⭐ 欢迎来到虫虫下载站! | 📦 资源下载 📁 资源专辑 ℹ️ 关于我们
⭐ 虫虫下载站

📄 7_2_3 8255a应用举例.htm

📁 单片机并口扩展芯片8255A源码
💻 HTM
📖 第 1 页 / 共 4 页
字号:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3c.org/TR/1999/REC-html401-19991224/loose.dtd">
<!-- saved from url=(0073)http://www.tyut.edu.cn/kecheng1/2008/site04/courseware/chapter7/7.2.3.htm -->
<HTML xmlns="http://www.w3.org/1999/xhtml"><HEAD><TITLE>7.2.3 8255A应用举例</TITLE>
<META http-equiv=Content-Type content="text/html; charset=gb2312">
<STYLE type=text/css>BODY {
	MARGIN-TOP: 0px; BACKGROUND-IMAGE: url(image/171.gif); MARGIN-LEFT: 0px
}
.STYLE4 {
	FONT-SIZE: xx-large; FONT-FAMILY: "隶书"
}
.STYLE23 {
	FONT-WEIGHT: bold; FONT-SIZE: xx-large; COLOR: #cc3300
}
.STYLE24 {
	COLOR: #00cc33
}
.STYLE29 {
	FONT-SIZE: x-large; COLOR: #000000
}
.STYLE32 {
	FONT-SIZE: xx-large; COLOR: #cc3300; FONT-FAMILY: "隶书"
}
A:link {
	TEXT-DECORATION: none
}
A:visited {
	TEXT-DECORATION: none
}
A:hover {
	TEXT-DECORATION: none
}
A:active {
	TEXT-DECORATION: none
}
.STYLE40 {
	FONT-SIZE: medium
}
.STYLE42 {
	FONT-SIZE: xx-large; COLOR: #339999
}
.STYLE45 {
	FONT-WEIGHT: bold; FONT-SIZE: x-large; COLOR: #000000
}
</STYLE>

<SCRIPT type=text/JavaScript>
<!--
function mmLoadMenus() {
  if (window.mm_menu_0227182117_0) return;
                      window.mm_menu_0227182117_0 = new Menu("root",209,18,"",12,"#000000","#FFFFFF","#CCCCCC","#000084","left","middle",3,0,100,-5,7,true,false,true,0,true,true);
  mm_menu_0227182117_0.addMenuItem("第一节&nbsp;中段概述","window.open('../chapter6/6.1.html', '_self');");
  mm_menu_0227182117_0.addMenuItem("第二节&nbsp;80486微处理器中断系统","window.open('../chapter6/6.2.html', '_self');");
  mm_menu_0227182117_0.addMenuItem("第三节&nbsp;可编程中断控制器8259A","window.open('../chapter6/6.3.html', '_self');");
   mm_menu_0227182117_0.hideOnMouseOut=true;
   mm_menu_0227182117_0.bgColor='#555555';
   mm_menu_0227182117_0.menuBorder=1;
   mm_menu_0227182117_0.menuLiteBgColor='#FFFFFF';
   mm_menu_0227182117_0.menuBorderBgColor='#777777';
      window.mm_menu_0404192249_0 = new Menu("root",291,18,"",12,"#000000","#FFFFFF","#CCCCCC","#000084","left","middle",3,0,100,-5,7,true,false,true,0,false,true);
  mm_menu_0404192249_0.addMenuItem("第一节&nbsp;接口概述","window.open('7.1.1.htm', '_self');");
  mm_menu_0404192249_0.addMenuItem("第二节&nbsp;可编程并行接口芯片8255A及其应用","window.open('7.2.1.htm', '_self');");
  mm_menu_0404192249_0.addMenuItem("第三节&nbsp;可编程定时/计数器8254及其应用","window.open('7.3.1.htm', '_self');");
  mm_menu_0404192249_0.addMenuItem("第四节&nbsp;DMA控制器8237A及其应用","window.open('7.4.1.htm', '_self');");
  mm_menu_0404192249_0.addMenuItem("第五节&nbsp;可编程串行通信接口8250/16550及其应用","window.open('7.5.1.htm', '_self');");
  mm_menu_0404192249_0.addMenuItem("第六节&nbsp;A/D与D/A转换器及其应用","window.open('7.6.1.htm', '_self');");
  mm_menu_0404192249_0.addMenuItem("第七节&nbsp;多功能外围接口芯片组简介","window.open('7.7.1.htm', '_self');");
   mm_menu_0404192249_0.hideOnMouseOut=true;
   mm_menu_0404192249_0.bgColor='#555555';
   mm_menu_0404192249_0.menuBorder=1;
   mm_menu_0404192249_0.menuLiteBgColor='#FFFFFF';
   mm_menu_0404192249_0.menuBorderBgColor='#777777';
window.mm_menu_0404192844_0 = new Menu("root",218,18,"",12,"#000000","#FFFFFF","#CCCCCC","#000084","left","middle",3,0,100,-5,7,true,false,true,0,true,true);
  mm_menu_0404192844_0.addMenuItem("第一节&nbsp;总线概述","window.open('../chapter8/8.1.1.htm', '_self');");
  mm_menu_0404192844_0.addMenuItem("第二节&nbsp;PCI总线","window.open('../chapter8/8.2.1.htm', '_self');");
  mm_menu_0404192844_0.addMenuItem("第三节&nbsp;通用串行总线USB&nbsp;","window.open('../chapter8/8.3.1.htm', '_self');");
  mm_menu_0404192844_0.addMenuItem("第四节&nbsp;高速串行总线&nbsp;IEEE&nbsp;1394","window.open('../chapter8/8.4.1.htm', '_self');");
   mm_menu_0404192844_0.hideOnMouseOut=true;
   mm_menu_0404192844_0.bgColor='#555555';
   mm_menu_0404192844_0.menuBorder=1;
   mm_menu_0404192844_0.menuLiteBgColor='#FFFFFF';
   mm_menu_0404192844_0.menuBorderBgColor='#777777';
  window.mm_menu_0404193055_0 = new Menu("root",187,18,"",12,"#000000","#FFFFFF","#CCCCCC","#000084","left","middle",3,0,100,-5,7,true,false,true,0,true,true);

