Using Generic USB Controllers"
bLength 0x09 Descriptor size in bytes (9)
bDescriptorType 0x04 Descriptor type (INTERFACE)
bInterfaceNumber 0x00 Interface Number
bAlternateSetting 0x00 Alternate Setting Number
bNumEndpoints 0x01 Number of endpoints in this interface
bInterfaceClass 0x02 Class (communication)
bInterfaceSubclass 0x02 Subclass code (abstract control model (ACM))
bInterfaceProtocol 0x01 Protocol code (V.25ter, common AT commands)
iInterface 0x00 Interface string index (no string defined)
.
1
bFunctionLength 0x05 Descriptor size in bytes (5)
bDescriptorType 0x24 CS_INTERFACE
bDescriptorSubtype 0x00 Header functional descriptor
bcdCDC 0x0110 CDC specification release number in BCD format (1.1)
1
bFunctionLength 0x04 Descriptor size in bytes (4)
bDescriptorType 0x24 CS_INTERFACE
bDescriptorSubtype 0x02 Abstract Control Management Functional
Descriptor
bmCapabilities 0x02 Support for the SET_LINE_CODING,
SET_CONTROL_LINE, and GET_LINE_CODING
requests and the SERIAL_STATE notification.
1
bFunctionLength 0x05 Descriptor size in bytes (5)
bDescriptorType 0x24 CS_INTERFACE
bDescriptorSubtype 0x06 Union Functional Descriptor
bMasterInterface 0x00 The controlling interface for the union (bInterfaceNumber
of a Communication or Data Class interface in this
configuration)
bSlaveInterface0 0x01 The controlled interface in the union (bInterfaceNumber of
an interface in this configuration)Table 16-3: Example descriptors for a full-speed CDC device (Sheet 2 of 4).