CM6571 Datasheet, PDF (25/63 Pages) C-Media Electronics – USB 2.0 full speed-compliant

CM6571
USB Audio Sound Chip
12
iMixer
1
00
Index of string descriptor describing this Mixer Unit
standard as interface descriptor (interface 1, alternate 0)
Offset
Field
Size Value (Hex)
Description
0
bLength
1
09
Descriptor length
1
bDescriptorType
1
04
Interface Descriptor
2
bInterfaceNumber 1
01
Interface number
3
bAlternateSetting 1
00
Alternate interface
4
bNumEndpoints
1
00
Number of endpoint used by this interface
5
bInterfaceClass
1
01
Audio Interface Class
6
bInterfaceSubClass 1
02
Subclass code: AUDIO_STREAM
7
bInterfaceProtocol 1
00
Protocol code
8
iInterface
1
00
Index of string descriptor describing this interface
standard as interface descriptor (interface 1, alternate 1)
Offset
Field
Size Value (Hex)
Description
0
bLength
1
09
Descriptor length
1
bDescriptorType
1
04
Interface Descriptor
2
bInterfaceNumber 1
01
Interface number
3
bAlternateSetting 1
01
Alternate interface
4
bNumEndpoints
1
01
Number of endpoint used by this interface
5
bInterfaceClass
1
01
Audio Interface Class
6
bInterfaceSubClass 1
02
Subclass code: AUDIO_STREAM
7
bInterfaceProtocol 1
00
Protocol code
8
iInterface
1
00
Index of string descriptor describing this interface
class-specific as general interface descriptor (interface 1, alternate 1)
Offset
Field
Size Value (Hex)
Description
0
bLength
1
07
Descriptor length
1
bDescriptorType
1
24
CS_INTERFACE descriptor type
2
bDescriptorSubtype 1
01
AS_GENERAL descriptor subtype
3
bTerminalLink
1
01
Link to Output USB Stream
4
bDelay
1
01
Sync delay: 1ms
5
wFormatTag
2
0001 PCM 16-bits format
class-specific as type format descriptor (interface 1, alternate 1)
Offset
Field
Size Value (Hex)
Description
0
bLength
1
1D
Descriptor length
1
bDescriptorType
1
24
CS_INTERFACE descriptor type
2
bDescriptorSubtype 1
02
Format descriptor subtype
3
bFormatType
1
01
Format type 1
4
bNrChannels
1
02
Number of channel 02 : stereo
5
bSubframeSize
1
02
2 bytes per slot
6
bBitResolution
1
10
Bit resolution : 16-bits
7
bSamFreqType
1
07
7 sampling rates
8
tSampFreq(1)
3
001F40 Sampling rate: 8kHz
11
tSampFreq(2)
3
002B11 Sampling rate: 11.025kHz
14
tSampFreq(3)
3
003E80 Sampling rate: 16kHz
17
tSampFreq(4)
3
005622 Sampling rate: 22.05kHz
20
tSampFreq(5)
3
007D00 Sampling rate: 32kHz
23
tSampFreq(6)
3
00AC44 Sampling rate: 44.1kHz
26
tSampFreq(7)
3
00BB80 Sampling rate: 48kHz
Revised: Nov. 2012
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