<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta charset="utf-8">
<meta name="generator" content="pdf2htmlEX">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<link rel="stylesheet" href="https://static.pudn.com/base/css/base.min.css">
<link rel="stylesheet" href="https://static.pudn.com/base/css/fancy.min.css">
<link rel="stylesheet" href="https://static.pudn.com/prod/directory_preview_static/626b22d11e41a87e8a848635/raw.css">
<script src="https://static.pudn.com/base/js/compatibility.min.js"></script>
<script src="https://static.pudn.com/base/js/pdf2htmlEX.min.js"></script>
<script>
try{
pdf2htmlEX.defaultViewer = new pdf2htmlEX.Viewer({});
}catch(e){}
</script>
<title></title>
</head>
<body>
<div id="sidebar" style="display: none">
<div id="outline">
</div>
</div>
<div id="pf1" class="pf w0 h0" data-page-no="1"><div class="pc pc1 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/626b22d11e41a87e8a848635/bg1.jpg"><div class="c x0 y1 w2 h2"><div class="t m0 x1 h3 y2 ff1 fs0 fc0 sc0 ls0 ws0">先记下来：</div><div class="t m0 x1 h3 y3 ff2 fs0 fc0 sc0 ls0 ws0"><span class="ff1">、不使用<span class="fc1">初始化语句</span>；</span></div><div class="t m0 x1 h3 y4 ff2 fs0 fc0 sc0 ls0 ws0"><span class="ff1">、不使用延时语句；</span></div><div class="t m0 x1 h3 y5 ff2 fs0 fc0 sc0 ls0 ws0"><span class="ff1">、不使用循环次数不确定的语句，如：</span><span class="ff1">，</span><span class="_ _0"> </span><span class="ff1">等；</span></div><div class="t m0 x1 h3 y6 ff2 fs0 fc0 sc0 ls0 ws0"><span class="ff1">、尽量采用同步方式设计电路；</span></div><div class="t m0 x1 h3 y7 ff2 fs0 fc0 sc0 ls0 ws0"><span class="ff1">、尽量采用行为语句完成设计；</span></div><div class="t m0 x1 h3 y8 ff2 fs0 fc0 sc0 ls0 ws0"><span class="ff1">、</span><span class="_ _0"> </span><span class="ff1">过程块描述组合逻辑，应在敏感信号表中列出所有的输入信号；</span></div><div class="t m0 x1 h3 y9 ff2 fs0 fc0 sc0 ls0 ws0"><span class="ff1">、所有的内部寄存器都应该可以被复位；</span></div><div class="t m0 x1 h3 ya ff2 fs0 fc0 sc0 ls0 ws0"><span class="ff1">、用户自定义原件（</span><span class="_ _0"> </span><span class="ff1">元件）是不能被综合的。</span></div><div class="t m0 x2 h3 yb ff1 fs0 fc2 sc0 ls0 ws0">一：基本</div><div class="t m0 x2 h3 yc ff2 fs0 fc2 sc0 ls0 ws0"><span class="_ _0"> </span><span class="ff1">中的<span class="_ _1"></span>变量有<span class="_ _1"></span>线网类<span class="_ _1"></span>型和寄<span class="_ _1"></span>存器类<span class="_ _1"></span>型。线<span class="_ _1"></span>网型变<span class="_ _1"></span>量综合<span class="_ _1"></span>成<span class="_ _2"> </span></span><span class="ff1">，而<span class="_ _1"></span>寄存器<span class="_ _1"></span>可能综<span class="_ _1"></span>合成<span class="_ _0"> </span></span><span class="_ _1"></span><span class="ff1">，锁<span class="_ _1"></span>存器和<span class="_ _1"></span>触发器<span class="_ _1"></span>，</span></div><div class="t m0 x2 h3 yd ff1 fs0 fc2 sc0 ls0 ws0">还有可能被优化掉。</div><div class="t m0 x2 h3 ye ff1 fs0 fc2 sc0 ls0 ws0">二：<span class="ff2"><span class="_ _0"> </span></span>语句结构到门级的映射</div><div class="t m0 x2 h3 yf ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、连续性赋值：</span></div><div class="t m0 x2 h3 y10 ff1 fs0 fc2 sc0 ls0 ws0">连续性赋值语<span class="_ _1"></span>句逻辑结构上<span class="_ _1"></span>就是将等式右<span class="_ _1"></span>边的驱动左边<span class="_ _1"></span>的结点。因此<span class="_ _1"></span>连续性赋值的<span class="_ _1"></span>目标结点总是<span class="_ _1"></span>综合成由组合<span class="_ _1"></span>逻辑驱</div><div class="t m0 x2 h3 y11 ff1 fs0 fc2 sc0 ls0 ws0">动的结点。<span class="ff2"><span class="_ _0"> </span></span>语句中的延时综合时都将忽视。</div><div class="t m0 x2 h3 y12 ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、过程性赋值：</span></div><div class="t m0 x2 h3 y13 ff1 fs0 fc2 sc0 ls0 ws0">过程性赋值只出现在<span class="_ _0"> </span><span class="ff2"><span class="_ _0"> </span></span>语句中。</div><div class="t m0 x2 h3 y14 ff1 fs0 fc2 sc0 ls0 ws0">阻塞赋值和非阻塞赋值就该赋值本身是没有区别的，只是对后面的语句有不同的影响。</div><div class="t m0 x2 h3 y15 ff1 fs0 fc2 sc0 ls0 ws0">建议设计组合逻辑电路时用阻塞赋值，设计时序电路时用非阻塞赋值。</div><div class="t m0 x2 h3 y16 ff1 fs0 fc2 sc0 ls0 ws0">过程性<span class="_ _1"></span>赋值的<span class="_ _1"></span>赋值对<span class="_ _1"></span>象有可<span class="_ _1"></span>能综合<span class="_ _1"></span>成<span class="_ _3"> </span><span class="ff2"> !"# <span class="_ _1"></span></span>和<span class="_ _0"> </span><span class="ff2">$%&$%</span>，<span class="_ _1"></span>取决于<span class="_ _1"></span>具体状<span class="_ _1"></span>况。如<span class="_ _1"></span>，时钟<span class="_ _1"></span>控制下<span class="_ _1"></span>的非阻<span class="_ _1"></span>塞赋值<span class="_ _1"></span>综合</div><div class="t m0 x2 h3 y17 ff1 fs0 fc2 sc0 ls0 ws0">成<span class="_ _0"> </span><span class="ff2">$%&$%</span>。</div><div class="t m0 x2 h3 y18 ff1 fs0 fc2 sc0 ls0 ws0">过程性赋值语句中的任何延时在综合时都将忽略。</div><div class="t m0 x2 h3 y19 ff1 fs0 fc2 sc0 ls0 ws0">建议同一个变量单一地使用阻塞或者非阻塞赋值。</div><div class="t m0 x2 h3 y1a ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、逻辑操作符：</span></div><div class="t m0 x2 h3 y1b ff1 fs0 fc2 sc0 ls0 ws0">逻辑操作符对应于硬件中已有的逻辑门，一些操作符不能被综合：<span class="ff2">'''</span>、<span class="ff2">(''</span>。</div><div class="t m0 x2 h3 y1c ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、算术操作符：</span></div><div class="t m0 x2 h3 y1d ff2 fs0 fc2 sc0 ls0 ws0"><span class="_ _0"> </span><span class="ff1">中将<span class="_ _0"> </span></span><span class="_ _0"> </span><span class="ff1">视<span class="_ _1"></span>为无符<span class="_ _1"></span>号数，<span class="_ _1"></span>而<span class="_ _0"> </span></span><span class="_ _1"></span>"<span class="_ _0"> </span><span class="ff1">视为有<span class="_ _1"></span>符号数<span class="_ _1"></span>。因此<span class="_ _1"></span>，进行<span class="_ _1"></span>有符号<span class="_ _1"></span>操作时<span class="_ _1"></span>使用<span class="_ _3"> </span></span>" <span class="ff1">使用<span class="_ _1"></span>无符号<span class="_ _1"></span>操作</span></div><div class="t m0 x2 h3 y1e ff1 fs0 fc2 sc0 ls0 ws0">时使用<span class="_ _0"> </span><span class="ff2"></span>。</div><div class="t m0 x2 h3 y1f ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、进位：</span></div><div class="t m0 x2 h3 y20 ff1 fs0 fc2 sc0 ls0 ws0">通常会将进行运算操作的结果比原操作数扩展一位，用来存放进位或者借位。如：</div><div class="t m0 x2 h4 y21 ff2 fs0 fc2 sc0 ls0 ws0">!)*+,! -.</div><div class="t m0 x2 h4 y22 ff2 fs0 fc2 sc0 ls0 ws0">!)*+,!/.</div><div class="t m0 x2 h4 y23 ff2 fs0 fc2 sc0 ls0 ws0">!/'0-.</div><div class="t m0 x2 h3 y24 ff2 fs0 fc2 sc0 ls0 ws0">/<span class="_ _0"> </span><span class="ff1">的最高位用来存放进位。</span></div><div class="t m0 x2 h3 y25 ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、关系运算符：</span></div><div class="t m0 x2 h3 y26 ff1 fs0 fc2 sc0 ls0 ws0">关系运算符：<span class="ff2">1 2 1' 2'</span></div><div class="t m0 x2 h3 y27 ff1 fs0 fc2 sc0 ls0 ws0">和算术操作符一样，可以进行有符号和无符号运算，取决于数据类型是<span class="_ _0"> </span><span class="ff2"></span>，<span class="ff2">"<span class="_ _0"> </span></span>还是<span class="_ _0"> </span><span class="ff2">"</span>。</div><div class="t m0 x2 h3 y28 ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、相等运算符：</span>''<span class="ff1">，！</span>'</div><div class="t m0 x2 h3 y29 ff1 fs0 fc2 sc0 ls0 ws0">注意：<span class="ff2">'''</span>和！