AK5374 Datasheet, PDF (36/51 Pages) Asahi Kasei Microsystems – 24-bit Stereo ADC with USB Interface

4.7.2 Class-specific Audio General Interface Descriptor
Offset
0
1
2
3
4
5
Field
bLength
bDescriptorType
bDescriptorSubtype
bTerminalLink
bDelay
wFormatTag
Size Value
1 0x07
1 0x24
1 0x01
1 0x02
1 0x01
2 0x0001
Description
Size of this descriptor in bytes
CS_INTERFACE descriptor
AS_GENERAL
Unit ID of terminal (Output Terminal ID)
Interface delay
PCM
4.7.3 Type I Format Type Descriptor
Offset
0
1
2
3
4
5
6
7
8
11
14
17
20
23
Field
bLength
bDescriptorType
bDescriptorSubtype
bFormatType
bNrChannels
bSubFrameSize
bBitResolution
bSamFreqType
tSamFreq[0]
tSamFreq[1]
tSamFreq[2]
tSamFreq[3]
tSamFreq[4]
tSamFreq[5]
Size Value
1 0x1A
1 0x24
Description
Size of this descriptor in bytes
CS_INTERFACE
1 0x02
FORMAT_TYPE
1 0x01
FORMAT_TYPE_I
1 0x02
Two channels
1 0x02
Two bytes per slot
1 0x10
16 bits
1 0x06
Six frequencies
3 0x001F40 8000Hz
3 0x002B11 11025Hz
3 0x003E80 16000kHz
3 0x005622 22050Hz
3 0x007D00 32000Hz
3 0x00AC44 44100Hz
4.7.4 Standard Endpoint Descriptor
Offset
0
1
2
3
4
6
7
8
Field
bLength
bDescriptorType
bEndpointAddress
bmAttributes
wMaxPacketSize
bInterval
bRefresh
bSynchAddress
Size Value
1 0x09
1 0x05
1 0x81
1 0x0D
2 0x00B4
1 0x01
1 0x00
1 0x00
Description
Size of this descriptor in bytes
ENDPOINT descriptor
Endpoint 1, IN direction
Isochronous, synchronous, not shared
2byte*45sample*2ch=180 byte/frame
One packet every frame (Must be set to 1)
4.7.5 Class-specific Isochronous Audio Data Endpoint Descriptor
Offset
0
1
2
3
4
5
Field
bLength
bDescriptorType
bDescriptorSubtype
bmAttributes
bLockDelayUnits
wLockDelay
Size Value
1 0x07
1 0x25
1 0x01
1 0x01
1 0x00
2 0x0000
Description
Size of this descriptor in bytes
CS_ENDPOINT
GENERAL
Sample rate control
Unused
[AK5374]
MS1197-E-00
- 36 -
2010/05