Question

我正在开发一个使用STM32L442KC的项目，我无法检测USB设备模式何时断开（拔下USB线）。

如何检测USB断线？有中断吗？或者我需要检查一些标志？

更新

以下是STM32CubeMX生成的IRQ处理程序。它没有 HAL_PCD_DisconnectCallback 回调，并且在拔下电缆时未调用 HAL_PCD_SuspendCallback 。

void HAL_PCD_IRQHandler(PCD_HandleTypeDef *hpcd)
{
  uint32_t wInterrupt_Mask = 0;

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_CTR))
  {
    /* servicing of the endpoint correct transfer interrupt */
    /* clear of the CTR flag into the sub */
    PCD_EP_ISR_Handler(hpcd);
  }

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_RESET))
  {
    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_RESET);
    HAL_PCD_ResetCallback(hpcd);
    HAL_PCD_SetAddress(hpcd, 0);
  }

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_PMAOVR))
  {
    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_PMAOVR);    
  }

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_ERR))
  {
    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_ERR); 
  }

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_WKUP))
  {

    hpcd->Instance->CNTR &= ~(USB_CNTR_LPMODE);

    /*set wInterrupt_Mask global variable*/
    wInterrupt_Mask = USB_CNTR_CTRM  | USB_CNTR_WKUPM | USB_CNTR_SUSPM | USB_CNTR_ERRM \
      | USB_CNTR_SOFM | USB_CNTR_ESOFM | USB_CNTR_RESETM;

    /*Set interrupt mask*/
    hpcd->Instance->CNTR = wInterrupt_Mask;

    /* enable L1REQ interrupt */ 
    if (hpcd->Init.lpm_enable ==1)
    {
      wInterrupt_Mask |= USB_CNTR_L1REQM;

      /* Enable LPM support and enable ACK answer to LPM request*/
      USB_TypeDef *USBx = hpcd->Instance;
      hpcd->lpm_active = ENABLE;
      hpcd->LPM_State = LPM_L0;

      USBx->LPMCSR |= (USB_LPMCSR_LMPEN);
      USBx->LPMCSR |= (USB_LPMCSR_LPMACK);
    } 

    if(hpcd->LPM_State == LPM_L1)
    {
      hpcd->LPM_State = LPM_L0;
      HAL_PCDEx_LPM_Callback(hpcd, PCD_LPM_L0_ACTIVE);
    }

    HAL_PCD_ResumeCallback(hpcd);

    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_WKUP);     
  }

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_SUSP))
  {    
    /* clear of the ISTR bit must be done after setting of CNTR_FSUSP */
    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_SUSP);  

    /* Force low-power mode in the macrocell */
    hpcd->Instance->CNTR |= USB_CNTR_FSUSP;
    hpcd->Instance->CNTR |= USB_CNTR_LPMODE;

    if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_WKUP) == 0)
    {
      HAL_PCD_SuspendCallback(hpcd);
    }
  }

  /* Handle LPM Interrupt */ 
  if(__HAL_PCD_GET_FLAG(hpcd, USB_ISTR_L1REQ))
  {
    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_L1REQ);      
    if( hpcd->LPM_State == LPM_L0)
    {   
      /* Force suspend and low-power mode before going to L1 state*/
      hpcd->Instance->CNTR |= USB_CNTR_LPMODE;
      hpcd->Instance->CNTR |= USB_CNTR_FSUSP;

      hpcd->LPM_State = LPM_L1;
      hpcd->BESL = (hpcd->Instance->LPMCSR & USB_LPMCSR_BESL) >>2 ;  
      HAL_PCDEx_LPM_Callback(hpcd, PCD_LPM_L1_ACTIVE);
    }
    else
    {
      HAL_PCD_SuspendCallback(hpcd);
    }
  }

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_SOF))
  {
    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_SOF); 
    HAL_PCD_SOFCallback(hpcd);
  }

  if (__HAL_PCD_GET_FLAG (hpcd, USB_ISTR_ESOF))
  {
    /* clear ESOF flag in ISTR */
    __HAL_PCD_CLEAR_FLAG(hpcd, USB_ISTR_ESOF); 
  }
}

Answer 1

在STM32 F7中，您可以在文件usbd_conf.c中检测函数<script src="//unpkg.com/prismjs/components/prism-ruby.js"></script>中的断开连接。我希望它在L4中会是一样的。

检测STM32L442 USB断开连接

1 个答案: