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<li class="toctree-l1 current"><a class="current reference internal" href="#">usbd_cdc_acm</a></li>
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<li class="toctree-l1"><a class="reference internal" href="../usbip/ohci.html">OHCI</a></li>
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<section id="usbd-cdc-acm">
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<h1>usbd_cdc_acm<a class="headerlink" href="#usbd-cdc-acm" title="Link to this heading"></a></h1>
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<p>本 demo 主要用于演示 cdc acm 功能，包含收发测试，DTR 控制，ZLP 测试，性能测试。</p>
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<ul class="simple">
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<li><p>开辟读写 buffer，用于收发数据，并且buffer需要用 nocache 修饰，这里我们读写都是用 2048字节，是为了后面的 ZLP 测试和性能测试使用。</p></li>
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</ul>
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<div class="highlight-C notranslate"><div class="highlight"><pre><span></span><span class="n">USB_NOCACHE_RAM_SECTION</span><span class="w"> </span><span class="n">USB_MEM_ALIGNX</span><span class="w"> </span><span class="kt">uint8_t</span><span class="w"> </span><span class="n">read_buffer</span><span class="p">[</span><span class="mi">2048</span><span class="p">];</span><span class="w"> </span><span class="cm">/* 2048 is only for test speed , please use CDC_MAX_MPS for common*/</span>
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<span class="n">USB_NOCACHE_RAM_SECTION</span><span class="w"> </span><span class="n">USB_MEM_ALIGNX</span><span class="w"> </span><span class="kt">uint8_t</span><span class="w"> </span><span class="n">write_buffer</span><span class="p">[</span><span class="mi">2048</span><span class="p">];</span>
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</pre></div>
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</div>
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<ul class="simple">
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<li><p>在协议栈事件回调中，我们需要在枚举完成后启动第一次传输，并清除相关 flag，可以在 reset 事件中清除，也可以在 configured 事件中清除。</p></li>
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</ul>
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<div class="highlight-C notranslate"><div class="highlight"><pre><span></span><span class="k">static</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">usbd_event_handler</span><span class="p">(</span><span class="kt">uint8_t</span><span class="w"> </span><span class="n">busid</span><span class="p">,</span><span class="w"> </span><span class="kt">uint8_t</span><span class="w"> </span><span class="n">event</span><span class="p">)</span>
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<span class="p">{</span>
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<span class="w"> </span><span class="k">switch</span><span class="w"> </span><span class="p">(</span><span class="n">event</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
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<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="no">USBD_EVENT_RESET</span><span class="p">:</span>
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<span class="w"> </span><span class="k">break</span><span class="p">;</span>
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<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="no">USBD_EVENT_CONNECTED</span><span class="p">:</span>
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<span class="w"> </span><span class="k">break</span><span class="p">;</span>
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<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="no">USBD_EVENT_DISCONNECTED</span><span class="p">:</span>
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<span class="w"> </span><span class="k">break</span><span class="p">;</span>
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<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="no">USBD_EVENT_RESUME</span><span class="p">:</span>
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<span class="w"> </span><span class="k">break</span><span class="p">;</span>
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<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="no">USBD_EVENT_SUSPEND</span><span class="p">:</span>
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<span class="w"> </span><span class="k">break</span><span class="p">;</span>
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<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="no">USBD_EVENT_CONFIGURED</span><span class="p">:</span>
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<span class="w"> </span><span class="n">ep_tx_busy_flag</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">false</span><span class="p">;</span>
