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<h2>
<a name="1102979"> </a><font color="#003366" face="Verdana, Arial, Helvetica, sans-serif">stop</font>
</h2><hr>
<p>
<a name="1102981"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">stop process</font>
</p>
<h5>
<a name="1105345"> </a><i><font color="#003366" face="Verdana, Arial, Helvetica, sans-serif">Code</font></i>
</h5>
<p>
<a name="1102982"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">23 F4</font>
</p>
<h5>
<a name="1106131"> </a><i><font color="#003366" face="Verdana, Arial, Helvetica, sans-serif">Description</font></i>
</h5>
<p>
<a name="1102983"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">Terminate the current process, saving the current <span class=Signal>Iptr</span> and <span class=Signal>Wptr</span> for later use, and start the next process from the scheduling queue. If the scheduling queue is empty then the CPU will become idle. This instruction is implemented in two stages to protect interrupt latency. The first stage deschedules the current process and sets the <span class=Signal>start_next_task</span> status bit. The second stage clears the <span class=Signal>start_next_task</span> status bit and starts the next process. An interrupt may occur between the two stages.</font>
</p>
<p>
<a name="1137212"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">The <span class=Signal>Tdesc</span> register should always be initialised, even if a <strong>stop</strong> trap is installed. When a <strong>stop</strong> trap is taken, the process descriptor block (that is, the data structure pointed to by <span class=Signal>Tdesc</span>) becomes undefined (may be overwritten)</font>
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<p>
<a name="1135696"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif"><em>Note: Between the <strong>stop</strong> instruction being executed and the next instruction starting, the ST20-C1 may have become idle for a period. If it does not pass through the idle state (that is, another task was available on the scheduling queue when <strong>stop</strong> was executed), then these <span class=Signal>status</span> register bits are not affected by the <strong>stop</strong> instruction:</em></font>
</p>
<ul>
<p> <font size=2 face="Verdana, Arial, Helvetica, sans-serif"><li ><a name="1135697"> </a><span class=Signal>interrupt_mode</span>, </font></p>
<p> <font size=2 face="Verdana, Arial, Helvetica, sans-serif"><li ><a name="1135698"> </a><span class=Signal>trap_mode</span>, </font></p>
<p> <font size=2 face="Verdana, Arial, Helvetica, sans-serif"><li ><a name="1135699"> </a><span class=Signal>global_interrupt_enable</span>.</font></p>
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<h5>
<a name="1108177"> </a><i><font color="#003366" face="Verdana, Arial, Helvetica, sans-serif">Definition</font></i>
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<p>
<a name="1128468"> </a><font size=2 face="Verdana, Arial, Helvetica, sans-serif">if (<em>stop trap handler installed</em>)<br>⌨️ 快捷键说明
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