<span class="ff2">''</span>是不可综合的。</div><div class="t m0 x2 h3 y2a ff1 fs0 fc2 sc0 ls0 ws0">可以进行有符号或无符号操作，取决于数据类型</div><div class="t m0 x2 h3 y2b ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、移位运算符：</span></div><div class="t m0 x2 h3 y2c ff1 fs0 fc2 sc0 ls0 ws0">左移，右移，右边操作数可以是常数或者是变量，二者综合出来的结果不同。</div><div class="t m0 x2 h3 y2d ff2 fs0 fc2 sc0 ls0 ws0">3<span class="ff1">、部分选择：</span></div><div class="t m0 x2 h3 y2e ff1 fs0 fc2 sc0 ls0 ws0">部分选择索引必须是常量。</div><div class="t m0 x2 h3 y2f ff2 fs0 fc2 sc0 ls0 ws0">+<span class="ff1">、</span>-4<span class="_ _0"> </span><span class="ff1">选择：</span></div><div class="t m0 x2 h3 y30 ff2 fs0 fc2 sc0 ls0 ws0">-4<span class="_ _0"> </span><span class="ff1">选择中的索引可以用变量，这样将综合成多路（复用）器。</span></div><div class="t m0 x2 h3 y31 ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、敏感表：<span class="_ _1"></span></span><span class="_ _0"> </span><span class="ff1">过程中，<span class="_ _1"></span>所有被读取的<span class="_ _1"></span>数据，即等号<span class="_ _1"></span>右边的变量都<span class="_ _1"></span>要应放在敏感<span class="_ _1"></span>表中，不然，<span class="_ _1"></span>综合时不能正<span class="_ _1"></span>确</span></div></div><div class="t m0 x3 h5 y32 ff3 fs1 fc3 sc0 ls0 ws0">1</div></div><div class="pi" data-data='{"ctm":[1.611850,0.000000,0.000000,1.611850,0.000000,0.000000]}'></div></div>
</body>
</html>
<div id="pf2" class="pf w0 h0" data-page-no="2"><div class="pc pc2 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/626b22d11e41a87e8a848635/bg2.jpg"><div class="c x0 y1 w2 h2"><div class="t m0 x2 h3 y2 ff1 fs0 fc2 sc0 ls0 ws0">地映射到所用的门。</div><div class="t m0 x2 h3 y3 ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、</span>5<span class="ff1">：</span></div><div class="t m0 x2 h3 y4 ff1 fs0 fc2 sc0 ls0 ws0">如果变量没有在<span class="_ _0"> </span><span class="ff2">5<span class="_ _0"> </span></span>语句的每个分支中进行赋值，将会产生<span class="_ _3"> </span><span class="ff2">"#</span>。如果<span class="_ _0"> </span><span class="ff2">5<span class="_ _0"> </span></span>语句中产生了<span class="_ _0"> </span><span class="ff2">"#</span>，则<span class="_ _0"> </span><span class="ff2">5<span class="_ _0"> </span></span>的条件中最好不</div><div class="t m0 x2 h3 y5 ff1 fs0 fc2 sc0 ls0 ws0">要用到算术操作。<span class="ff2">/<span class="_ _0"> </span></span>语句类似。<span class="ff2">/<span class="_ _0"> </span></span>的条款可以是变量。</div><div class="t m0 x2 h3 y6 ff1 fs0 fc2 sc0 ls0 ws0">如果一个变量在同一个<span class="_ _0"> </span><span class="ff2">5<span class="_ _0"> </span></span>条件分支中先赎值然后读取，则不会产生<span class="_ _0"> </span><span class="ff2">"<span class="_ _4"></span>#<span class="ff1">。如果先读取，后赎值，则会产生<span class="_ _0"> </span></span>"#<span class="ff1">。</span></span></div><div class="t m0 x2 h3 y7 ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、循环：</span></div><div class="t m0 x2 h3 y8 ff1 fs0 fc2 sc0 ls0 ws0">只有<span class="_ _0"> </span><span class="ff2">&%<span class="_ _0"> </span></span>语句是可以综合的。</div><div class="t m0 x2 h3 y9 ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、设计时序电<span class="_ _1"></span>路时，建议<span class="_ _5"></span>变量在<span class="_ _0"> </span></span><span class="_ _0"> </span><span class="ff1">语<span class="_ _1"></span>句中赋值<span class="_ _1"></span>，而在该<span class="_ _0"> </span></span><span class="_ _2"> </span><span class="ff1">语句外使用<span class="_ _1"></span>，使综<span class="_ _1"></span>合时能准确地<span class="_ _1"></span>匹配。建议</span></div><div class="t m0 x2 h3 ya ff1 fs0 fc2 sc0 ls0 ws0">不要使用局部变量。</div><div class="t m0 x2 h3 yb ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、不能在多个<span class="_ _0"> </span></span><span class="_ _0"> </span><span class="ff1">块中对同一个变量赎值</span></div><div class="t m0 x2 h3 yc ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、函数</span></div><div class="t m0 x2 h3 yd ff1 fs0 fc2 sc0 ls0 ws0">函数代表一个组合逻辑，所有内部定义的变量都是临时的，这些变量综合后为<span class="_ _0"> </span><span class="ff2"></span>。</div><div class="t m0 x2 h3 ye ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、任务：</span></div><div class="t m0 x2 h3 yf ff1 fs0 fc2 sc0 ls0 ws0">任务可能是组合逻辑或者时序逻辑，取决于何种情况下调用任务。</div><div class="t m0 x2 h3 y10 ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、</span>6<span class="ff1">：</span></div><div class="t m0 x2 h3 y11 ff2 fs0 fc2 sc0 ls0 ws0">6<span class="_ _0"> </span><span class="ff1">会综合成一个三态门，必须在条件语句中赋值</span></div><div class="t m0 x2 h3 y12 ff2 fs0 fc2 sc0 ls0 ws0">3<span class="ff1">、参数化设计：</span></div><div class="t m0 x2 h3 y13 ff1 fs0 fc2 sc0 ls0 ws0">优点：参数可重载，不需要多次定义模块</div><div class="t m0 x2 h3 y14 ff1 fs0 fc2 sc0 ls0 ws0">四：模块优化</div><div class="t m0 x2 h3 y15 ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、资源共享：</span></div><div class="t m0 x2 h6 y16 ff1 fs0 fc2 sc0 ls0 ws0">当进<span class="_ _1"></span>程<span class="_ _1"></span>涉及<span class="_ _1"></span>到<span class="_ _1"></span>共用<span class="_ _2"> </span><span class="ff2">7<span class="_ _2"> </span></span>时，<span class="_ _1"></span>要<span class="_ _1"></span>考<span class="_ _1"></span><span class="ff4">虑</span>资<span class="_ _1"></span>源<span class="_ _1"></span>分配<span class="_ _1"></span><span class="ff4">问<span class="_ _1"></span>题</span>。<span class="_ _1"></span>可<span class="_ _1"></span>以共<span class="_ _1"></span>享<span class="_ _1"></span>的操<span class="_ _1"></span>作<span class="_ _1"></span>符<span class="_ _1"></span><span class="ff4">主</span>要<span class="_ _1"></span>有<span class="_ _1"></span>：关<span class="_ _1"></span>系<span class="_ _1"></span>操作<span class="_ _1"></span>符<span class="_ _1"></span>、<span class="_ _1"></span><span class="ff4">加减<span class="_ _1"></span>乘<span class="_ _1"></span>除<span class="_ _1"></span></span>操作<span class="_ _1"></span>符<span class="_ _1"></span>。通<span class="_ _1"></span>常</div><div class="t m0 x2 h6 y17 ff4 fs0 fc2 sc0 ls0 ws0">乘<span class="ff1">和</span>加<span class="ff1">不共用<span class="_ _0"> </span><span class="ff2">7</span>，</span>乘除<span class="ff1">通常在</span>其<span class="ff1">内部共用。</span></div><div class="t m0 x2 h6 y18 ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、共用表<span class="ff4">达</span>式：</span></div><div class="t m0 x2 h3 y19 ff1 fs0 fc2 sc0 ls0 ws0">如：<span class="ff2">/'0-.</span></div><div class="t m0 x2 h4 y33 ff2 fs0 fc2 sc0 ls0 ws0">8!8!'90:0-;.</div><div class="t m0 x2 h6 y1b ff4 fs0 fc2 sc0 ls0 ws0">两<span class="ff1">者</span>虽<span class="ff1">然有共用的</span>Ａ＋Ｂ<span class="ff1">，</span>但<span class="ff1">是有些综合</span>工<span class="ff1">具不能</span>识<span class="ff1">别</span>．<span class="ff1">可以将</span>第<span class="ff1">二句</span>改<span class="ff1">为：<span class="ff2">'90/</span>；这样只需</span>两<span class="ff1">个</span>加法<span class="ff1">器</span>．</div><div class="t m0 x2 h6 y1c ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、<span class="ff4">转</span>移代<span class="ff4">码</span>：</span></div><div class="t m0 x2 h6 y1d ff1 fs0 fc2 sc0 ls0 ws0">如循环语句中没有发生变化的语句移出循环<span class="ff4">．