出版社． 20223 [4] 付家才等．單片機(jī)控制工程實(shí)踐技術(shù) [M] ．北京 ： 化學(xué)工業(yè)出版社． 20225 電 子 時(shí) 鐘 的 設(shè) 計(jì) 與 制 作 23 附錄一 單 片機(jī)語(yǔ)言程序清單： 定時(shí)中斷子程序 : INT_T0:MOV TH0,3CH MOV TL0,0B0H 。計(jì)數(shù)器加一 MOV A,TCNT 。判斷計(jì)數(shù)是否到了 20 了嗎？ INC SECOND 。計(jì)數(shù)器清零 MOV A,SECOND CJNE A,60,RETUNE 。分單元加一 MOV SECOND,0 。判斷分是否到了 60 INC HOUR MOV MINUTE,0 MOV A,HOUR CJNE A,24,RETUNE 。時(shí)分秒清零 MOV MINUTE,0 MOV SECOND,0 MOV TCNT,0 。返回 T0 中斷入口 顯示子程 序 : DISPLAY:MOV A,SECOND MOV B,10 電 子 時(shí) 鐘 的 設(shè) 計(jì) 與 制 作 24 DIV AB 。查顯示數(shù)據(jù)碼段 MOV P0,A 。去抖動(dòng) SETB 。把寄存器 B 中的余數(shù)送 A 即秒個(gè)位 CLR 。查顯示數(shù)據(jù)碼段 MOV P0,A 。顯示秒個(gè)位 CLR MOV P0,40H 。t agree with the disciplinary action your employer has taken against you ? your employer dismisses you and you think that you have been dismissed unfairly. For more information about dismissal and unfair dismissal, see Dismissal. You can make a claim to an employment tribunal, even if you haven39。t charge you more than 35% of your pensation if you win the case. If you are thinking about signing up for a damagesbased agreement, you should make sure you39。s antiracism taskforce, is in London for the Football Association39。s Premier League match at Chelsea on Sunday. I am going to be at the match tomorrow and I have asked to meet Yaya Toure, he told BBC Sport. For me it39。s 21 win. Michel Platini, president of European football39。s actions. 電 子 時(shí) 鐘 的 設(shè) 計(jì) 與 制 作 28 CSKA said they were surprised and disappointed by Toure39。 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?？傆X得自己自己似乎應(yīng)該去做點(diǎn)什么，或者 寫點(diǎn)什么。 The end of our life, and can meet many things really do? 而窮盡我們的一生，又能遇到多少事情是真正地非做不可？ During my childhood, think lucky money and new clothes are necessary for New Year, but as the advance of the age, will be more and more found that those things are optional。t really grow up, it seems is not so important。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。 Originally, this world, can produce a chemical reaction to an event, in addition to resolutely, have to do, and time. 原來(lái)，這個(gè)世界上，對(duì)某個(gè)事件能產(chǎn)生化學(xué)反應(yīng)的，除了非做不可的堅(jiān)決，還有，時(shí)間。s time, your ideas are always special to clear. Want, want, line is clear, as if nothing could shake his. Also once seemed to be determined to do something, but more often is he backed out at last. Dislike his cowardice, finally found that there are a lot of love, there are a lot of miss, like shadow really have been doomed. Those who do, just green years oneself give oneself an arm injection, or is a selfrighteous spiritual. 一個(gè)人的時(shí)候，自己的想法總是特別地清晰。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。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。 Those were broken into various shapes of stationery。 Have declared the end of the encounter that haven39。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。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 jump When 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. 電 子 時(shí) 鐘 的 設(shè) 計(jì) 與 制 作 30 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。t. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters). cause there