#define LOBYTE(x)  ((uint8_t)(x & 0x00FF))
#define HIBYTE(x)  ((uint8_t)((x & 0xFF00) >>8))

#define USBD_VID                                0x0483
#define USBD_PID                                0x5730

#define USB_DEVICE_DESCRIPTOR_TYPE              0x01
#define USB_CONFIGURATION_DESCRIPTOR_TYPE       0x02
#define USB_STRING_DESCRIPTOR_TYPE              0x03
#define USB_INTERFACE_DESCRIPTOR_TYPE           0x04
#define USB_ENDPOINT_DESCRIPTOR_TYPE            0x05
#define USB_SIZ_DEVICE_DESC                     18
#define USB_SIZ_STRING_LANGID                   4

#define USB_OTG_MAX_EP0_SIZE                    64

#define  USBD_IDX_LANGID_STR                    0x00 
#define  USBD_IDX_MFC_STR                       0x01 
#define  USBD_IDX_PRODUCT_STR                   0x02
#define  USBD_IDX_SERIAL_STR                    0x03 
#define  USBD_IDX_CONFIG_STR                    0x04 
#define  USBD_IDX_INTERFACE_STR                 0x05 

#define AUDIO_TOTAL_IF_NUM                      0x02
#define USBD_CFG_MAX_NUM                        1
#define USBD_ITF_MAX_NUM                        1

uint8_t USBD_DeviceDesc[USB_SIZ_DEVICE_DESC] =
  {
    0x12,                       /*bLength                */
    USB_DEVICE_DESCRIPTOR_TYPE, /*bDescriptorType = 0x01 */
    0x00,                       /*bcdUSB USB 2.0         */
    0x02,
    0x00,                       /*bDeviceClass           */
    0x00,                       /*bDeviceSubClass        */
    0x00,                       /*bDeviceProtocol        */
    USB_OTG_MAX_EP0_SIZE,       /*bMaxPacketSize = 64    */
    LOBYTE(USBD_VID),           /*idVendor               */
    HIBYTE(USBD_VID),           /*idVendor               */
    LOBYTE(USBD_PID),           /*idVendor               */
    HIBYTE(USBD_PID),           /*idVendor               */
    0x20,                       /*bcdDevice v1.20        */
    0x01,
    USBD_IDX_MFC_STR,           /*Index of manufacturer string   */
    USBD_IDX_PRODUCT_STR,       /*Index of product string        */
    USBD_IDX_SERIAL_STR,        /*Index of serial number string  */
    USBD_CFG_MAX_NUM            /*bNumConfigurations             */
  }