我用的是探索者STM32F407开发板的USB读卡器程序，想请教一下代码中有没有什么命令可以断开USB和电脑的连接？下面这些函数有没有断开功能？
static uint8_t USBD_SetupStage(USB_OTG_CORE_HANDLE *pdev);
static uint8_t USBD_DataOutStage(USB_OTG_CORE_HANDLE *pdev , uint8_t epnum);
static uint8_t USBD_DataInStage(USB_OTG_CORE_HANDLE *pdev , uint8_t epnum);
static uint8_t USBD_SOF(USB_OTG_CORE_HANDLE  *pdev);
static uint8_t USBD_Reset(USB_OTG_CORE_HANDLE  *pdev);
static uint8_t USBD_Suspend(USB_OTG_CORE_HANDLE  *pdev);
static uint8_t USBD_Resume(USB_OTG_CORE_HANDLE  *pdev);
#ifdef VBUS_SENSING_ENABLED
static uint8_t USBD_DevConnected(USB_OTG_CORE_HANDLE  *pdev);
static uint8_t USBD_DevDisconnected(USB_OTG_CORE_HANDLE  *pdev);
#endif
static uint8_t USBD_IsoINIncomplete(USB_OTG_CORE_HANDLE  *pdev);
static uint8_t USBD_IsoOUTIncomplete(USB_OTG_CORE_HANDLE  *pdev);
static uint8_t  USBD_RunTestMode (USB_OTG_CORE_HANDLE  *pdev) ;



USBD_Status USBD_DeInit(USB_OTG_CORE_HANDLE *pdev);

USBD_Status USBD_ClrCfg(USB_OTG_CORE_HANDLE  *pdev, uint8_t cfgidx);

USBD_Status USBD_SetCfg(USB_OTG_CORE_HANDLE  *pdev, uint8_t cfgidx);