usb_device_interface_struct_t

This structure provides information about each alternate setting interface for the current interface. All structures should be placed in the “usb_device_descriptor.c” file.

Prototype:

typedef struct _usb_device_interface_struct
{
    uint8_t                          alternateSetting;
    usb_device_endpoint_list_t       endpointList;
    void*                            classSpecific;
 } usb_device_interface_struct_t;

Description:

• alternateSetting: The alternate value of this interface.

• endpointList: endpoint list structure. See the usb_device_endpoint_list_t structure.

• classSpecific: The class-specific structure pointer.

Prototype:

typedef struct _usb_device_endpoint_list
{
    uint8_t                          count;
    usb_device_endpoint_struct_t*    endpoint;
} usb_device_endpoint_list_t;

Description:

• count: Number of endpoints in the current interface.

• endpoint: Endpoint information structure.

This is an example for the composite device MSD + CDC:

MSD:

usb_device_interface_struct_t g_mscDiskInterface[] =
{
    {
        0,
        {
            USB_MSC_DISK_ENDPOINT_COUNT,
            g_mscDiskEndpoints,
        },
    },
};

Number “0” holds the alternate setting value of the MSD interface.

USB_MSC_DISK_ENDPOINT_COUNT is the endpoint number for MSD interface when the alternate setting is 0.

“g_mscDiskEndpoints” is the endpoint detailed information structure. See usb_device_endpoint_struct_t section for more information.

CDC:

For control interface:

/* Define interface for communication class */
usb_device_interface_struct_t g_cdcVcomCicInterface[] =
{
    {
        0,
        {
            USB_CDC_VCOM_CIC_ENDPOINT_COUNT,
            g_cdcVcomCicEndpoints,
        },
    }
};

Number “0” holds the alternate setting value of the CDC control interface.

USB_CDC_VCOM_CIC_ENDPOINT_COUNT is the endpoint number for control interface when the alternate setting is 0.

“g_cdcVcomCicEndpoints" is the endpoint detailed information structure. See usb_device_endpoint_struct_t section for more information.

For data interface:

/* Define interface for data class */
usb_device_interface_struct_t g_cdcVcomDicInterface[] =
{
    {
       0,
       {
           USB_CDC_VCOM_DIC_ENDPOINT_COUNT,
           g_cdcVcomDicEndpoints,
       },
    }
};

Number “0” holds the alternate setting value of the CDC data interface.

USB_CDC_VCOM_DIC_ENDPOINT_COUNT is the endpoint number for control interface when the alternate setting is 0.

“g_cdcVcomDicEndpoints” is the endpoint detailed information structure. See usb_device_endpoint_struct_t section for more information.

Parent topic:USB composite device structures