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这是一本关于verilog编程语言的教程,对学习verilog语言有帮助

<span style="color: #0000FF">endclass</span>

...

send: <span style="color: #0000FF">begin</span> <span style="color: #008000">// 产生随机包并发送</span>
    <span style="color: #0000FF">byte</span> q<span style="color: #800080">[</span><span style="color: #FF0000">$</span><span style="color: #800080">];</span>
    Packet p <span style="color: #800080">=</span> <span style="color: #0000FF">new</span><span style="color: #800080">;</span>
    <span style="color: #0000FF">void</span><span style="color: #800080">'(</span>p<span style="color: #800080">.</span><span style="color: #0000FF">randomize</span><span style="color: #800080">());</span>
    q <span style="color: #800080">= {&lt;&lt;</span> <span style="color: #0000FF">byte</span><span style="color: #800080">{</span>p<span style="color: #800080">.</span>header<span style="color: #800080">,</span> p<span style="color: #800080">.</span>len<span style="color: #800080">,</span> p<span style="color: #800080">.</span>payload<span style="color: #800080">,</span> p.crc<span style="color: #800080">}};</span> <span style="color: #008000">// 压缩</span>
    stream <span style="color: #800080">=</span> <span style="color: #800080">{</span>stream<span style="color: #800080">,</span> q<span style="color: #800080">};</span>  <span style="color: #008000">// 添加到to stream</span>
<span style="color: #0000FF">end</span>

...

receive: <span style="color: #0000FF">begin</span> <span style="color: #008000">// 接收包，解压缩，并删除</span>
    <span style="color: #0000FF">byte</span> q<span style="color: #800080">[</span><span style="color: #FF0000">$</span><span style="color: #800080">];</span>
    Packet p <span style="color: #800080">=</span> <span style="color: #0000FF">new</span><span style="color: #800080">;</span>
    <span style="color: #800080">{&lt;&lt;</span> <span style="color: #0000FF">byte</span><span style="color: #800080">{</span>p<span style="color: #800080">.</span>header<span style="color: #800080">,</span> p<span style="color: #800080">.</span>len<span style="color: #800080">,</span> p<span style="color: #800080">.</span>payload <span style="color: #0000FF">with</span><span style="color: #800080">[</span><span style="color: #FF0000">0</span><span style="color: #800080">+:</span>p<span style="color: #800080">.</span>len<span style="color: #800080">],</span> p.crc<span style="color: #800080">}}</span> <span style="color: #800080">=</span> stream<span style="color: #800080">;</span>
    stream <span style="color: #800080">=</span> stream<span style="color: #800080">[</span><span style="color: #0000FF">$bits</span><span style="color: #800080">(</span>p<span style="color: #800080">)/</span><span style="color: #FF0000">8</span><span style="color: #800080">:</span><span style="color: #FF0000">$</span><span style="color: #800080">];</span> <span style="color: #008000">// 删除包</span>
<span style="color: #0000FF">end</span></pre></div></div>
<p class="Element10">
在上面的例子中，压缩操作也可以写成： </p><div class="Element170">
<a href="#" onclick="CopyElementToClipboard('code00250');">Copy Code</a></div>
<div class="Element13"><div class="Element12" id="code00250"><pre class="Element12">q <span style="color: #800080">= {&lt;&lt;</span> <span style="color: #0000FF">byte</span><span style="color: #800080">{</span>p<span style="color: #800080">.</span>header<span style="color: #800080">,</span> p<span style="color: #800080">.</span>len<span style="color: #800080">,</span> p<span style="color: #800080">.</span>payload <span style="color: #0000FF">with</span><span style="color: #800080">[</span><span style="color: #FF0000">0</span><span style="color: #800080">+:</span>p<span style="color: #800080">.</span>len<span style="color: #800080">],</span> p.crc<span style="color: #800080">}};</span></pre></div></div>
<p class="Element10">
或者写成： </p><div class="Element170">
<a href="#" onclick="CopyElementToClipboard('code00251');">Copy Code</a></div>
<div class="Element13"><div class="Element12" id="code00251"><pre class="Element12">q <span style="color: #800080">= {&lt;&lt;</span> <span style="color: #0000FF">byte</span><span style="color: #800080">{</span>p<span style="color: #800080">.</span>header<span style="color: #800080">,</span> p<span style="color: #800080">.</span>len<span style="color: #800080">,</span> p<span style="color: #800080">.</span>payload <span style="color: #0000FF">with</span><span style="color: #800080">[</span><span style="color: #FF0000">0</span><span style="color: #800080">:</span>p<span style="color: #800080">.</span>len<span style="color: #800080">-</span><span style="color: #FF0000">1</span><span style="color: #800080">],</span> p.crc<span style="color: #800080">}};</span></pre></div></div>
<p class="Element10">
或者写成： </p><div class="Element170">
<a href="#" onclick="CopyElementToClipboard('code00252');">Copy Code</a></div>
<div class="Element13"><div class="Element12" id="code00252"><pre class="Element12">q <span style="color: #800080">= {&lt;&lt;</span> <span style="color: #0000FF">byte</span><span style="color: #800080">{</span>p<span style="color: #800080">}};</span></pre></div></div>
<p class="Element10">
这几种情况的操作结果是相同的，因为<i>p<span style="color: #800080">.</span>len</i>通过约束被指定成<i>p<span style="color: #800080">.</span>payload</i>的尺寸。</p></div>
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<a href="00564.html" target="topic">7.18 流操作符（压缩/非压缩）</a></p></div>
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