</span></div><div class="t m0 x2 h6 y1e ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">、<span class="ff4">避免<span class="_ _0"> </span></span></span>"#<span class="ff1">：</span></div><div class="t m0 x2 h6 y1f ff4 fs0 fc2 sc0 ls0 ws0">两<span class="ff1">种方</span>法<span class="ff1">：<span class="ff2"></span>、在每一个<span class="_ _0"> </span><span class="ff2">5<span class="_ _0"> </span></span>分支中对变量赋值。<span class="ff2"></span>、<span class="fc4">在每一个<span class="_ _0"> </span><span class="ff2">5<span class="_ _0"> </span></span>语句中都对变量赋初值</span>。</span></div><div class="t m0 x2 h3 y20 ff2 fs0 fc2 sc0 ls0 ws0"><span class="ff1">：模块：</span></div><div class="t m0 x2 h6 y34 ff1 fs0 fc2 sc0 ls0 ws0">综合生成的存<span class="ff4">储</span>器如<span class="_ _0"> </span><span class="ff2"><=<span class="_ _0"> </span></span>或<span class="_ _0"> </span><span class="ff2"><span class="_ _4"></span>=<span class="_ _0"> </span><span class="ff1">不是一种好方<span class="ff4">法</span>，只是成<span class="ff4">堆</span>的寄存器，<span class="ff4">很费</span>资源。最好用<span class="ff4">库</span>自<span class="ff4">带</span>的存<span class="ff4">储</span>器模块。</span></span></div><div class="t m0 x2 h6 y35 ff4 fs0 fc2 sc0 ls0 ws0">五<span class="ff1">、</span><span class="fc5 sc1">验证</span><span class="ff1">：</span></div><div class="t m0 x2 h6 y36 ff4 fs0 fc2 sc0 ls0 ws0">１<span class="ff1">、敏感表：</span></div><div class="t m0 x2 h6 y24 ff1 fs0 fc2 sc0 ls0 ws0">在<span class="_ _0"> </span><span class="ff2"><span class="_ _0"> </span></span>语句中，如果敏感表不<span class="ff4">含</span>时钟，最好将所有的被读取的信号都放在敏感表中。</div><div class="t m0 x2 h6 y25 ff4 fs0 fc2 sc0 ls0 ws0">２<span class="ff1">、</span>异<span class="ff1">步复位：</span></div><div class="t m0 x2 h6 y26 ff1 fs0 fc2 sc0 ls0 ws0">建议不要在<span class="ff4">异</span>步时对变量读取，即<span class="ff4">异</span>步复位时，对信号赋以常数值。</div><div class="t m0 x2 h4 y37 ff2 fs0 fc3 sc0 ls0 ws0"><span class="ff5 fc5">verilog</span></div></div><div class="c x4 y38 w3 h7"><div class="t m0 x0 h8 y39 ff5 fs0 fc5 sc0 ls0 ws0"> <span class="_ _6"></span> </div></div><div class="c x0 y1 w2 h2"><div class="t m0 x5 h6 y37 ff1 fs0 fc3 sc0 ls0 ws0">的<span class="ff4">流</span>行<span class="ff2"> </span>有<span class="ff4">两</span>方面的原因<span class="ff2">.</span></div><div class="t m0 x2 h6 y3a ff2 fs0 fc3 sc0 ls0 ws0">-!<span class="_ _0"> </span><span class="ff4">与<span class="_ _0"> </span><span class="ff5 fc5">VHDL</span></span></div></div><div class="c x6 y3b w3 h7"><div class="t m0 x0 h8 y39 ff5 fs0 fc5 sc0 ls0 ws0"> <span class="_ _6"></span> </div></div><div class="c x0 y1 w2 h2"><div class="t m0 x7 h3 y3a ff1 fs0 fc3 sc0 ls0 ws0">相比的优点</div><div class="t m0 x2 h6 y3c ff2 fs0 fc3 sc0 ls0 ws0">/<span class="_ _0"> </span><span class="ff4">典<span class="ff1">型的<span class="_ _0"> </span></span></span><span class="_ _0"> </span><span class="ff1">模块</span></div><div class="t m0 x2 h6 y3d ff2 fs0 fc3 sc0 ls0 ws0">!<span class="_ _0"> </span><span class="ff1">语<span class="ff4">法</span>要点</span></div><div class="t m0 x2 h6 y3e ff2 fs0 fc3 sc0 ls0 ws0">;!<span class="_ _0"> </span><span class="ff1">的<span class="ff4">流</span>行</span> <span class="ff1">有<span class="ff4">两</span>方面的原因</span>*</div><div class="t m0 x2 h6 y3f ff2 fs0 fc3 sc0 ls0 ws0"><span class="_ _0"> </span><span class="ff4">它<span class="ff1">是<span class="_ _0"> </span></span></span>#>#<span class="_ _0"> </span><span class="ff1">的模<span class="ff4">拟</span>器<span class="_ _0"> </span></span>&?7<span class="_ _0"> </span><span class="ff1">的基<span class="ff4">础</span></span> #>#<span class="_ _0"> </span><span class="ff1">的<span class="ff4">广泛流</span>行使<span class="ff4">得<span class="_ _7"> </span></span></span><span class="_ _7"> </span><span class="ff1">在<span class="_ _0"> </span></span>3+<span class="_ _0"> </span><span class="ff4">年<span class="ff1">代</span>深<span class="ff1">入</span>人心</span>.</div><div class="t m0 x2 h6 y40 ff2 fs0 fc3 sc0 ls0 ws0"><span class="_ _7"> </span><span class="ff4">它<span class="ff1">在</span>硅谷获得广泛<span class="ff1">使用</span></span>.</div><div class="t m0 x2 h6 y41 ff2 fs0 fc3 sc0 ls0 ws0">-;!<span class="_ _7"> </span><span class="ff4">与<span class="_ _0"> </span></span>@7<span class="_ _0"> </span><span class="ff1">相比的优点二者的关系<span class="ff4">仿佛<span class="_ _0"> </span></span></span>/<span class="_ _0"> </span><span class="ff4">与<span class="_ _7"> </span></span>5<4A <span class="_ _1"></span><span class="ff1">具体而<span class="ff4">言</span></span>*</div></div><div class="t m0 x3 h5 y32 ff3 fs1 fc3 sc0 ls0 ws0">2</div><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a><a class="l" rel='nofollow' onclick='return false;'><div class="d m1"></div></a></div><div class="pi" data-data='{"ctm":[1.611850,0.000000,0.000000,1.611850,0.000000,0.000000]}'></div></div>
<div id="pf3" class="pf w0 h0" data-page-no="3"><div class="pc pc3 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/626b22d11e41a87e8a848635/bg3.jpg"><div class="c x0 y1 w2 h2"><div class="t m0 x2 h6 y2 ff2 fs0 fc3 sc0 ls0 ws0">!<span class="_ _7"> </span><span class="ff1">的代<span class="ff4">码效率更</span>高</span>*</div><div class="t m0 x2 h6 y3 ff2 fs0 fc3 sc0 ls0 ws0">8<span class="ff1">比<span class="ff4">较明显</span>的对比</span>*</div><div class="t m0 x2 h6 y4 ff2 fs0 fc3 sc0 ls0 ws0">@7<span class="_ _7"> </span><span class="ff1">在描述一个<span class="ff4">实</span>体时采用<span class="_ _0"> </span></span>""B#"#"C<span class="_ _0"> </span><span class="ff1">模式</span> </div><div class="t m0 x2 h6 y5 ff2 fs0 fc3 sc0 ls0 ws0"><span class="_ _7"> </span><span class="ff1">在描述一个<span class="ff4">实</span>体时只需用一个</span>DE>C<span class="_ _1"></span>B>CE>CD<span class="ff1">语句块</span>F</div><div class="t m0 x2 h6 y6 ff1 fs0 fc3 sc0 ls0 ws0">此外<span class="_ _7"> </span><span class="ff2"><span class="_ _0"> </span></span>的高<span class="ff4">效</span>性还在<span class="ff4">很</span>多地方体现出来<span class="ff2">.</span></div><div class="t m0 x2 h6 y7 ff2 fs0 fc3 sc0 ls0 ws0">!<span class="_ _7"> </span><span class="ff1">支<span class="ff4">持</span>二进制的<span class="ff4">加减</span>运算</span>*</div><div class="t m0 x2 h6 y8 ff2 fs0 fc3 sc0 ls0 ws0">@7<span class="_ _0"> </span><span class="ff1">在<span class="_ _5"></span>进<span class="_ _1"></span>行<span class="_ _1"></span>二<span class="_ _1"></span>进<span class="_ _1"></span>制<span class="_ _1"></span>的<span class="_ _5"></span><span class="ff4">加<span class="_ _1"></span>减<span class="_ _1"></span></span>运<span class="_ _1"></span>算<span class="_ _1"></span>时<span class="_ _1"></span>使<span class="_ _5"></span>用<span class="_ _3"> </span></span>#GHHH<span class="_ _1"></span><span class="ff1">函<span class="_ _1"></span>数<span class="_ _1"></span>或<span class="_ _1"></span>者<span class="_ _1"></span>进<span class="_ _5"></span>行<span class="_ _1"></span><span class="ff4">其<span class="_ _1"></span>他<span class="_ _1"></span></span>的<span class="_ _5"></span>定义<span class="_ _5"></span></span> <span class="_ _1"></span><span class="ff1">总<span class="_ _5"></span><span class="ff4">之<span class="_ _1"></span></span>必<span class="_ _1"></span>须<span class="_ _1"></span>通<span class="_ _1"></span><span class="ff4">知<span class="_ _1"></span>编<span class="_ _5"></span>译<span class="_ _1"></span></span>器<span class="_ _5"></span></span>.