📄 multacc4.htm

📁 ST20 Embedded Toolset R2.0.5用于开发基于ST20芯片机顶盒软件的开发平台,2.0.5版本,国内找不到的.在国外论坛上花了N天才找到!

💻 HTM

字号:

<html>

<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<meta name="GENERATOR" content="Quadralay WebWorks Publisher Professional Edition 6.0.5">
<meta name="TEMPLATEBASE" content="book_html">
<meta name="LASTUPDATED" content="09/01/03 09:53:18">
<title>5.3 mac and umac</title>

<STYLE TYPE="text/css">
<!--
	span.Signal { text-transform: uppercase; font-family: Verdana }
-->
</STYLE>

</head>

<body link="#3366CC" vlink="#9999CC" text="#000000" alink="#0000CC" bgcolor="#FFFFFF"
background="images/backgrnd.gif">

<p><img src="images/stlogo.gif" width="106" height="83" align="left"
alt="logo here!"> </p>

<table width="331" border="0" align="right" cellpadding="0" cellspacing="0">
  <tr>
    <td><a href="st20c1to.htm"><img src="images/navtoc.gif" width="84" height="23"
    border="0" alt="TOC"> </a></td>
    <td><a href="multacc3.htm"><img src="images/navprev.gif" width="80" height="23"
    border="0" alt="PREV"> </a></td>
    <td><a href="multacc5.htm"><img src="images/navnext.gif" width="83" height="23"
    border="0" alt="NEXT"> </a></td>
    <td><a href="st20c1ix.htm"><img src="images/navidx.gif" width="84" height="23"
    border="0" alt="INDEX"> </a></td>
  </tr>
</table>

<p><br clear="all">
</p>

<hr align="left">

<blockquote>
<h2>
  <a name="1102112"> </a><font color="#003366"  face="Verdana, Arial, Helvetica, sans-serif">5.3 	 mac and umac</font>
</h2><hr>


<p>
  <a name="1102113"> </a><font size=2  face="Verdana, Arial, Helvetica, sans-serif"><strong>mac</strong> and <strong>umac</strong> are general purpose multiply accumulate instructions, multiplying two 32-bit values and adding them to a 32-bit unsigned initial accumulator, giving a 64-bit accumulator. <strong>mac</strong> treats the multiplicands as signed and <strong>umac</strong> treats them as unsigned. Initially <span class=Signal>Areg</span> and <span class=Signal>Breg</span> hold the values to be multiplied and <span class=Signal>Creg</span> holds the initial accumulator. On completion, <span class=Signal>Areg</span> is the least significant word of the result accumulator, <span class=Signal>Breg</span> the most significant and <span class=Signal>Creg</span> holds a copy of the initial <span class=Signal>Areg</span>.</font>
</p>
</blockquote>

<hr>



<table width="331" border="0" align="left" cellpadding="0" cellspacing="0">
  <tr>
    <td><a href="st20c1to.htm"><img src="images/navtoc.gif" width="84" height="23"
    border="0" alt="TOC"> </a></td>
    <td><a href="multacc3.htm"><img src="images/navprev.gif" width="80" height="23"
    border="0" alt="PREV"> </a></td>
    <td><a href="multacc5.htm"><img src="images/navnext.gif" width="83" height="23"
    border="0" alt="NEXT"> </a></td>
    <td><a href="st20c1ix.htm"><img src="images/navidx.gif" width="84" height="23"
    border="0" alt="INDEX"> </a></td>
  </tr>
</table>
<font size=1 face="Verdana, Arial, Helvetica, sans-serif">&nbsp; &copy; 1997, 2002 STMicroelectronics. All Rights Reserved.<br>
&nbsp; ADCS 7473696A</font>
</body>
</html>

⌨️ 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 + -