⭐ 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
📤 上传资源

📄 00243.html

📁 这是一本关于verilog编程语言的教程,对学习verilog语言有帮助
💻 HTML
字号:
🔍 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN">
<html>
<head>
<title>2.8 结构体文本</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', '00243.html');" onmousedown="onBodyMouseDown();">

<!-- Begin Popups -->
<div class="Element801" id="popup00009">
<div class="Element800">
<div class="Element14">
链接</div>
<div class="Element11">
<div class="Element10">
<a href="00857.html" target="topic">第二章 文本值</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, 'popup00009');"><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="00242.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="00857.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="00863.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">
2.8 结构体文本</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">
结构体文本在语法上类似于C语言的初始化设置。结构体文本必须具有一个类型，无论是通过上下文关联还是通过强制类型转换。 </p><div class="Element170">
<a href="#" onclick="CopyElementToClipboard('code00012');">Copy Code</a></div>
<div class="Element13"><div class="Element12" id="code00012"><pre class="Element12"><span style="color: #0000FF">typedef struct</span> <span style="color: #800080">{</span>
<span style="color: #0000FF">    int</span> a<span style="color: #800080">;</span>
<span style="color: #0000FF">    shortreal</span> b<span style="color: #800080">;</span>
<span style="color: #800080">}</span> ab<span style="color: #800080">;</span>

ab c<span style="color: #800080">;</span>
c <span style="color: #800080">= {</span><span style="color: #FF0000">0</span><span style="color: #800080">,</span> <span style="color: #FF0000">0.0</span><span style="color: #800080">};</span> <span style="color: #008000">// 结构体文本的类型由左侧关联文（c）确定</span></pre></div></div>
<p class="Element10">
&nbsp;</p>
<p class="Element10">
嵌套花括号必须能够反映结构体的结构，例如： </p><div class="Element170">
<a href="#" onclick="CopyElementToClipboard('code00013');">Copy Code</a></div>
<div class="Element13"><div class="Element12" id="code00013"><pre class="Element12">ab abarr<span style="color: #800080">[</span><span style="color: #FF0000">1</span><span style="color: #800080">:</span><span style="color: #FF0000">0</span><span style="color: #800080">] = {{</span><span style="color: #FF0000">1</span><span style="color: #800080">, </span><span style="color: #FF0000">1.0</span><span style="color: #800080">}, {</span><span style="color: #FF0000">2</span><span style="color: #800080">, </span><span style="color: #FF0000">2.0</span><span style="color: #800080">}};</span></pre></div></div>
<p class="Element10">
注意：C语言中可以使用的<span style="color: #800080">{</span><span style="color: #FF0000">1</span><span style="color: #800080">, </span><span style="color: #FF0000">1.0</span><span style="color: #800080">, </span><span style="color: #FF0000">2</span><span style="color: #800080">, </span><span style="color: #FF0000">2.0</span><span style="color: #800080">}</span>在SystemVerilog中是不允许使用的。&nbsp;</p>
<p class="Element10">
&nbsp;</p>
<p class="Element10">
结构体文本还可以使用成员名和值，或者是数据类型和缺省值（参见<a href="00560.html" target="topic">7.14节</a>）： </p><div class="Element170">
<a href="#" onclick="CopyElementToClipboard('code00014');">Copy Code</a></div>
<div class="Element13"><div class="Element12" id="code00014"><pre class="Element12">c <span style="color: #800080">= {</span>a<span style="color: #800080">:</span><span style="color: #FF0000">0</span><span style="color: #800080">, </span>b<span style="color: #800080">:</span><span style="color: #FF0000">0.0</span><span style="color: #800080">};</span>  <span style="color: #008000">// 成员名及成员名的值</span>
c <span style="color: #800080">= {</span><span style="color: #0000FF">default</span><span style="color: #800080">:</span><span style="color: #FF0000">0</span><span style="color: #800080">};</span>   <span style="color: #008000">// 结构体c的所有元素均被设置成0</span>
d <span style="color: #800080">=</span> ab<span style="color: #800080">'{</span><span style="color: #0000FF">int</span><span style="color: #800080">:</span><span style="color: #FF0000">1</span><span style="color: #800080">,</span> <span style="color: #0000FF">shortreal</span><span style="color: #800080">:</span><span style="color: #FF0000">1.0</span><span style="color: #800080">};</span>  <span style="color: #008000">// 数据类型以及这种类型的所有成员的缺省值</span></pre></div></div>
<p class="Element10">
&nbsp;</p>
<p class="Element10">
当一个结构体数组被初始化的时候，嵌套括号必须能够反映数组和结构体，例如： </p><div class="Element170">
<a href="#" onclick="CopyElementToClipboard('code00015');">Copy Code</a></div>
<div class="Element13"><div class="Element12" id="code00015"><pre class="Element12">ab abarr<span style="color: #800080">[</span><span style="color: #FF0000">1</span><span style="color: #800080">:</span><span style="color: #FF0000">0</span><span style="color: #800080">] = {{</span><span style="color: #FF0000">1</span><span style="color: #800080">, </span><span style="color: #FF0000">1.0</span><span style="color: #800080">}, {</span><span style="color: #FF0000">2</span><span style="color: #800080">, </span><span style="color: #FF0000">2.0</span><span style="color: #800080">}};</span></pre></div></div>
<p class="Element10">
&nbsp;</p>
<p class="Element10">
复制操作符可以用来为完全相同数目的成员设置值，复制表达式中内层括号对会被移除。 </p><div class="Element170">
<a href="#" onclick="CopyElementToClipboard('code00016');">Copy Code</a></div>
<div class="Element13"><div class="Element12" id="code00016"><pre class="Element12"><span style="color: #0000FF">struct</span> <span style="color: #800080">{</span>
<span style="color: #0000FF">    int</span> X<span style="color: #800080">,</span> Y<span style="color: #800080">,</span> X<span style="color: #800080">;</span>
<span style="color: #800080">}</span> XYZ <span style="color: #800080">= {</span><span style="color: #FF0000">3</span><span style="color: #800080">{</span><span style="color: #FF0000">1</span><span style="color: #800080">}};</span>

