CM109 Datasheet, PDF (16/36 Pages) C-Media Electronics – USB I/O Controller

CM109
High Integration / Low Cost USB Audio Controller
for PC Internet Phone
7.3.1 HID Descriptor
HID Interface Descriptor
Offset
Field
Size
0
bLength
1
1 bDescriptorType 1
2 bInterfaceNumber 1
3 bAlternateSetting 1
4 bNumEndpoints 1
5
bInterfaceClass
1
6 bInterfaceSubClass 1
7 bInterfaceProtocol 1
8
iInterface
1
Value (Hex)
Description
09
Size of this descriptor: 9 byte
04
INTERFACE descriptor type
03
Number of Interface: 3
00
alternate 0
01
Number of endpoints used by this
Interface: 1
03
HID Interface Class
00
No Subclass
00
Must be set to 0
00
Index of a string descriptor that
describes this interface.
HID Descriptor
Offset
Field
0
bLength
1 bDescriptorType
2
bcdHID
4
bCountryCode
5 bNumDescriptors
6 bDescriptorType
Size
1
1
2
1
1
1
7 wDescriptorLength 2
Value (Hex)
Description
09
Total 9 Bytes
21
HID Descriptor Type
0100 HID class version 1.00
00
01
22
Report Descriptor
0030
Numeric expression that is the total size
of the optional descriptor: 48 Bytes
Interrupt IN Endpoint Descriptor
Offset
Field
Size Value (Hex)
Description
0
bLength
1
07
Total 7 Bytes
1 bDescriptorType 1
05
ENDPOINT Descriptor Type
2 bEndpointAddress 1
83
IN Endpoint
Endpoint number = 3
3
bmAttributes
1
03
Interrupt endpoint type
4 wMaxPacketSize 2
0004 Maximum packet size: 4 bytes
6
bInterval
1
20
32ms
Date: 08/Sep/2005
- 15 -
Version: 1.3a