📄 00570.html
字号:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN">
<html>
<head>
<title>7.4 对logic和bit类型的操作</title>
<meta http-equiv="Content-Type" content="text/html; charset=GB2312" />
<meta name="generator" content="Doc-O-Matic" />
<meta http-equiv="Content-Style-Type" content="text/css" />
<link rel="STYLESHEET" href="default.css" type="text/css" />
<script type="text/javascript" src="scripts.js"></script>
</head>
<body class="Element700" onload="onBodyLoadEx('systemverilog31a.html', 'topic', '00570.html');" onmousedown="onBodyMouseDown();">
<!-- Begin Popups -->
<div class="Element801" id="popup00122">
<div class="Element800">
<div class="Element14">
链接</div>
<div class="Element11">
<div class="Element10">
<a href="00860.html" target="topic">第七章 操作符与表达式</a></div>
</div>
</div>
</div>
<!-- End Popups -->
<!-- Begin Page Header -->
<div class="Element710" id="areafixed">
<div class="Element92">
<table width="100%" cellspacing="0" cellpadding="0">
<tr><td width="33%">
<div class="Element1">
<a href="#" onmousedown="showPopup(this, 'popup00122');"><img src="seealsolink.png" border="0" alt="" title=""></a> SystemVerilog 3.1a语言参考手册</div>
</td><td width="34%">
<div class="Element2">
</div>
</td><td width="33%">
<div class="Element90">
<a href="00569.html" target="topic"><img src="btn_prev_lightblue.gif" border="0" alt="Previous" title="Previous" onmouseover="switchImage(this, 'btn_prev_lightblue_hover.gif');" onmouseout="switchImage(this, 'btn_prev_lightblue.gif');"></a><a href="00860.html" target="topic"><img src="btn_up_lightblue.gif" border="0" alt="Up" title="Up" onmouseover="switchImage(this, 'btn_up_lightblue_hover.gif');" onmouseout="switchImage(this, 'btn_up_lightblue.gif');"></a><a href="00571.html" target="topic"><img src="btn_next_lightblue.gif" border="0" alt="Next" title="Next" onmouseover="switchImage(this, 'btn_next_lightblue_hover.gif');" onmouseout="switchImage(this, 'btn_next_lightblue.gif');"></a></div>
</td></tr></table><div class="Element5">
7.4 对logic和bit类型的操作</div>
</div>
</div>
<!-- End Page Header -->
<!-- Begin Client Area -->
<div class="Element720" id="areascroll">
<div class="Element721">
<!-- Begin Page Content -->
<div class="Element58">
<a name="描述"></a><div class="Element11">
<div class="Element10">
<p class="Element10">
当一个二元操作符包含一个<span style="color: #0000FF">bit</span>类型的操作数和一个<span style="color: #0000FF">logic</span>类型的操作数的时候，结果的数据类型是<span style="color: #0000FF">logic</span>。如果一个操作数的类型是<span style="color: #0000FF">int</span>而另一个操作数的类型是<span style="color: #0000FF">integer</span>的时候，那么结果的数据类型是<span style="color: #0000FF">integer</span>。 </p>
<p class="Element10">
</p>
<p class="Element10">
对于<span style="color: #800080">!=</span>和<span style="color: #800080">==</span>操作符，如果任何一个操作数包含<span style="color: #FF0000">X</span>或<span style="color: #FF0000">Z</span>，那么就像Verilog-2001一样，返回一个<span style="color: #FF0000">X</span>。如果结果被转换成<span style="color: #0000FF">bit</span>类型（例如在一个<span style="color: #0000FF">if</span>语句中），那么结果被转换成<span style="color: #FF0000">0</span>。 </p>
<p class="Element10">
</p>
<p class="Element10">
一元缩减操作符（<span style="color: #800080">& ~& | ~| ^ ~^</span>）可以应用于任何整数类型（包括压缩数组）。如果压缩类型是一个四态类型，那么操作符应该返回类型为<span style="color: #0000FF">logic</span>的值；如果压缩类型是一个两态类型，那么返回值的类型是<span style="color: #0000FF">bit</span>。 </p><div class="Element170">
<a href="#" onclick="CopyElementToClipboard('code00213');">Copy Code</a></div>
<div class="Element13"><div class="Element12" id="code00213"><pre class="Element12"><span style="color: #0000FF">int</span> i<span style="color: #800080">;</span>
<span style="color: #0000FF">bit</span> b <span style="color: #800080">= &</span>i<span style="color: #800080">;</span>
<span style="color: #0000FF">integer</span> j<span style="color: #800080">;</span>
<span style="color: #0000FF">logic</span> c <span style="color: #800080">= &</span>j<span style="color: #800080">;</span></pre></div></div>
</div>
</div>
<a name="Group"></a><div class="Element14">
<a onclick="toggleVisibilityStored('Group');" class="a_Element14"><img src="sectionminus.png" border="0" alt="" title="" id="imgGroup">Group</a></div>
<div id="divGroup">
<div class="Element11">
<div class="Element10">
<p class="Element10">
<a href="00860.html" target="topic">第七章 操作符与表达式</a></p></div>
</div>
</div>
<a name="Links"></a><div class="Element14">
<a onclick="toggleVisibilityStored('链接');" class="a_Element14"><img src="sectionminus.png" border="0" alt="" title="" id="img链接">链接</a></div>
<div id="div链接">
<div class="Element11">
<div class="Element10">
<a href="00860.html" target="topic">第七章 操作符与表达式</a></div>
</div>
</div>
</div>
<!-- End Page Content -->
<!-- Begin Page Footer -->
<hr width="98%" align="center" size="1" color="#CCCCCC" />
<table align="center" cellpadding="0" cellspacing="0" border="0">
<tbody>
<tr height="10">
<td></td>
</tr>
<tr align="center">
<td>
<script type="text/javascript"><!--
google_ad_client = "pub-5266859600380184";
google_ad_width = 468;
google_ad_height = 60;
google_ad_format = "468x60_as";
google_ad_type = "text_image";
google_ad_channel ="";
google_page_url = document.location;
//--></script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script>
</td>
</tr>
<tr height="15">
<td></td>
</tr>
<tr align="center">
<td>
<font size=2>除非特别声明，原文版权归作者所有，如有转摘请注明原作者以及译者（<a href="http://www.fpgatech.net/" target="_blank">FPGA技术网</a>）信息。<br />
如果您对本主题有何建议或意见，请登陆<a href="http://www.fpgatech.net/forum/forumdisplay.php?fid=18" target="_blank">FPGA开发者家园</a>提交，您的参与是我们前进的动力。</font>
<script language="javascript" type="text/javascript" src="http://js.users.51.la/195685.js"></script>
<noscript><a href="http://www.51.la/?195685" target="_blank"><img alt="我要啦免费统计" src="http://img.users.51.la/195685.asp" style="border:none" /></a></noscript>
</td>
</tr>
</tbody>
</table>
<!-- End Page Footer -->
</div>
</div>
<!-- End Client Area -->
</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 + -