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17.12.4 例子</div>
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The following are examples of multiple-clock specifications: </p><div class="Element170">
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<div class="Element13"><div class="Element12" id="code00732"><pre class="Element12">sequence s1;
@(posedge clk1) a ##1 b; // single clock sequence
endsequence
sequence s2;
@(posedge clk2) c ##1 d; // single clock sequence
endsequence</pre></div></div>
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1) multiple-clock sequence </p><div class="Element170">
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<div class="Element13"><div class="Element12" id="code00733"><pre class="Element12">sequence mult_s;
@(posedge clk) a ##1 @(posedge clk1) s1 ##1 @(posedge clk2) s2;
endsequence</pre></div></div>
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2) property with a multiple-clock sequence </p><div class="Element170">
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<div class="Element13"><div class="Element12" id="code00734"><pre class="Element12">property mult_p1;
@(posedge clk) a ##1 @(posedge clk1) s1 ##1 @(posedge clk2) s2;
endproperty</pre></div></div>
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3) property with a named multiple-clock sequence </p><div class="Element170">
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<div class="Element13"><div class="Element12" id="code00735"><pre class="Element12">property mult_p2;
mult_s;
endproperty</pre></div></div>
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4) property with multiple-clock implication </p><div class="Element170">
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<div class="Element13"><div class="Element12" id="code00736"><pre class="Element12">property mult_p3;
@(posedge clk) a ##1 @(posedge clk1) s1 |=> @(posedge clk2) s2;
endproperty</pre></div></div>
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5) property with named sequences at different clocks. In this case, if s1 contains a clock, then it must be identical to (posedge clk1). Similarly, if s2 contains a clock, it must be identical to (posedge clk2). </p><div class="Element170">
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<div class="Element13"><div class="Element12" id="code00737"><pre class="Element12">property mult_p5
@(posedge clk1) s1 |=> @(posedge clk2) s2;
endproperty</pre></div></div>
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6) property with implication, where antecedent and consequent are named multi-clocked sequences </p><div class="Element170">
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<div class="Element13"><div class="Element12" id="code00738"><pre class="Element12">property mult_p6;
mult_s |=> mult_s;
endproperty</pre></div></div>
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7) property using clock flow and overlapped implication: </p><div class="Element170">
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<div class="Element13"><div class="Element12" id="code00739"><pre class="Element12">property mult_p7;
@(posedge clk) a ##1 b |-> c ##1 @(posedge clk1) d;
endproperty</pre></div></div>
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Here, a, b, and c are clocked at posedge clk. </p>
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8) property using clock flow and if...else: </p><div class="Element170">
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<div class="Element13"><div class="Element12" id="code00740"><pre class="Element12">property mult_p8;
@(posedge clk) a ##1 b |->
if (c)
(1 |=> @(posedge clk1) d)
else
e ##1 @(posedge clk2) f ;
endproperty</pre></div></div>
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Here, a, b, c, and e are clocked at posedge clk.</p></div>
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