  mm_menu_0404193055_0.addMenuItem("第一节&nbsp;键盘与键盘接口","window.open('../chapter9/9.1.1.htm', '_self');");
  mm_menu_0404193055_0.addMenuItem("第二节&nbsp;鼠标接口","window.open('../chapter9/9.2.1.htm', '_self');");
  mm_menu_0404193055_0.addMenuItem("第三节&nbsp;显示器与显示卡","window.open('../chapter9/9.3.1.htm', '_self');");
  mm_menu_0404193055_0.addMenuItem("第四节&nbsp;打印机和扫描仪接口","window.open('../chapter9/9.4.1.htm', '_self');");
  mm_menu_0404193055_0.addMenuItem("第五节&nbsp;网络接口","window.open('../chapter9/9.5.1.htm', '_self');");
   mm_menu_0404193055_0.hideOnMouseOut=true;
   mm_menu_0404193055_0.bgColor='#555555';
   mm_menu_0404193055_0.menuBorder=1;
   mm_menu_0404193055_0.menuLiteBgColor='#FFFFFF';
   mm_menu_0404193055_0.menuBorderBgColor='#777777';
window.mm_menu_0404193245_0 = new Menu("root",187,18,"",12,"#000000","#FFFFFF","#CCCCCC","#000084","left","middle",3,0,100,-5,7,true,false,true,0,true,true);
  mm_menu_0404193245_0.addMenuItem("第一节&nbsp;微型计算机发展简史","window.open('../chapter1/1.1.html', '_self');");
  mm_menu_0404193245_0.addMenuItem("第二节&nbsp;微型计算机运算基础","window.open('../chapter1/1.2.htm', '_self');");
  mm_menu_0404193245_0.addMenuItem("第三节&nbsp;微型计算机系统","window.open('../chapter1/1.3.htm', '_self');");
   mm_menu_0404193245_0.hideOnMouseOut=true;
   mm_menu_0404193245_0.bgColor='#555555';
   mm_menu_0404193245_0.menuBorder=1;
   mm_menu_0404193245_0.menuLiteBgColor='#FFFFFF';
   mm_menu_0404193245_0.menuBorderBgColor='#777777';
window.mm_menu_0404200259_0 = new Menu("root",277,18,"",12,"#000000","#FFFFFF","#CCCCCC","#000084","left","middle",3,0,100,-5,7,true,false,true,0,true,true);
  mm_menu_0404200259_0.addMenuItem("第一节&nbsp;Intel&nbsp;8086&nbsp;16位微处理器","window.open('../chapter2/2.1.html', '_self');");
  mm_menu_0404200259_0.addMenuItem("第二节&nbsp;Intel&nbsp;80486&nbsp;32位微处理器","window.open('../chapter2/2.2.htm', '_self');");
  mm_menu_0404200259_0.addMenuItem("第三节&nbsp;Intel&nbsp;80486微处理器的工作模式&nbsp;","window.open('../chapter2/2.3.htm', '_self');");
  mm_menu_0404200259_0.addMenuItem("第四节&nbsp;Intel&nbsp;80486微处理器总线操作时序","window.open('../chapter2/2.4.htm', '_self');");
  mm_menu_0404200259_0.addMenuItem("第五节&nbsp;Pentium&nbsp;32位微处理器","window.open('../chapter2/2.5.htm', '_self');");
   mm_menu_0404200259_0.hideOnMouseOut=true;
   mm_menu_0404200259_0.bgColor='#555555';
   mm_menu_0404200259_0.menuBorder=1;
   mm_menu_0404200259_0.menuLiteBgColor='#FFFFFF';
   mm_menu_0404200259_0.menuBorderBgColor='#777777';
window.mm_menu_0404200417_0 = new Menu("root",287,18,"",12,"#000000","#FFFFFF","#CCCCCC","#000084","left","middle",3,0,100,-5,7,true,false,true,0,true,true);
  mm_menu_0404200417_0.addMenuItem("第一节&nbsp;80486微处理器的数据类型和指令格式","window.open('../chapter3/3.1.html', '_self');");
