usb设备模式 主机模式

        enum USB_Modes_t {
            USB_MODE_None   = 0,            /**< Indicates that the controller is currently not initialized in any specific USB mode. */
            USB_MODE_Device = 1,            /**< Indicates that the controller is currently initialized in USB Device mode. */
            USB_MODE_Host   = 2,            /**< Indicates that the controller is currently initialized in USB Host mode. */
            USB_MODE_UID    = 3,            /**< Indicates that the controller should determine the USB mode from the UID pin of the
                                             *   USB connector.
                                             */
        };