【正文】 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. 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。 １８ 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。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. 一個人的時候，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. 一字開頭的年齡已經(jīng)到了尾聲。s 21 win. Michel Platini, president of European football39。s antiracism taskforce, is in London for the Football Association39。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。 ； R1：查表偏址寄存器， B：查表首址， R2：掃描地址（從 00～ 0FH）。 致謝 本文是在黃金明老師的悉心指導(dǎo)下完成的。 三， 文章給出了系統(tǒng)具體的硬件設(shè)計方案 ,硬件結(jié)構(gòu)電路圖，軟件流程圖和具體匯編語言程序設(shè)計與調(diào)試等方面。本系統(tǒng)具有硬件少，結(jié)構(gòu)簡單，容易實現(xiàn)，性能穩(wěn)定可靠，成本低等特點。 顯示效果處理程序的內(nèi)容及方法非常廣泛，其調(diào)試過程在此不作具體討論，讀者可以照源程序自行分析。軟件部分需要調(diào)試的主要有顯示屏刷新頻率及顯示效果兩部分。由于單片機沒有停機指令， 所以可以設(shè)置系統(tǒng)程序不斷的循環(huán)執(zhí)行上述顯示效果。圖 4為顯示驅(qū)動程序（ 顯示屏掃描函數(shù)）流程圖。 從有利于實現(xiàn)較復(fù)雜的算法（顯示效果處理）和有利于程序結(jié)構(gòu)化考慮，顯示屏程序適宜采用 C 語言編寫。根據(jù)軟件分層次設(shè)計的原理，可以把顯示屏的軟件系統(tǒng)分為兩層 ；第一層是底層的顯示驅(qū)動程序，第二層是上層的系統(tǒng)應(yīng)用程序。但因為 QH 受輸出鎖存器的打入控 制，所以還從輸出鎖存器前引出QH，作為與移位寄存器完全同步的級聯(lián)輸出。引腳 G是輸出三態(tài)門的開放信號，只有當(dāng)其為低時鎖存器的輸出才開放，否則為高組態(tài)。引腳 SI 是串行數(shù)據(jù)的輸入端。 列驅(qū)動電路 列驅(qū)動電路有集成電路 74HC595 構(gòu)成。單片機的串口與列驅(qū)動器相連，用來顯示數(shù)據(jù)。這樣，本行已準(zhǔn)備好的數(shù)據(jù)打入并行鎖存器進(jìn)行顯示時，串并移位寄存器就可以準(zhǔn)備下一行的列數(shù)據(jù)，而不會影響本行的顯 ５ 示。即 在顯示本行各列數(shù)據(jù)的同時，傳送下一列數(shù)據(jù)。但是，串行傳輸過程較長，數(shù)據(jù)按順序一位一位地輸出給列驅(qū)動器，只有當(dāng)一行的各列數(shù)據(jù)都以傳輸?shù)轿恢螅@一行的各列才能并行地進(jìn)行顯示。從控制電路到列驅(qū)動器的數(shù)據(jù)傳輸可以采用并列方式或串行方式。當(dāng)這樣輪回的速度足夠快（每秒 24 次以上），由于人眼的視覺暫留現(xiàn)象，就能夠看到顯示屏上穩(wěn)定的圖形了。這個數(shù)字很龐大，因為我們僅僅是 16ｘ 16 的點陣，在實際應(yīng)用中的顯示屏往往要大得多，這樣在鎖存器上花的成本將是一個很龐 大的數(shù)字。 設(shè)計一個室內(nèi)用 16ｘ 16 的點陣 LED圖文顯示屏，要求 在目測條件下 LED 顯示屏各點亮度均勻、充足，可顯示圖形和文字， 顯示圖形和文字應(yīng)穩(wěn)定、清晰無串?dāng)_。 ③第 3 階 段 (1983 年以后 )，以 MCS96 系列為代表，稱 16 位單片機。在片外：尋址范圍只有 4KB；芯片引腳有 40 個。 ③控制功能強： 具有豐富的控制指令：如：條件分支轉(zhuǎn)移指令， I/O 口的邏輯操作指令，位處理指令。 MCS51 系列單片機簡介 MCS51 系列單片機及其特點 ①可靠性高： 因為芯片是按工業(yè)測控環(huán)境要求設(shè)計的，故抗干 擾的能力優(yōu)于 PC 機。 LED 顯示屏分為圖文顯示屏和視頻顯示屏，均由 LED 矩陣塊組成。在 LED 的 p n 結(jié)附近 ,n 型材料中多數(shù)載流子是電子 ,p 型材料中多數(shù)載流子是空穴。在某些半導(dǎo)體材料 的PN結(jié)中，注入的少數(shù)載流子與多數(shù)載流子復(fù)合時會把多余的能量以光的形式釋放出來，從而把電能直接轉(zhuǎn)換為光能。 關(guān)鍵詞 ： MCS51； LED；單片機 ２ a kind of simple 16ｘ 16 LED display screen design process based on MCS51 Student majoring in Automation LiuLongChao Tutor HuangJinMing Abstract： As a popular display device ponent, LED dotmatrix display board consists of several independent LED (Light Emitting Diode). The LED dotmatrix display board can display the number or sign, and it is usually used to show time, speed, the state of system etc. This paper introduces a kind of simple 16ｘ 16 LED display screen design process based on MCS51 single chip miniputer . The detail hardware scheme, software flow and assemble language programmer design and so on is followed. The display part can be cascaded to meet the need. The practice proves the design is lowcost and effective. Key words: MCS51； LED； MCU 引言 LED 顯示屏顯示畫面色彩鮮艷，立體感強，靜如油畫，動如電影，廣泛應(yīng)用于車站、碼頭、機場、商場、醫(yī)院、賓館、銀行、證券市場、建筑市場、拍賣行、工業(yè)企業(yè)管理和其它公共場所。目 錄 摘要 .................................................................... １ 關(guān)鍵詞 .................................................................. １ Abstract ................................................................ ２ Key words ............................................................... ２ 引言 .................................................................... ２ .............................................................. ３ LED 及 LED 顯示屏 ........................................