CM108AH Datasheet, PDF (17/27 Pages) C-Media Electronics – Highly Integrated USB Audio I/O Controller

CM108AH
Highly Integrated USB Audio I/O Controller
7.3.2 HID Descriptors
HID Interface Descriptor
Offset
0
1
2
3
4
5
6
7
8
Field
bLength
bDescriptorType
bInterfaceNumber
bAlternateSetting
bNumEndpoints
bInterfaceClass
bInterfaceSubClass
bInterfaceProtocol
iInterface
Size
1
1
1
1
1
1
1
1
1
Value (Hex)
Description
09
Size of this descriptor: 9 bytes
04
Interface descriptor type
03
Interface number: 3
00
Alternate: 0
01
Number of endpoints used by this interface: 1
03
Interface class: HID
00
Subclass: no
00
Must be set to 0
00
String descriptor index that describes this interface
HID Descriptor
Offset
0
1
2
4
5
6
7
Field
bLength
bDescriptorType
bcdHID
bCountryCode
bNumDescriptors
bDescriptorType
wDescriptorLength
Size
1
1
2
1
1
1
2
Value (Hex)
09
21
0100
00
01
22
0030
Description
Total: 9 bytes
HID descriptor type
HID class version 1.0
Report descriptor
Total size of the optional descriptor: 48 bytes
Interrupt IN Endpoint Descriptor
Offset
0
1
2
3
4
6
Field
bLength
bDescriptorType
bEndpointAddress
bmAttributes
wMaxPacketSize
bInterval
Size
1
1
1
1
2
1
Value (Hex)
07
05
83
03
0004
2
Description
Total: 7 bytes
Endpoint descriptor type
In Endpoint Number = 3
Interrupt endpoint type
Maximum packet size: 4 bytes
2ms
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