  mm_menu_0404200417_0.addMenuItem("第二节&nbsp;寻址方式","window.open('../chapter3/3.2.htm', '_self');");
  mm_menu_0404200417_0.addMenuItem("第三节&nbsp;80486微处理器的基本指令系统","window.open('../chapter3/3.3.htm', '_self');");
  mm_menu_0404200417_0.addMenuItem("第四节&nbsp;80486微处理器的扩展指令","window.open('../chapter3/3.4.htm', '_self');");
   mm_menu_0404200417_0.hideOnMouseOut=true;
   mm_menu_0404200417_0.bgColor='#555555';
   mm_menu_0404200417_0.menuBorder=1;
   mm_menu_0404200417_0.menuLiteBgColor='#FFFFFF';
   mm_menu_0404200417_0.menuBorderBgColor='#777777';
window.mm_menu_0404200533_0 = new Menu("root",200,18,"",12,"#000000","#FFFFFF","#CCCCCC","#000084","left","middle",3,0,100,-5,7,true,false,true,0,true,true);
  mm_menu_0404200533_0.addMenuItem("第一节&nbsp;概述","window.open('../chapter4/4.1.html', '_self');");
  mm_menu_0404200533_0.addMenuItem("第二节&nbsp;宏汇编语句结构","window.open('../chapter4/4.2.htm', '_self');");
  mm_menu_0404200533_0.addMenuItem("第三节&nbsp;编语言的数据和表达式","window.open('../chapter4/4.3.htm', '_self');");
  mm_menu_0404200533_0.addMenuItem("第四节&nbsp;伪指令&nbsp;","window.open('../chapter4/4.4.htm', '_self');");
  mm_menu_0404200533_0.addMenuItem("第五节&nbsp;宏指令","window.open('../chapter4/4.5.htm', '_self');");
  mm_menu_0404200533_0.addMenuItem("第六节&nbsp;汇编语言程序设计&nbsp;","window.open('../chapter4/4.6.htm', '_self');");
  mm_menu_0404200533_0.addMenuItem("第七节&nbsp;DOS和BIOS功能调用","window.open('../chapter4/4.7.htm', '_self');");
   mm_menu_0404200533_0.hideOnMouseOut=true;
   mm_menu_0404200533_0.bgColor='#555555';
   mm_menu_0404200533_0.menuBorder=1;
   mm_menu_0404200533_0.menuLiteBgColor='#FFFFFF';
   mm_menu_0404200533_0.menuBorderBgColor='#777777';
window.mm_menu_0404200719_0 = new Menu("root",220,18,"",12,"#000000","#FFFFFF","#CCCCCC","#000084","left","middle",3,0,100,-5,7,true,false,true,0,true,true);
  mm_menu_0404200719_0.addMenuItem("第一节&nbsp;存储器的分类与性能指标&nbsp;","window.open('../chapter5/5.1.html', '_self');");
  mm_menu_0404200719_0.addMenuItem("第二节&nbsp;只读存储器","window.open('../chapter5/5.2.htm', '_self');");
  mm_menu_0404200719_0.addMenuItem("第三节&nbsp;随机存取存储器","window.open('../chapter5/5.3.htm', '_self');");
  mm_menu_0404200719_0.addMenuItem("第四节&nbsp;存储器的扩展设计","window.open('../chapter5/5.4.htm', '_self');");
  mm_menu_0404200719_0.addMenuItem("第五节&nbsp;高速缓冲存储器","window.open('../chapter5/5.5.htm', '_self');");
  mm_menu_0404200719_0.addMenuItem("第六节&nbsp;虚拟存储器及其管理技术","window.open('../chapter5/5.6.htm', '_self');");
  mm_menu_0404200719_0.addMenuItem("第七节&nbsp;存储器管理模式","window.open('../chapter5/5.7.htm', '_self');");
   mm_menu_0404200719_0.hideOnMouseOut=true;
   mm_menu_0404200719_0.bgColor='#555555';
   mm_menu_0404200719_0.menuBorder=1;
   mm_menu_0404200719_0.menuLiteBgColor='#FFFFFF';
   mm_menu_0404200719_0.menuBorderBgColor='#777777';