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<span class="w"> </span><span class="cm">/* setup first out ep read transfer */</span>
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<span class="w"> </span><span class="n">usbd_ep_start_read</span><span class="p">(</span><span class="n">busid</span><span class="p">,</span><span class="w"> </span><span class="n">CDC_OUT_EP</span><span class="p">,</span><span class="w"> </span><span class="n">read_buffer</span><span class="p">,</span><span class="w"> </span><span class="mi">2048</span><span class="p">);</span>
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<span class="w"> </span><span class="k">break</span><span class="p">;</span>
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<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="no">USBD_EVENT_SET_REMOTE_WAKEUP</span><span class="p">:</span>
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<span class="w"> </span><span class="k">break</span><span class="p">;</span>
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<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="no">USBD_EVENT_CLR_REMOTE_WAKEUP</span><span class="p">:</span>
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<span class="w"> </span><span class="k">break</span><span class="p">;</span>
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<span class="w"> </span><span class="k">default</span><span class="o">:</span>
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<span class="w"> </span><span class="k">break</span><span class="p">;</span>
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<span class="w"> </span><span class="p">}</span>
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<span class="p">}</span>
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</pre></div>
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</div>
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<ul class="simple">
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<li><p>在接收完成中断中继续发起接收；在发送完成中断中判断是否需要发送 ZLP。</p></li>
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</ul>
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<div class="highlight-C notranslate"><div class="highlight"><pre><span></span><span class="kt">void</span><span class="w"> </span><span class="nf">usbd_cdc_acm_bulk_out</span><span class="p">(</span><span class="kt">uint8_t</span><span class="w"> </span><span class="n">busid</span><span class="p">,</span><span class="w"> </span><span class="kt">uint8_t</span><span class="w"> </span><span class="n">ep</span><span class="p">,</span><span class="w"> </span><span class="kt">uint32_t</span><span class="w"> </span><span class="n">nbytes</span><span class="p">)</span>
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<span class="p">{</span>
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<span class="w"> </span><span class="n">USB_LOG_RAW</span><span class="p">(</span><span class="s">"actual out len:%d</span><span class="se">\r\n</span><span class="s">"</span><span class="p">,</span><span class="w"> </span><span class="n">nbytes</span><span class="p">);</span>
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<span class="w"> </span><span class="c1">// for (int i = 0; i < 100; i++) {</span>
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<span class="w"> </span><span class="c1">// printf("%02x ", read_buffer[i]);</span>
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<span class="w"> </span><span class="c1">// }</span>
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<span class="w"> </span><span class="c1">// printf("\r\n");</span>
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<span class="w"> </span><span class="cm">/* setup next out ep read transfer */</span>
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<span class="w"> </span><span class="n">usbd_ep_start_read</span><span class="p">(</span><span class="n">busid</span><span class="p">,</span><span class="w"> </span><span class="n">CDC_OUT_EP</span><span class="p">,</span><span class="w"> </span><span class="n">read_buffer</span><span class="p">,</span><span class="w"> </span><span class="mi">2048</span><span class="p">);</span>
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<span class="p">}</span>
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<span class="kt">void</span><span class="w"> </span><span class="nf">usbd_cdc_acm_bulk_in</span><span class="p">(</span><span class="kt">uint8_t</span><span class="w"> </span><span class="n">busid</span><span class="p">,</span><span class="w"> </span><span class="kt">uint8_t</span><span class="w"> </span><span class="n">ep</span><span class="p">,</span><span class="w"> </span><span class="kt">uint32_t</span><span class="w"> </span><span class="n">nbytes</span><span class="p">)</span>
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<span class="p">{</span>