<span class="_ _2"> </span><span class="ff4">直<span class="_ _1"></span>接<span class="_ _1"></span><span class="ff1">用<span class="_ _1"></span></span>形</span></div><div class="t m0 x2 h6 y9 ff1 fs0 fc3 sc0 ls0 ws0">如<span class="ff2">D#'0ID</span>的表<span class="ff4">示</span>二进制的<span class="ff4">加减</span>运算<span class="ff2">.</span></div><div class="t m0 x2 h3 ya ff2 fs0 fc3 sc0 ls0 ws0"><span class="_ _7"> </span><span class="ff1">综合时可控制性好</span>*</div><div class="t m0 x2 h6 yb ff2 fs0 fc3 sc0 ls0 ws0">@7<span class="_ _7"> </span><span class="ff1">对信号不<span class="ff4">加</span>区分地定义为</span>DD </div><div class="t m0 x2 h3 yc ff1 fs0 fc3 sc0 ls0 ws0">而<span class="_ _7"> </span><span class="ff2"><span class="_ _0"> </span></span>区分为<span class="_ _0"> </span><span class="ff2">"<span class="_ _0"> </span></span>类型的和<span class="_ _0"> </span><span class="ff2"><span class="_ _7"> </span></span>类型的<span class="ff2">.</span></div><div class="t m0 x2 h6 yd ff4 fs0 fc3 sc0 ls0 ws0">但<span class="ff1">是</span>也<span class="ff1">有</span>人<span class="ff1">支</span>持<span class="_ _7"> </span><span class="ff2">@7 </span>认<span class="ff1">为<span class="_ _0"> </span><span class="ff2"><span class="_ _0"> </span></span>和<span class="_ _0"> </span><span class="ff2">@7<span class="_ _7"> </span></span>的关系</span>仿佛<span class="_ _0"> </span><span class="ff2">/<span class="_ _0"> </span><span class="ff1">和<span class="_ _0"> </span></span>/00F/;</span>典<span class="ff1">型的<span class="_ _0"> </span><span class="ff2"><span class="_ _0"> </span></span>模块</span></div><div class="t m0 x2 h6 ye ff4 fs0 fc3 sc0 ls0 ws0">讨论<span class="ff1">以下</span>典<span class="ff1">型电路的<span class="_ _7"> </span><span class="ff2"><span class="_ _0"> </span></span>描述<span class="ff2">*</span></span></div><div class="t m0 x2 h6 yf ff2 fs0 fc3 sc0 ls0 ws0">H<span class="ff4">与<span class="ff1">非门</span></span>.</div><div class="t m0 x2 h6 y10 ff2 fs0 fc3 sc0 ls0 ws0">H<span class="ff4">加法<span class="ff1">器</span></span>.!!BB<span class="ff1">即<span class="ff4">全加</span>器</span></div><div class="t m0 x2 h3 y11 ff2 fs0 fc3 sc0 ls0 ws0">H!<span class="_ _7"> </span><span class="ff1">触发器</span>.</div><div class="t m0 x2 h6 y12 ff2 fs0 fc3 sc0 ls0 ws0">H<span class="ff1 fc4">计数器</span>.!BBHH<span class="ff1">分<span class="ff4">频</span>的<span class="_ _7"> </span></span>#<span class="_ _1"></span>C"</div><div class="t m0 x2 h4 y42 ff2 fs0 fc3 sc0 ls0 ws0">H!"#.</div><div class="t m0 x2 h6 y14 ff2 fs0 fc3 sc0 ls0 ws0">H<span class="ff1">时序<span class="ff4">机</span></span>.</div><div class="t m0 x2 h3 y15 ff2 fs0 fc3 sc0 ls0 ws0">H<span class="fc4">=</span>.!!!BB<span class="ff1">用<span class="_ _0"> </span></span>%<span class="_ _0"> </span><span class="ff1">的</span></div><div class="t m0 x2 h3 y16 ff2 fs0 fc3 sc0 ls0 ws0">H<span class="ff1">模块引用</span>.</div><div class="t m0 x2 h6 y17 ff2 fs0 fc3 sc0 ls0 ws0">H<span class="ff4 fc4">预编译</span>.</div><div class="t m0 x2 h6 y18 ff2 fs0 fc3 sc0 ls0 ws0">H<span class="ff4">与<span class="ff1">非门的<span class="_ _7"> </span></span></span><span class="_ _0"> </span><span class="ff1">描述如下</span>*</div><div class="t m0 x2 h6 y19 ff2 fs0 fc3 sc0 ls0 ws0">BB<span class="_ _0"> </span><span class="ff1">使用和<span class="_ _7"> </span></span>/<span class="_ _0"> </span><span class="ff1">语<span class="ff4">言</span>相同的注<span class="ff4">释</span>方<span class="ff4">法</span></span></div><div class="t m0 x2 h6 y1a ff2 fs0 fc3 sc0 ls0 ws0">E>C<span class="_ _8"></span>!<span class="_ _8"></span>>+:  J;.BB<span class="_ _2"> </span><span class="ff1">一<span class="_ _2"> </span>个<span class="_ _9"> </span></span><span class="_ _9"> </span><span class="ff1">模<span class="_ _0"> </span>块<span class="_ _0"> </span>总<span class="_ _2"> </span>是<span class="_ _0"> </span>以<span class="_ _a"> </span></span>E>C<span class="_ _9"> </span><span class="ff4">开<span class="_ _7"> </span><span class="ff1">始<span class="_ _2"> </span></span></span> <span class="_ _2"> </span><span class="ff1">以<span class="_ _9"> </span></span>>E>C<span class="_ _8"></span>!<span class="_ _0"> </span>!<span class="_ _b"> </span>!<span class="_ _2"> </span><span class="ff1">结<span class="_ _2"> </span><span class="ff4">束<span class="_ _2"> </span></span></span> >+<span class="_ _9"> </span><span class="ff1">是<span class="_ _0"> </span>模<span class="_ _2"> </span>块</span></div><div class="t m0 x2 h6 y1b ff4 fs0 fc3 sc0 ls0 ws0">名<span class="ff2">   J<span class="_ _0"> </span><span class="ff1">是模块的<span class="_ _7"> </span></span><span class="_ _0"> </span><span class="ff1">个输入输出信号</span></span></div><div class="t m0 x2 h6 y1c ff2 fs0 fc3 sc0 ls0 ws0">%C"! .8!BB<span class="ff4">告诉编译<span class="ff1">器<span class="_ _0"> </span></span></span> <span class="_ _0"> </span><span class="ff1">对此模块而<span class="ff4">言</span>是输入</span> <span class="ff4">并且<span class="ff1">数据类型是</span></span>DI"D</div><div class="t m0 x2 h6 y1d ff2 fs0 fc3 sc0 ls0 ws0">C"%C"!J.8!BB<span class="ff4">告诉编译<span class="ff1">器<span class="_ _0"> </span></span></span>J<span class="_ _0"> </span><span class="ff1">对此模块而<span class="ff4">言</span>是输出</span> <span class="ff1">数据类型<span class="ff4">也</span>是</span>DI"D</div><div class="t m0 x2 h6 y1e ff2 fs0 fc3 sc0 ls0 ws0">>8!:J  ;.!BB<span class="ff4">我理解<span class="_ _0"> </span></span>><span class="_ _0"> </span><span class="ff1">是运算符</span> <span class="ff4">我们<span class="ff1">不必</span>深究<span class="_ _0"> </span></span><span class="_ _0"> </span><span class="ff1">中的正式术语是<span class="ff4">什</span></span></div><div class="t m0 x2 h6 y1f ff4 fs0 fc3 sc0 ls0 ws0">么<span class="ff1">了<span class="_ _1"></span></span>吧<span class="_ _1"></span><span class="ff1">，<span class="_ _1"></span>总<span class="_ _1"></span></span>之<span class="_ _1"></span><span class="ff1">这<span class="_ _1"></span>种<span class="_ _1"></span></span>形<span class="ff1">式<span class="_ _1"></span>表<span class="_ _1"></span></span>示<span class="_ _2"> </span><span class="ff2">J'K:<span class="_ _1"></span>!LL!<span class="_ _1"></span>;.<span class="_ _1"></span></span>你<span class="_ _1"></span><span class="ff1">一<span class="_ _1"></span>定<span class="_ _1"></span>已<span class="_ _1"></span></span>经想<span class="_ _5"></span><span class="ff1">到类<span class="_ _1"></span>似<span class="_ _1"></span>的<span class="_ _1"></span>运算<span class="_ _1"></span>符<span class="_ _1"></span>还<span class="_ _1"></span>有<span class="_ _1"></span><span class="ff2">D"D D><span class="_ _1"></span>D DD DD DMD<span class="_ _1"></span></span>了</span></div><div class="t m0 x2 h6 y20 ff4 fs0 fc3 sc0 ls0 ws0">吧<span class="ff2">.