CM6571 Datasheet, PDF (22/63 Pages) C-Media Electronics – USB 2.0 full speed-compliant

CM6571
USB Audio Sound Chip
configuration descriptor
Offset
Field
Size Value (Hex)
Description
0
bLength
1
09
Descriptor length
1
bDescriptorType
1
02
Configuration Descriptor
2
wTotalLength
2
011D
Total length of data returned for this configuration:
285 Bytes
Number of interfaces supported by this Configuration:
00: Control
4
bNumInterfaces
1
04
01: ISO-Out
02: ISO-In
03: INT-In (HID)
5
bConfigurationValue 1
01
Configuration value
6
iConfiguration
1
00
Index of string descriptor describing this configuration
7
bmAttributes
1
80
Attributes(Bus Powered)
8
bMaxPower
1
32
Maximum power consumption from bus = 100mA:
8’h32 (50x2 mA) (PWRSEL_2 = 1)
audio control interface 0 descriptor 0
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
Descriptor length
04
Interface Descriptor
00
Interface number
00
Alternate interface
00
Number of endpoint used by this interface
01
Audio Interface Class
01
Subclass code: AUDIO_CONTROL
00
Protocol code
00
Index of string descriptor describing this interface
class-specific AC interface header descriptor
Offset
Field
Size Value (Hex)
Description
0
bLength
1
0A
Descriptor length
1
bDescriptorType
1
24
CS_INTERFACE descriptor type
2
bDescriptorSubtype 1
01
HEADER descriptor subtype
3
bcdADC
2
0100 Audio Device Class specification release number
5
wTotalLength
2
0066
Total length of data returned for the class-specific
Audio Control interface descriptor:
7
bInCollection
1
02
The number of Audio Stream interfaces in the
collection: 02
8
baInterfaceNr(1)
1
01
Interface number of the first Audio Stream interface in
the collection
9
baInterfaceNr(2)
1
02
Interface number of the second Audio Stream interface
in the collection
class-specific input terminal descriptor (USB stream), ID=01
Offset
Field
Size Value (Hex)
Description
0
bLength
1
0C
Descriptor length
1
bDescriptorType
1
24
CS_INTERFACE descriptor type
2
bDescriptorSubtype 1
02
INPUT_TERMINAL descriptor subtype
3
bTerminalID
1
01
Terminal ID
4
wTerminalType
2
0101 Terminal Type: USB Stream
6
bAssocTerminal
1
00
Associate Terminal
7
bNrChannels
1
02
Number of channel Stereo : 02
8
wChannelConfig
2
0003
D0: Left Front (L)
D1: Right Front (R)
10
iChannelNames
1
00
Index of string descriptor describing the name of the
first logical channel
Revised: Nov. 2012
Page 22 / 63
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