mm_menu_0404200719_0.writeMenus();
} // mmLoadMenus()

function MM_preloadImages() { //v3.0
  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)
    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}
}

function MM_findObj(n, d) { //v4.01
  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {
    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}
  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];
  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);
  if(!x && d.getElementById) x=d.getElementById(n); return x;
}

function MM_nbGroup(event, grpName) { //v6.0
  var i,img,nbArr,args=MM_nbGroup.arguments;
  if (event == "init" && args.length > 2) {
    if ((img = MM_findObj(args[2])) != null && !img.MM_init) {
      img.MM_init = true; img.MM_up = args[3]; img.MM_dn = img.src;
      if ((nbArr = document[grpName]) == null) nbArr = document[grpName] = new Array();
      nbArr[nbArr.length] = img;
      for (i=4; i < args.length-1; i+=2) if ((img = MM_findObj(args[i])) != null) {
        if (!img.MM_up) img.MM_up = img.src;
        img.src = img.MM_dn = args[i+1];
        nbArr[nbArr.length] = img;
    } }
  } else if (event == "over") {
    document.MM_nbOver = nbArr = new Array();
    for (i=1; i < args.length-1; i+=3) if ((img = MM_findObj(args[i])) != null) {
      if (!img.MM_up) img.MM_up = img.src;
      img.src = (img.MM_dn && args[i+2]) ? args[i+2] : ((args[i+1])? args[i+1] : img.MM_up);
      nbArr[nbArr.length] = img;
    }
  } else if (event == "out" ) {
    for (i=0; i < document.MM_nbOver.length; i++) {
      img = document.MM_nbOver[i]; img.src = (img.MM_dn) ? img.MM_dn : img.MM_up; }
  } else if (event == "down") {
    nbArr = document[grpName];
    if (nbArr)
      for (i=0; i < nbArr.length; i++) { img=nbArr[i]; img.src = img.MM_up; img.MM_dn = 0; }
    document[grpName] = nbArr = new Array();
    for (i=2; i < args.length-1; i+=2) if ((img = MM_findObj(args[i])) != null) {
      if (!img.MM_up) img.MM_up = img.src;
      img.src = img.MM_dn = (args[i+1])? args[i+1] : img.MM_up;
      nbArr[nbArr.length] = img;
  } }
}

function MM_swapImgRestore() { //v3.0
  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}

⌨️ 快捷键说明

复制代码 Ctrl + C
搜索代码 Ctrl + F
全屏模式 F11
切换主题 Ctrl + Shift + D
显示快捷键 ?
增大字号 Ctrl + =
减小字号 Ctrl + -