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<span class="w"> </span><span class="n">USB_LOG_RAW</span><span class="p">(</span><span class="s">"actual in len:%d</span><span class="se">\r\n</span><span class="s">"</span><span class="p">,</span><span class="w"> </span><span class="n">nbytes</span><span class="p">);</span>
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<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">((</span><span class="n">nbytes</span><span class="w"> </span><span class="o">%</span><span class="w"> </span><span class="n">usbd_get_ep_mps</span><span class="p">(</span><span class="n">busid</span><span class="p">,</span><span class="w"> </span><span class="n">ep</span><span class="p">))</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="o">&&</span><span class="w"> </span><span class="n">nbytes</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
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<span class="w"> </span><span class="cm">/* send zlp */</span>
|
||
<span class="w"> </span><span class="n">usbd_ep_start_write</span><span class="p">(</span><span class="n">busid</span><span class="p">,</span><span class="w"> </span><span class="n">CDC_IN_EP</span><span class="p">,</span><span class="w"> </span><span class="nb">NULL</span><span class="p">,</span><span class="w"> </span><span class="mi">0</span><span class="p">);</span>
|
||
<span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
|
||
<span class="w"> </span><span class="n">ep_tx_busy_flag</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">false</span><span class="p">;</span>
|
||
<span class="w"> </span><span class="p">}</span>
|
||
<span class="p">}</span>
|
||
</pre></div>
|
||
</div>
|
||
<ul class="simple">
|
||
<li><p>以下是为了测试 DTR 功能并控制 USB 发送，DTR 和 RTS 只用于搭配 UART 使用，如果是纯 USB，没什么用，这里仅做测试。DTR 开关使用任意串口上位机并勾选 DTR。</p></li>
|
||
</ul>
|
||
<div class="highlight-C notranslate"><div class="highlight"><pre><span></span><span class="kt">void</span><span class="w"> </span><span class="nf">usbd_cdc_acm_set_dtr</span><span class="p">(</span><span class="kt">uint8_t</span><span class="w"> </span><span class="n">busid</span><span class="p">,</span><span class="w"> </span><span class="kt">uint8_t</span><span class="w"> </span><span class="n">intf</span><span class="p">,</span><span class="w"> </span><span class="kt">bool</span><span class="w"> </span><span class="n">dtr</span><span class="p">)</span>
|
||
<span class="p">{</span>
|
||
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">dtr</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
|
||
<span class="w"> </span><span class="n">dtr_enable</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
|
||
<span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
|
||
<span class="w"> </span><span class="n">dtr_enable</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
|
||
<span class="w"> </span><span class="p">}</span>
|
||
<span class="p">}</span>
|
||
</pre></div>
|
||
</div>
|
||
<ul class="simple">
|
||
<li><p>在主函数中一直调用发送即可</p></li>
|
||
</ul>
|
||
<div class="highlight-C notranslate"><div class="highlight"><pre><span></span><span class="kt">void</span><span class="w"> </span><span class="nf">cdc_acm_data_send_with_dtr_test</span><span class="p">(</span><span class="kt">uint8_t</span><span class="w"> </span><span class="n">busid</span><span class="p">)</span>
|
||
<span class="p">{</span>
|
||
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">dtr_enable</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
|
||
<span class="w"> </span><span class="n">ep_tx_busy_flag</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">true</span><span class="p">;</span>
|
||
<span class="w"> </span><span class="n">usbd_ep_start_write</span><span class="p">(</span><span class="n">busid</span><span class="p">,</span><span class="w"> </span><span class="n">CDC_IN_EP</span><span class="p">,</span><span class="w"> </span><span class="n">write_buffer</span><span class="p">,</span><span class="w"> </span><span class="mi">2048</span><span class="p">);</span>
|
||
<span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="n">ep_tx_busy_flag</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
|
||
<span class="w"> </span><span class="p">}</span>
|
||
<span class="w"> </span><span class="p">}</span>
|
||
<span class="p">}</span>
|
||
</pre></div>
|
||
</div>
|
||
<ul class="simple">
|
||
<li><p>上述我们需要注意，长度设置为 2048 是为了测试 ZLP 功能，通常实际使用时，接收长度应该使用 CDC_MAX_MPS 。具体原因参考 <a class="reference internal" href="../usb/usb_ext.html#usb-ext"><span class="std std-ref">USB 知识点拓展</span></a></p></li>
|
||
<li><p>如果需要做性能测试，使用 tools/test_srcipts/test_cdc_speed.py 进行测试,并在测试之前删除 <cite>usbd_cdc_acm_bulk_out</cite> 和 <cite>usbd_cdc_acm_bulk_in</cite> 中的打印，否则会影响测试结果。</p></li>
|
||
</ul>
|
||
<p>此外，对于 CDC ACM 搭配 OS 的情况，通常我们 read 使用异步并将数据存储到 ringbuffer 中，write 使用同步搭配 sem 使用。</p>
|
||
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