</span>除<span class="_ _1"></span><span class="ff1">了<span class="ff2">D"D <span class="_ _1"></span></span></span>括<span class="ff1">号<span class="_ _1"></span></span>里<span class="ff1">的信<span class="_ _1"></span>号数可<span class="_ _1"></span>以任意<span class="_ _5"></span><span class="ff2"> </span></span>例<span class="ff1">如<span class="_ _2"> </span><span class="ff2">8:J   ;<span class="_ _1"></span></span>表</span>示<span class="_ _0"> </span><span class="ff2">J'!<span class="_ _1"></span>NN!!NN!<span class="_ _1"></span> <span class="_ _1"></span></span>并且<span class="_ _1"></span><span class="ff1">延时是<span class="_ _2"> </span><span class="ff2"><span class="_ _0"> </span></span>个<span class="_ _1"></span>单位时<span class="_ _1"></span></span>间<span class="ff1">，<span class="_ _1"></span><span class="ff2">OM<span class="_ _0"> </span></span>表<span class="_ _1"></span></span>示<span class="ff1">延时</span></div><div class="t m0 x2 h6 y34 ff2 fs0 fc3 sc0 ls0 ws0">M<span class="_ _7"> </span><span class="ff1">个单位时<span class="ff4">间</span></span>.</div><div class="t m0 x2 h4 y22 ff2 fs0 fc3 sc0 ls0 ws0">>E>C</div><div class="t m0 x2 h6 y43 ff2 fs0 fc3 sc0 ls0 ws0">H<span class="ff4">加法<span class="ff1">器的<span class="_ _7"> </span></span></span><span class="_ _0"> </span><span class="ff1">描述如下</span>*</div><div class="t m0 x2 h4 y44 ff2 fs0 fc3 sc0 ls0 ws0">E>C!>+>: - / P /<;!.</div><div class="t m0 x2 h6 y45 ff2 fs0 fc3 sc0 ls0 ws0">%C"!)*+,! -.8!BB<span class="ff1">表<span class="ff4">示<span class="_ _0"> </span></span></span> -<span class="_ _0"> </span><span class="ff1">是输入信号</span> <span class="ff4">并且<span class="ff1">是<span class="_ _0"> </span></span></span><span class="_ _0"> </span><span class="ff1">位<span class="ff4">矢</span>量</span> <span class="ff1">上<span class="ff4">界</span>是<span class="_ _0"> </span></span> <span class="ff1">下<span class="ff4">界</span>是<span class="_ _0"> </span></span>+</div><div class="t m0 x2 h4 y46 ff2 fs0 fc3 sc0 ls0 ws0">%C"!/.</div><div class="t m0 x2 h4 y47 ff2 fs0 fc3 sc0 ls0 ws0">C"%C"!)*+,!P.</div><div class="t m0 x2 h4 y48 ff2 fs0 fc3 sc0 ls0 ws0">C"%C"!/<.</div><div class="t m0 x2 h6 y3c ff2 fs0 fc3 sc0 ls0 ws0">!Q/< PR'0-0/.BB<span class="ff1">一对</span>DQD<span class="ff1">和</span>DRD<span class="_ _1"></span><span class="ff1">表<span class="ff4">示链接</span></span> <span class="ff1">即将<span class="_ _7"> </span></span>/<<span class="_ _0"> </span><span class="ff1">和<span class="_ _0"> </span></span>P<span class="_ _0"> </span><span class="ff1">合<span class="ff4">并</span>成<span class="_ _0"> </span></span><span class="_ _7"> </span><span class="ff1">位<span class="ff4">矢</span>量</span></div><div class="t m0 x2 h4 y49 ff2 fs0 fc3 sc0 ls0 ws0">>E>C</div><div class="t m0 x2 h6 y3e ff2 fs0 fc3 sc0 ls0 ws0">H<span class="ff4">带异<span class="ff1">步</span>清零端<span class="ff1">的<span class="_ _7"> </span></span></span><span class="_ _0"> </span><span class="ff1">触发器的<span class="_ _0"> </span></span><span class="_ _0"> </span><span class="ff1">描述如下</span>*</div><div class="t m0 x2 h4 y4a ff2 fs0 fc3 sc0 ls0 ws0">E>C!>#"I!:> #% #> S S;.</div><div class="t m0 x2 h4 y4b ff2 fs0 fc3 sc0 ls0 ws0">%C"!> #% #>.</div><div class="t m0 x2 h4 y4c ff2 fs0 fc3 sc0 ls0 ws0">C"%C"!S S.</div></div><div class="t m0 x3 h5 y32 ff3 fs1 fc3 sc0 ls0 ws0">3</div></div><div class="pi" data-data='{"ctm":[1.611850,0.000000,0.000000,1.611850,0.000000,0.000000]}'></div></div>
<div id="pf4" class="pf w0 h0" data-page-no="4"><div class="pc pc4 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/626b22d11e41a87e8a848635/bg4.jpg"><div class="c x0 y1 w2 h2"><div class="t m0 x2 h6 y2 ff2 fs0 fc3 sc0 ls0 ws0"><span class="_ _1"></span>!<span class="_ _5"></span>S S.888!<span class="_ _5"></span>BB<span class="_ _8"></span><span class="ff1">关<span class="_ _5"></span><span class="ff4">键<span class="_ _8"></span>字<span class="_ _5"></span></span></span>D<span class="_ _1"></span>D<span class="_ _5"></span><span class="ff1">表<span class="_ _8"></span><span class="ff4">示<span class="_ _3"> </span></span></span>S<span class="_ _3"> </span><span class="ff1">和<span class="_ _3"> </span></span>S<span class="_ _3"> </span><span class="ff1">是<span class="_ _8"></span></span>D"D<span class="_ _5"></span><span class="ff1">类<span class="_ _8"></span>型<span class="_ _5"></span>的<span class="_ _8"></span>信<span class="_ _5"></span>号<span class="_ _8"></span></span>.<span class="_ _3"> </span><span class="ff1">中<span class="_ _5"></span>有<span class="_ _8"></span><span class="ff4">两<span class="_ _5"></span></span>种<span class="_ _8"></span>类<span class="_ _5"></span>型<span class="_ _5"></span>的<span class="_ _8"></span>信<span class="_ _5"></span>号<span class="_ _8"></span></span>*D"D<span class="_ _8"></span><span class="ff1">类<span class="_ _5"></span>型</span></div><div class="t m0 x2 h6 y3 ff1 fs0 fc3 sc0 ls0 ws0">和<span class="ff2">DD<span class="_ _1"></span></span>类型<span class="_ _1"></span><span class="ff2">F<span class="ff4">你<span class="_ _1"></span></span></span>可以<span class="_ _1"></span><span class="ff4">简</span>单<span class="_ _1"></span>地<span class="ff4">把<span class="_ _2"> </span><span class="ff2">"<span class="_ _0"> </span></span></span>类<span class="_ _1"></span>型的<span class="_ _1"></span>信号<span class="_ _1"></span><span class="ff4">想</span>象<span class="_ _1"></span>为<span class="ff4">某<span class="_ _1"></span></span>个<span class="_ _0"> </span><span class="ff2"><span class="_ _2"> </span></span>触发<span class="_ _1"></span>器的<span class="_ _1"></span>输出<span class="_ _1"></span><span class="ff2"> <span class="_ _1"></span></span>而<span class="_ _0"> </span><span class="ff2"><span class="_ _2"> </span></span>类型<span class="_ _1"></span>的的<span class="_ _1"></span>信号<span class="_ _1"></span>是组<span class="_ _1"></span>合逻<span class="_ _1"></span>辑的</div><div class="t m0 x2 h6 y4 ff1 fs0 fc3 sc0 ls0 ws0">输<span class="_ _1"></span>出<span class="_ _5"></span><span class="ff2">F<span class="_ _1"></span></span>二<span class="_ _5"></span>者<span class="_ _1"></span>的<span class="_ _5"></span>最<span class="_ _1"></span><span class="ff4">大<span class="_ _5"></span></span>区<span class="_ _1"></span>别<span class="_ _1"></span>在<span class="_ _5"></span>于<span class="_ _5"></span><span class="ff2">*<span class="_ _5"></span><span class="ff4">你<span class="_ _1"></span></span></span>可<span class="_ _1"></span>以<span class="_ _5"></span>对<span class="_ _3"> </span><span class="ff2">"<span class="_ _2"> </span></span>类<span class="_ _1"></span>型<span class="_ _5"></span>的<span class="_ _1"></span>信<span class="_ _5"></span>号<span class="_ _1"></span>进<span class="_ _1"></span>行<span class="_ _5"></span>定<span class="_ _1"></span>时<span class="_ _5"></span>赋<span class="_ _1"></span>值<span class="_ _8"></span><span class="ff2">:<span class="_ _1"></span></span>用<span class="_ _2"> </span><span class="ff2">"<span class="_ _3"> </span></span>语<span class="_ _1"></span>句<span class="_ _1"></span>在<span class="_ _5"></span><span class="ff4">特<span class="_ _1"></span></span>定<span class="_ _5"></span>时<span class="_ _1"></span><span class="ff4">刻<span class="_ _5"></span></span>的<span class="_ _1"></span>赋<span class="_ _5"></span>值<span class="_ _5"></span><span class="ff2"> <span class="_ _5"></span><span class="ff4">详<span class="_ _1"></span>见<span class="_ _1"></span></span></span>下<span class="_ _5"></span>面</div><div class="t m0 x2 h3 y5 ff2 fs0 fc3 sc0 ls0 ws0"><span class="_ _7"> </span><span class="ff1">语句</span>; <span class="_ _1"></span><span class="ff1">而对于<span class="_ _7"> </span></span><span class="_ _0"> </span><span class="ff1">类型的信号则不可</span>F</div><div class="t m0 x2 h6 y6 ff2 fs0 fc3 sc0 ls0 ws0"><span class="_ _1"></span>!