<span style="color: #0000FF">typedef</span> <span style="color: #0000FF">struct</span> <span style="color: #800080">{</span>
<span style="color: #0000FF">    int</span> a<span style="color: #800080">,</span> b<span style="color: #800080">[</span><span style="color: #FF0000">4</span><span style="color: #800080">];</span>
<span style="color: #800080">} </span>ab_t<span style="color: #800080">;</span>

<span style="color: #0000FF">int</span> a<span style="color: #800080">,</span> b<span style="color: #800080">,</span> c<span style="color: #800080">;</span>
ab_t v1<span style="color: #800080">[</span><span style="color: #FF0000">1</span><span style="color: #800080">:</span><span style="color: #FF0000">0</span><span style="color: #800080">][</span><span style="color: #FF0000">2</span><span style="color: #800080">:</span><span style="color: #FF0000">0</span><span style="color: #800080">];</span>
v1 <span style="color: #800080">= {</span><span style="color: #FF0000">2</span><span style="color: #800080">{{</span><span style="color: #FF0000">3</span><span style="color: #800080">{</span>a<span style="color: #800080">,{</span><span style="color: #FF0000">2</span><span style="color: #800080">{</span>b<span style="color: #800080">,</span>c<span style="color: #800080">}}}}}};</span>
    <span style="color: #008000">/* 扩展成{{3{{a,{2{b,c}}}}},{3{{a,{2{b,c}}}}}} */</span>
<span style="color: #008000">    /* 扩展成{{{a,{2{b,c}}},{a,{2{b,c}}},{a,{2{b,c}}}},</span>
<span style="color: #008000">              {{a,{2{b,c}}},{a,{2{b,c}}},{a,{2{b,c}}}}}*/</span>
<span style="color: #008000">    /* 扩展成{{{a,{b,c,b,c}},{a,{b,c,b,c}},{a,{b,c,b,c}}},</span>
<span style="color: #008000">         {{a,{b,c,b,c}},{a,{b,c,b,c}},{a,{b,c,b,c}}}}*/</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="00857.html" target="topic">第二章 文本值</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="00857.html" target="topic">第二章 文本值</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="&#x6211;&#x8981;&#x5566;&#x514D;&#x8D39;&#x7EDF;&#x8BA1;" 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 + -