【正文】 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。 Have declared the end of the encounter that haven39。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。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。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。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。 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(kāi)頭的年齡已經(jīng)到了尾聲。s 21 win.Michel Platini, president of European football39。s about how he felt and I would like to speak to him first to find out what his experience was.Uefa hasEmployment tribunals.The (lack of) air up there Watch mCayman Islandsbased Webb, the head of Fifa39。a damagesbased agreement, you should make sure you39。Further help.If you are being represented by a solicitor at the tribunal, they may ask you to sign an agreement where you pay their fee out of your pensation if you win the case. This is known as at you don39。其次，在這次課程設(shè)計(jì)中，我們運(yùn)用到了以前所學(xué)的專業(yè)課知識(shí)，如：CAD制圖、匯編語(yǔ)言、模擬和數(shù)字電路知識(shí)等。使我在單片機(jī)的基本原理、單片機(jī)應(yīng)用系統(tǒng)開(kāi)發(fā)過(guò)程，以及在常用編程設(shè)計(jì)思路技巧（特別是匯編語(yǔ)言）的掌握方面都能向前邁了一大步，為日后成為合格的應(yīng)用型人才打下良好的基礎(chǔ)。系統(tǒng)統(tǒng)采用MSC51系列單片機(jī)Intel8051和可編程并行I/O接口芯片8255A為中心器件來(lái)設(shè)計(jì)交通燈控制器，實(shí)現(xiàn)了能根據(jù)實(shí)際車流量通過(guò)8031芯片的P1口設(shè)置紅、綠燈燃亮?xí)r間的功能；紅綠燈循環(huán)點(diǎn)亮，倒計(jì)時(shí)剩5秒時(shí)黃燈閃爍警示（交通燈信號(hào)通過(guò)PA口輸出，顯示時(shí)間直接通過(guò)8255的PC口輸出至雙位數(shù)碼管）；車輛闖紅燈報(bào)警；綠燈時(shí)間可檢測(cè)車流量并可通過(guò)雙位數(shù)碼管顯示。顯示十位 MOV DPTR,TAB MOVC A,A+DPTR MOV DPTR,0002H MOVX DPTR,A MOV DPTR,0001H MOV A,0F7H MOVX DPTR,A LCALL DELAYDS4: MOV A,7AH 。若綠燈倒計(jì)時(shí)完畢，不再檢測(cè)車流量 JZ N3 JB ,T03 INC R7 CJNE R7,64H,E1 MOV R7,00H 。R3中值二轉(zhuǎn)十顯示轉(zhuǎn)換 DIV AB MOV 79H,A MOV 7AH,BDIS: MOV A,79H 。報(bào)警初值減一T01: ACALL DISP 。給定時(shí)器T0送定時(shí)10ms的初值 MOV TH0,0F1H INC R4 INC R5 CJNE R5,0FAH,T01 。若倒計(jì)時(shí)完畢，不再報(bào)警 CLR 。 CJNE R3,00H,N3 。黃燈閃爍5秒程序N3: MOV R3,05H MOV DPTR,0000H 。閃爍時(shí)間達(dá)5秒則退出。置8255A口，東西，南北方向黃燈亮 MOV A,0D4H MOVX DPTR,AN11: MOV R4,00HN12: CJNE R4,7DH,$ 。東西方向禁止，南北方向通行 MOV R3,A MOV DPTR,0000H 。存入東西方向紅燈初始時(shí)間 MOV R3,A LCALL DISP1 LCALL DELAY AJMP AGAIN。R0清零 MOV R0,A 。選擇邊沿觸發(fā)方式 MOV DPTR ,0003H MOV A, 80H 。設(shè)置T1為計(jì)數(shù)方式,T0為定時(shí)方式，且都工作于模式1 MOV TH1,00H 。定時(shí)器0的中斷程序入口地址 LJMP T0_INT 。 8255輸出信號(hào)與數(shù)碼管的連接： LED 燈的顯示原理:通過(guò)同名管腳上所加電平的高低來(lái)控制發(fā)光二極管是否點(diǎn)量而顯示不同的字形如 SP，g,f,e,d,c,b,a 管角上加上７ＦＨ所以　ＳＰ上為０伏，不亮其余為ＴＴＬ高電平，全亮則顯示為８采用共陰級(jí)連接:其中 PC0\PB0a,PC1\PB1b, PC2\PB2c,PC3\PB3d,PC4\PB4e, PC5\PB5f,PC6\PB6gPC7\PB7 SP接地顯示數(shù)值dop g f e d c b a 驅(qū)動(dòng)代碼（16進(jìn)制）00 0 1 1 1 1 1 1 3FH1 0 0 0 0 0 1 1 006H2 0 1 0 1 1 0 1 15BH3 0 1 0 0 1 1 1 14FH4 0 1 1 0 0 1 1 066H5 0 1 1 0 1 1 0 06DH6 0 1 1 1 1 1 0 07DH7 0 0 0 0 0 1 1 107H8 0 1 1 1 1 1 1 17FH 表 3 驅(qū)動(dòng)代碼表 8255與8051的連接：用8051的P0 口的 連接8255的片選信號(hào)cs 我們用8031的地址采用全譯碼方式， =0 時(shí)片選有效， 其他無(wú)效， 用于選擇8255端口 A7 A6 A5 A4 A3 A2 A1 A01 X X X X X 0 0 00H為8255 的PA口1 X X X X X 0 1 01H 為8255的PB口1 X X X X X 1 0 02H 為8255的PC口1 X X X X X 1 1 03H 為8255的控制口由于8051是分時(shí)對(duì)8255和儲(chǔ)存器進(jìn)行訪問(wèn)所以8051的P0口不會(huì)發(fā)生沖突 程序設(shè)計(jì)開(kāi)始初始化等待鍵盤事件顯示程序處理鍵盤事件處理 圖8 圖9 程序流程圖 程序源代碼 ORG 0000H 。 擴(kuò)展的方法有兩種：（1）借用外部RAM地址來(lái)擴(kuò)展I/O端口；（2）采用I/O接口新片來(lái)擴(kuò)充。 具體的延時(shí)程序分析： DELAY:MOV R4,08H 延時(shí)1秒子程序 DE2:LCALL DELAY1 DJNZ R4,DE2 RET DELAY1:MOV R6,0 延時(shí)125ms 子程序 MOV R5,0DE1: DJNZ R5,$ DJNZ R6,DE1 RET MOV Rn，DATA 字節(jié)數(shù)數(shù)為2 機(jī)器周期數(shù)為1所以此指令的執(zhí)行時(shí)間為2ms DELAY1 為一個(gè)雙重循壞 循環(huán)次數(shù)為256*256=65536 所以延時(shí)時(shí)間=65536*2=131072us 約為125us DELAY R4設(shè)置的初值為8 主延時(shí)程序循環(huán)8次，所以125us*8= 1秒 由于單片機(jī)的運(yùn)行速度很快其他的指令執(zhí)行