ASAHI KASEI
[AK4571]
3.5.4.
Type I format type descriptor<Alternate Setting 1>
Offset
Field
blength
bDescriptorType
bDescriptorSubtype
bFormatType
bNrChannels
Size
Value
0x1D
0x24
0x02
0x01
0x02
Description
0
1
2
3
4
1
1
1
1
1
Size of this descriptor
CS_INTERFACE
FORMAT_TYPE
FORMAT_TYPE_I
Two channels
5
6
7
bSubFrameSize
bBitResolution
bSamFreqType
tSamFreq[0]
tSamFreq[1]
tSamFreq[2]
tSamFreq[3]
tSamFreq[4]
tSamFreq[5]
tSamFreq[6]
1
1
1
3
3
3
3
3
3
3
0x02
0x10
0x07
0x001F40
0x002B11
0x003E80
0x005622
0x007D00
0x00AC44
0x00BB80
Two bytes per slot
16 bits
Seven frequencies
8000Hz
11025Hz
16000Hz
22050Hz
32000Hz
44100Hz
48000Hz
8
11
14
17
20
23
23
3.5.5.
Endpoint descriptor
Field
Offset
Size
Value
0x09
0x05
0x02
0x09
Description
0
1
2
3
bLength
1
1
1
1
Length of this descriptor
ENDPOINT descriptor
Endpoint 2, OUT direction
Adaptive Isochronous,
bDescriptorType
bEndpointAddress
bmAttributes
4
6
7
8
wMaxPacketSize
bInterval
bRefresh
2
1
1
1
0x00C8
0x01
0x00
2byte*(48+2)sample*2ch=200byte/frame
1millisecond (Must be set to 1)
Unused
Unused
bSynchAddress
0x00
3.5.6.
Class-specific isochronous audio data endpoint descriptor
Offset
Field
Size
Value
Description
0
bLength
1
0x07
Size of this descriptor
1
2
3
4
5
bDescriptorType
bDescriptorSubtype
bmAttributes
bLockDelayUnits
wLockDelay
1
1
1
1
2
0x25
0x01
0x01
0x00
0x0000
CS_ENDPOINT
EP_GEN ERAL
Sample rate control
Unused
Unused
MS0153-J-02
2003/3
- 35 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