<span class="_ _5"></span>"<span class="_ _1"></span>!<span class="_ _1"></span>:#><span class="_ _1"></span>''+;<span class="_ _1"></span>!<span class="_ _5"></span>BB<span class="_ _5"></span><span class="ff1">表<span class="_ _8"></span><span class="ff4">示<span class="_ _5"></span></span>每<span class="_ _8"></span>当<span class="_ _3"> </span></span>#>'+<span class="_ _3"> </span><span class="ff1">时<span class="_ _8"></span></span> <span class="_ _5"></span><span class="ff1">将<span class="_ _5"></span>要<span class="_ _8"></span>对<span class="_ _3"> </span></span><span class="_ _3"> </span><span class="ff1">触<span class="_ _8"></span>发<span class="_ _5"></span>器<span class="_ _5"></span><span class="ff4">清<span class="_ _8"></span>零<span class="_ _5"></span></span></span> DD<span class="_ _8"></span><span class="ff1">和<span class="_ _5"></span></span>D"D<span class="_ _8"></span><span class="ff4">嵌<span class="_ _5"></span>套<span class="_ _8"></span><span class="ff1">，<span class="_ _5"></span></span></span>D"D<span class="_ _8"></span><span class="ff1">和<span class="_ _5"></span></span>DTD<span class="_ _5"></span><span class="ff1">是</span></div><div class="t m0 x2 h6 y7 ff2 fs0 fc3 sc0 ls0 ws0"><span class="_ _c"> </span><span class="ff1">的<span class="_ _7"> </span><span class="ff4">两<span class="_ _0"> </span></span>个<span class="_ _7"> </span>关<span class="_ _0"> </span><span class="ff4">键<span class="_ _0"> </span>字<span class="_ _7"> </span></span></span> <span class="_ _0"> </span><span class="ff1">表<span class="_ _7"> </span><span class="ff4">示<span class="_ _0"> </span></span>一<span class="_ _0"> </span><span class="ff4">旦<span class="_ _7"> </span></span>有<span class="_ _0"> </span><span class="ff4">某<span class="_ _7"> </span>事<span class="_ _0"> </span></span>发<span class="_ _7"> </span>生<span class="_ _0"> </span>；<span class="_ _7"> </span>则<span class="_ _0"> </span><span class="ff4">执<span class="_ _0"> </span></span>行<span class="_ _7"> </span>下<span class="_ _0"> </span>面<span class="_ _7"> </span>的<span class="_ _0"> </span>语<span class="_ _7"> </span>句<span class="_ _0"> </span>块<span class="_ _0"> </span></span> DD<span class="_ _0"> </span><span class="ff1">有<span class="_ _7"> </span>点<span class="_ _0"> </span>象<span class="_ _c"> </span></span>/<span class="_ _c"> </span><span class="ff1">语<span class="_ _0"> </span><span class="ff4">言<span class="_ _7"> </span></span>中<span class="_ _0"> </span>的<span class="_ _7"> </span></span>D<span class="_ _8"></span>!<span class="_ _8"></span>FFF</div><div class="t m0 x2 h6 y8 ff2 fs0 fc3 sc0 ls0 ws0">"FFFD<span class="ff1">，</span>D"D<span class="ff1">和</span>DTD<span class="ff1">的区别</span>*<span class="_ _1"></span><span class="ff4">请<span class="ff1">参考本模块</span></span>F"<span class="_ _0"> </span><span class="ff1">表<span class="ff4">示</span>本语句块的进程<span class="ff4">停止<span class="_ _5"></span></span></span> <span class="ff4">直<span class="ff1">到</span></span>D#>'+D<span class="ff1">的条件出现<span class="ff4">才继</span>续；<span class="ff4">我理</span></span></div><div class="t m0 x2 h6 y9 ff4 fs0 fc3 sc0 ls0 ws0">解<span class="ff1">在<span class="_ _0"> </span><span class="ff2"><span class="_ _0"> </span></span>中<span class="_ _1"></span><span class="ff2"> </span>每个<span class="_ _1"></span>最外</span>层<span class="_ _1"></span><span class="ff1">语句块<span class="_ _1"></span>都是一<span class="_ _1"></span>个<span class="_ _1"></span><span class="ff2">HHH</span>的进<span class="_ _1"></span>程<span class="ff2">.DTD:<span class="_ _1"></span></span></span>请看<span class="ff1">下<span class="_ _1"></span>个<span class="_ _0"> </span><span class="ff2"><span class="_ _0"> </span></span>语<span class="_ _1"></span>句<span class="ff2">;</span></span>也<span class="_ _1"></span><span class="ff1">表</span>示<span class="ff1">本<span class="_ _1"></span>语句块<span class="_ _1"></span>的进程<span class="_ _1"></span></span>停止<span class="_ _1"></span><span class="ff2"> <span class="_ _1"></span></span>直<span class="ff1">到</span></div><div class="t m0 x2 h6 ya ff1 fs0 fc3 sc0 ls0 ws0">后<span class="_ _5"></span>面<span class="_ _5"></span>定<span class="_ _5"></span>义<span class="_ _8"></span><span class="ff2">D%>!<span class="_ _5"></span>#%D:<span class="_ _5"></span></span>即<span class="_ _5"></span>出<span class="_ _8"></span>现<span class="_ _3"> </span><span class="ff2">#%<span class="_ _3"> </span></span>的<span class="_ _5"></span>上<span class="_ _5"></span><span class="ff4">升<span class="_ _5"></span>沿<span class="_ _8"></span><span class="ff2">;<span class="_ _5"></span></span></span>的<span class="_ _5"></span><span class="ff4">事<span class="_ _5"></span></span>件<span class="_ _5"></span>出<span class="_ _8"></span>现<span class="_ _1"></span><span class="ff4">才<span class="_ _8"></span>继<span class="_ _5"></span></span>续<span class="_ _5"></span><span class="ff2">.<span class="_ _8"></span><span class="ff4">也<span class="_ _5"></span>许<span class="_ _3"> </span></span>"<span class="_ _3"> </span></span>和<span class="_ _5"></span><span class="ff2">T<span class="_ _5"></span></span>可<span class="_ _5"></span>以<span class="_ _5"></span>合<span class="_ _8"></span>二<span class="_ _1"></span>为<span class="_ _8"></span>一<span class="_ _5"></span><span class="ff4">吧<span class="_ _5"></span><span class="ff2"> <span class="_ _8"></span></span>但<span class="_ _1"></span>至<span class="_ _8"></span>少<span class="_ _5"></span></span>到<span class="_ _5"></span>目<span class="_ _5"></span><span class="ff4">前</span></div><div class="t m0 x2 h6 yb ff2 fs0 fc3 sc0 ls0 ws0"><span class="_ _0"> </span><span class="ff1">中<span class="_ _0"> </span></span>"<span class="_ _2"> </span><span class="ff1">表<span class="ff4">示<span class="_ _1"></span></span></span>D<span class="_ _1"></span><span class="ff1">条件<span class="_ _1"></span></span>D T<span class="ff1">表<span class="_ _1"></span><span class="ff4">示<span class="_ _1"></span></span></span>D<span class="_ _1"></span><span class="ff4">事<span class="ff1">件<span class="_ _1"></span></span></span>D.<span class="ff1">具<span class="_ _1"></span>体运<span class="_ _1"></span>用中<span class="_ _5"></span></span> "<span class="_ _0"> </span><span class="ff1">总是<span class="_ _1"></span>用于<span class="_ _1"></span>类似<span class="_ _1"></span></span>D":MMM';D<span class="_ _1"></span><span class="ff4">之<span class="_ _1"></span><span class="ff1">类的<span class="_ _1"></span></span>场<span class="ff1">合<span class="_ _5"></span></span></span> T<span class="ff1">总是<span class="_ _1"></span>用于<span class="_ _1"></span>类</span></div><div class="t m0 x2 h6 yc ff1 fs0 fc3 sc0 ls0 ws0">似<span class="ff2">DT:MMM;D</span>或<span class="ff2">DT:%>B>!MMM;D<span class="ff4">之</span></span>类的<span class="ff4">场</span>合<span class="ff4">整</span>句<span class="ff4">话</span>的意<span class="ff4">思</span>是<span class="ff2">D<span class="_ _1"></span></span>每当<span class="_ _7"> </span><span class="ff2">#><span class="_ _0"> </span></span>等于<span class="_ _0"> </span><span class="ff2">+<span class="_ _0"> </span></span>时<span class="ff2"> </span>则作以下<span class="ff4">事</span>情<span class="ff2">D</span></div><div class="t m0 x2 h6 yd ff2 fs0 fc3 sc0 ls0 ws0">I8888!BBIFFF><span class="_ _0"> </span><span class="ff1">结构的用<span class="ff4">法</span>类似于<span class="_ _0"> </span></span>%#<span class="_ _0"> </span><span class="ff1">语<span class="ff4">言</span></span></div><div class="t m0 x2 h4 y4d ff2 fs0 fc3 sc0 ls0 ws0">888888!S'+.</div><div class="t m0 x2 h4 y4e ff2 fs0 fc3 sc0 ls0 ws0">88888888!S'.</div><div class="t m0 x2 h4 y4f ff2 fs0 fc3 sc0 ls0 ws0">8888888!"!:#>'';.</div><div class="t m0 x2 h4 y50 ff2 fs0 fc3 sc0 ls0 ws0">></div><div class="t m0 x2 h6 y12 ff2 fs0 fc3 sc0 ls0 ws0">!T!:%>!#%;BBDT:%>!#%;D<span class="_ _1"></span><span class="ff1">中有<span class="ff4">两</span>个关<span class="ff4">键字</span></span>*DT!:M;D<span class="ff1">表<span class="ff4">示</span></span>D<span class="ff1">每当<span class="ff4">事</span>件<span class="_ _0"> </span></span>M<span class="_ _0"> </span><span class="ff1">发</span></div><div class="t m0 x2 h6 y13 ff1 fs0 fc3 sc0 ls0 ws0">生<span class="ff2">D D%>!MD<span class="_ _1"></span></span>表<span class="ff4">示<span class="_ _1"></span><span class="ff2">DM<span class="_ _0"> </span></span></span>的<span class="_ _1"></span>上<span class="ff4">升沿<span class="_ _1"></span><span class="ff2"> D>!<span class="_ _1"></span>MD</span></span>表<span class="_ _1"></span><span class="ff4">示<span class="ff2">DM<span class="_ _0"> </span></span></span>的<span class="_ _1"></span>下<span class="ff4">降<span class="_ _1"></span>沿<span class="_ _1"></span><span class="ff2">D</span></span>，<span class="ff4">整<span class="_ _1"></span></span>句<span class="ff4">话</span>的<span class="_ _1"></span>意<span class="ff4">思</span>是<span class="_ _5"></span><span class="ff2">D</span>每当<span class="_ _2"> </span><span class="ff2">#%<span class="_ _0"> </span></span>的上<span class="_ _1"></span><span class="ff4">升沿<span class="_ _1"></span><span class="ff2"> </span></span>则<span class="_ _1"></span>作以下<span class="_ _1"></span><span class="ff4">事</span></div><div class="t m0 x2 h3 y14 ff1 fs0 fc3 sc0 ls0 ws0">情<span class="ff2">D</span></div><div class="t m0 x2 h6 y15 ff2 fs0 fc3 sc0 ls0 ws0">8888888!!:#>;8<span class="_ _1"></span>!BB<span class="ff1">如果<span class="_ _7"> </span></span>#>':<span class="_ _1"></span><span class="ff1">意<span class="ff4">味着清零端</span>无<span class="ff4">效</span></span>;</div><div class="t m0 x2 h4 y51 ff2 fs0 fc3 sc0 ls0 ws0">8888888!I</div><div class="t m0 x2 h4 y52 ff2 fs0 fc3 sc0 ls0 ws0">888888888888<span class="_ _1"></span>8888!S'>.</div><div class="t m0 x2 h6 y18 ff2 fs0 fc3 sc0 ls0 ws0">888888888888<span class="_ _1"></span>8888!S'KS.BBDKD<span class="ff1">表<span class="ff4">示反</span>相</span></div><div class="t m0 x2 h4 y53 ff2 fs0 fc3 sc0 ls0 ws0">8888888!></div><div class="t m0 x2 h4 y33 ff2 fs0 fc3 sc0 ls0 ws0">>E>C</div><div class="t m0 x2 h3 y54 ff2 fs0 fc3 sc0 ls0 ws0">H<span class="ff1">计数器的<span class="_ _7"> </span></span><span class="_ _0"> </span><span class="ff1">描述如下</span>*</div><div class="t m0 x2 h6 y55 ff2 fs0 fc3 sc0 ls0 ws0">E>C!#C": " #% C";!.BB<span class="_ _1"></span><span class="ff1">此计数器</span> <span class="ff1">在<span class="_ _7"> </span></span>#%<span class="_ _0"> </span><span class="ff1">的上<span class="ff4">升沿</span>将输入赋<span class="ff4">给</span>输出</span> <span class="ff1">在<span class="_ _0"> </span></span>#%<span class="_ _0"> </span><span class="ff1">的上<span class="ff4">升沿</span>使输出<span class="ff4">加</span>一</span></div><div class="t m0 x2 h4 y56 ff2 fs0 fc3 sc0 ls0 ws0">%C"!)*+,!.</div><div class="t m0 x2 h4 y57 ff2 fs0 fc3 sc0 ls0 ws0">%C"!" #%.</div><div class="t m0 x2 h4 y58 ff2 fs0 fc3 sc0 ls0 ws0">C"%C"!)*+,!C".</div><div class="t m0 x2 h4 y59 ff2 fs0 fc3 sc0 ls0 ws0">!)*+,!C".</div><div class="t m0 x2 h4 y5a ff2 fs0 fc3 sc0 ls0 ws0">!T!:%>!";</div><div class="t m0 x2 h4 y5b ff2 fs0 fc3 sc0 ls0 ws0">8C"!'!.</div><div class="t m0 x2 h4 y5c ff2 fs0 fc3 sc0 ls0 ws0">!T:%>!#%;</div><div class="t m0 x2 h6 y43 ff2 fs0 fc3 sc0 ls0 ws0">8C"!'!C"0.8!BB<span class="_ _0"> </span><span class="ff4">容许<span class="ff1">一个信号同时出现在等号</span>两端</span> <span class="ff1">只要<span class="ff4">它</span>是<span class="_ _0"> </span></span><span class="_ _0"> </span><span class="ff1">类型的</span></div><div class="t m0 x2 h4 y44 ff2 fs0 fc3 sc0 ls0 ws0">>E>C</div><div class="t m0 x2 h3 y5d ff2 fs0 fc3 sc0 ls0 ws0">H"#<span class="_ _7"> </span><span class="ff1">的描述如下</span>*</div><div class="t m0 x2 h4 y5e ff2 fs0 fc3 sc0 ls0 ws0">!T:#U!!>;</div><div class="t m0 x2 h4 y5f ff2 fs0 fc3 sc0 ls0 ws0">888!!:#U;!S!'!>.</div><div class="t m0 x2 h6 y60 ff2 fs0 fc3 sc0 ls0 ws0">H<span class="ff1">时序<span class="ff4">机</span>的<span class="_ _7"> </span></span><span class="_ _0"> </span><span class="ff1">描述如下</span>*</div><div class="t m0 x2 h6 y61 ff2 fs0 fc3 sc0 ls0 ws0">!T:%>!/7V;8!BB<span class="_ _0"> </span><span class="ff1">是下一个状态</span> W<span class="_ _0"> </span><span class="ff1">是当<span class="ff4">前</span>状态</span>  <span class="_ _0"> </span><span class="ff1">是输入</span>  I<span class="_ _0"> </span><span class="ff1">是输出</span></div><div class="t m0 x2 h4 y62 ff2 fs0 fc3 sc0 ls0 ws0">W'.</div><div class="t m0 x2 h3 y63 ff2 fs0 fc3 sc0 ls0 ws0">!T:W!!"#;!I!BB<span class="ff1">当<span class="_ _0"> </span></span>W<span class="_ _0"> </span><span class="ff1">变化或输入<span class="_ _0"> </span></span> <span class="_ _0"> </span><span class="ff1">变化时<span class="_ _7"> </span></span><span class="_ _0"> </span><span class="ff1">要相应变化</span></div><div class="t m0 x2 h4 y64 ff2 fs0 fc3 sc0 ls0 ws0">!'!W.!BB"</div></div><div class="t m0 x3 h5 y32 ff3 fs1 fc3 sc0 ls0 ws0">4</div></div><div class="pi" data-data='{"ctm":[1.611850,0.000000,0.000000,1.611850,0.000000,0.000000]}'></div></div>
<div id="pf5" class="pf w0 h0" data-page-no="5"><div class="pc pc5 w0 h0"><img class="bi x0 y0 w1 h1" alt="" src="https://static.pudn.com/prod/directory_preview_static/626b22d11e41a87e8a848635/bg5.jpg"><div class="c x0 y1 w2 h2"><div class="t m0 x2 h4 y65 ff2 fs0 fc3 sc0 ls0 ws0">!'!+.</div><div class="t m0 x2 h4 y66 ff2 fs0 fc3 sc0 ls0 ws0">I!'!+.</div><div class="t m0 x2 h4 y67 ff2 fs0 fc3 sc0 ls0 ws0">FFFFFF</div><div class="t m0 x2 h4 y68 ff2 fs0 fc3 sc0 ls0 ws0">#:W;</div><div class="t m0 x2 h4 y69 ff2 fs0 fc3 sc0 ls0 ws0">8!S*I</div><div class="t m0 x2 h4 y6a ff2 fs0 fc3 sc0 ls0 ws0">88!S!#".</div><div class="t m0 x2 h4 y6b ff2 fs0 fc3 sc0 ls0 ws0">88!:;'>.</div><div class="t m0 x2 h4 y6c ff2 fs0 fc3 sc0 ls0 ws0">88!:;'>.</div><div class="t m0 x2 h4 y6d ff2 fs0 fc3 sc0 ls0 ws0">88!!'>.</div><div class="t m0 x2 h4 y6e ff2 fs0 fc3 sc0 ls0 ws0">88!!'!.!BB"!</div><div class="t m0 x2 h4 y6f ff2 fs0 fc3 sc0 ls0 ws0">88!></div><div class="t m0 x2 h4 y70 ff2 fs0 fc3 sc0 ls0 ws0">8!S*I</div><div class="t m0 x2 h4 y4d ff2 fs0 fc3 sc0 ls0 ws0">88!I!'!.</div><div class="t m0 x2 h4 y4e ff2 fs0 fc3 sc0 ls0 ws0">88!FFFFFF</div><div class="t m0 x2 h4 y4f ff2 fs0 fc3 sc0 ls0 ws0">88!></div><div class="t m0 x2 h4 y50 ff2 fs0 fc3 sc0 ls0 ws0">8!>C"*I</div><div class="t m0 x2 h4 y71 ff2 fs0 fc3 sc0 ls0 ws0">88!!'!+.</div><div class="t m0 x2 h4 y42 ff2 fs0 fc3 sc0 ls0 ws0">88!I!'!+.</div><div class="t m0 x2 h4 y72 ff2 fs0 fc3 sc0 ls0 ws0">88!FFFFFF</div><div class="t m0 x2 h4 y73 ff2 fs0 fc3 sc0 ls0 ws0">></div><div class="t m0 x2 h4 y51 ff2 fs0 fc3 sc0 ls0 ws0">></div><div class="t m0 x2 h4 y52 ff2 fs0 fc3 sc0 ls0 ws0">&&&""&&&</div><div class="t m0 x2 h4 y74 ff2 fs0 fc3 sc0 ls0 ws0">"!*</div><div class="t m0 x2 h4 y53 ff2 fs0 fc3 sc0 ls0 ws0">8!4!!!#C"E!M% "!" !C>!I!SC!"!W.</div><div class="t m0 x2 h4 y33 ff2 fs0 fc3 sc0 ls0 ws0">"!*</div><div class="t m0 x2 h4 y75 ff2 fs0 fc3 sc0 ls0 ws0">8!!"!""!E# !!!SC!"!!"!""!S </div><div class="t m0 x2 h4 y76 ff2 fs0 fc3 sc0 ls0 ws0">8!"!"" !!SC!"!+.</div><div class="t m0 x2 h3 y1d ff2 fs0 fc3 sc0 ls0 ws0">H!=<span class="_ _7"> </span><span class="ff1">的<span class="_ _0"> </span></span><span class="_ _0"> </span><span class="ff1">描述如下</span>*</div><div class="t m0 x2 h6 y1e ff2 fs0 fc3 sc0 ls0 ws0">E>C!E:>  >C" C" > ;.BB<span class="_ _5"></span><span class="ff1">这是一个<span class="_ _1"></span><span class="ff4">双口<span class="_ _2"> </span></span></span>= <span class="_ _1"></span><span class="ff1">分别有<span class="_ _1"></span></span>*<span class="ff1">输<span class="_ _1"></span>入<span class="ff4">端<span class="_ _1"></span></span></span>*<span class="ff1">输<span class="_ _1"></span>入地<span class="ff4">址<span class="_ _2"> </span></span></span>.<span class="_ _1"></span><span class="ff1">输入数<span class="_ _1"></span>据<span class="_ _0"> </span></span>>.<span class="_ _1"></span><span class="ff1">上<span class="ff4">升沿<span class="_ _1"></span></span>有</span></div><div class="t m0 x2 h6 y1f ff4 fs0 fc3 sc0 ls0 ws0">效<span class="ff1">的</span>写<span class="ff1">信号<span class="_ _7"> </span><span class="ff2">.B</span>输出</span>端<span class="ff2">*<span class="ff1">输出地</span></span>址<span class="_ _0"> </span><span class="ff2">C".<span class="ff1">输出数据<span class="_ _0"> </span></span>>C".<span class="ff1">高电</span></span>平<span class="ff1">有</span>效<span class="ff1">的读信号<span class="_ _0"> </span><span class="ff2">>.</span></span></div><div class="t m0 x2 h4 y77 ff2 fs0 fc3 sc0 ls0 ws0">8!C"!)*+,!>.</div><div class="t m0 x2 h4 y21 ff2 fs0 fc3 sc0 ls0 ws0">8!%C"!)*+,! C".</div><div class="t m0 x2 h4 y22 ff2 fs0 fc3 sc0 ls0 ws0">8!%C"!> .</div><div class="t m0 x2 h4 y23 ff2 fs0 fc3 sc0 ls0 ws0">8!C"%C"!)*+,!>C".</div><div class="t m0 x2 h6 y24 ff2 fs0 fc3 sc0 ls0 ws0">8!!)*+,!EE!)+*,.88!<span class="_ _1"></span>BB<span class="ff4">请<span class="ff1">注意这是存</span>储阵<span class="ff1">列的描述方</span>法</span> <span class="ff1">描述了一个共有<span class="_ _7"> </span></span></div><div class="t m0 x2 h6 y25 ff2 fs0 fc3 sc0 ls0 ws0"><span class="_ _7"> </span><span class="ff1">个<span class="ff4">字</span>的存<span class="ff4">储阵</span>列</span> <span class="ff1">每个<span class="ff4">字</span>是<span class="_ _0"> </span></span><span class="_ _0"> </span><span class="ff1">位</span></div><div class="t m0 x2 h6 y26 ff2 fs0 fc3 sc0 ls0 ws0">8!!>C"!'!>!X!EE)C",!*!YIJ.!BBDD<span class="_ _1"></span><span class="ff1">关<span class="ff4">键字</span>表<span class="ff4">示并</span>行赋值语句的</span></div><div class="t m0 x2 h6 y27 ff4 fs0 fc3 sc0 ls0 ws0">开<span class="ff1">始<span class="ff2">DXD</span>运<span class="_ _1"></span>算符的作用和<span class="_ _1"></span>在<span class="_ _2"> </span><span class="ff2">/<span class="_ _0"> </span></span>语</span>言<span class="ff1">中一<span class="_ _1"></span>样<span class="ff2">DYI<span class="_ _1"></span>JD</span>是一个常<span class="_ _1"></span>量<span class="ff2"> <span class="_ _1"></span></span>表</span>示<span class="ff1">一个</span>字<span class="_ _1"></span>节<span class="ff1">的高阻态<span class="_ _5"></span><span class="ff2"> </span></span>其<span class="ff1">中<span class="_ _0"> </span><span class="ff2"><span class="_ _0"> </span></span>表</span>示<span class="_ _1"></span>长度<span class="ff1">是<span class="_ _2"> </span><span class="ff2">I" DYD</span>是</span>固<span class="_ _1"></span><span class="ff1">定</span></div><div class="t m0 x2 h6 y28 ff1 fs0 fc3 sc0 ls0 ws0">分<span class="ff4">割<span class="_ _1"></span></span>符<span class="_ _1"></span><span class="ff2"> DID<span class="_ _1"></span></span>表<span class="ff4">示<span class="_ _1"></span></span>后<span class="_ _1"></span>面的<span class="_ _1"></span>数<span class="_ _1"></span>据是<span class="_ _1"></span>以<span class="_ _1"></span>比<span class="_ _1"></span><span class="ff4">特形<span class="_ _1"></span></span>式<span class="_ _1"></span><span class="ff4">给<span class="_ _1"></span></span>出的<span class="_ _1"></span><span class="ff2"> DJD<span class="_ _1"></span></span>表<span class="ff4">示<span class="_ _1"></span></span>高<span class="_ _1"></span>阻<span class="_ _1"></span><span class="ff2">.<span class="ff4">举<span class="_ _1"></span>例<span class="_ _1"></span></span>*Y<span class="_ _0"> </span></span>表<span class="_ _1"></span><span class="ff4">示<span class="_ _1"></span>长<span class="_ _0"> </span><span class="ff2">I"<span class="_ _2"> </span></span></span>的数<span class="_ _1"></span><span class="ff2">D++D<span class="_ _1"></span></span>。<span class="_ _1"></span>类似<span class="_ _1"></span>的<span class="_ _1"></span>还可<span class="_ _1"></span><span class="ff4">举<span class="_ _1"></span></span>出</div><div class="t m0 x2 h3 y29 ff2 fs0 fc3 sc0 ls0 ws0">YI+ Y<span class="_ _7"> </span><span class="ff1">等等</span></div><div class="t m0 x2 h4 y78 ff2 fs0 fc3 sc0 ls0 ws0">8!!T:%>!;</div><div class="t m0 x2 h4 y79 ff2 fs0 fc3 sc0 ls0 ws0">EE),!'!>.</div><div class="t m0 x2 h4 y7a ff2 fs0 fc3 sc0 ls0 ws0">>E>C</div><div class="t m0 x2 h3 y2d ff2 fs0 fc3 sc0 ls0 ws0">H<span class="ff1">模块引用</span></div><div class="t m0 x2 h6 y2e ff4 fs0 fc3 sc0 ls0 ws0">假<span class="ff1">设在</span>前<span class="ff1">面<span class="ff2">:</span>可以是别的模块<span class="ff2">;</span>定义了<span class="_ _7"> </span><span class="ff2">E>C!E:>  >C" C" > ; <span class="_ _1"></span></span>则引用此</span></div><div class="t m0 x2 h6 y2f ff1 fs0 fc3 sc0 ls0 ws0">模块时只需<span class="ff4">写</span></div><div class="t m0 x2 h4 y7b ff2 fs0 fc3 sc0 ls0 ws0">E!EE:>GGE% GGE% >C"GGE% C"GGE% >GGE% GGE%;</div><div class="t m0 x2 h4 y7c ff2 fs0 fc3 sc0 ls0 ws0">.</div></div><div class="t m0 x3 h5 y32 ff3 fs1 fc3 sc0 ls0 ws0">5</div></div><div class="pi" data-data='{"ctm":[1.611850,0.000000,0.000000,1.611850,0.000000,0.000000]}'></div></div>
