AK5374 Datasheet, PDF (33/51 Pages) Asahi Kasei Microsystems – 24-bit Stereo ADC with USB Interface

4.4.5 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]
4.5 Operational Alternate Setting 4
4.5.1 Standard Audio Streaming Interface Descriptor (Alt = 4: St, 8bit, 8k/11.025k/16k/22.05k)
Offset
0
1
2
3
4
5
6
7
8
Field
bLength
bDescriptorType
bInterfaceNumber
bAlternateSetting
bNumEndpoints
bInterfaceClass
bInterfaceSubclass
bInterfaceProtocol
iInterface
Size Value
1 0x09
1 0x04
1 0x01
1 0x04
1 0x01
1 0x01
1 0x02
1 0x00
1 0x00
Description
Size of this descriptor in bytes
INTERFACE descriptor
Index of this interface
Index of this setting
Endpoint 1
AUDIO
AUDIO_STREAMING
Not used. Must be set to 0.
Null string
4.5.2 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 0x0002
Description
Size of this descriptor in bytes
CS_INTERFACE descriptor
AS_GENERAL
Unit ID of terminal (Output Terminal ID)
Interface delay
PCM8
4.5.3 Type I Format Type Descriptor
Offset
0
1
2
3
4
5
6
7
8
11
14
17
Field
bLength
bDescriptorType
bDescriptorSubtype
bFormatType
bNrChannels
bSubFrameSize
bBitResolution
bSamFreqType
tSamFreq[0]
tSamFreq[1]
tSamFreq[2]
tSamFreq[3]
Size Value
1 0x14
1 0x24
1 0x02
1 0x01
1 0x02
1 0x01
1 0x08
1 0x04
3 0x001F40
3 0x002B11
3 0x003E80
3 0x005622
Description
Size of this descriptor in bytes
CS_INTERFACE
FORMAT_TYPE
FORMAT_TYPE_I
Two channels
One byte per slot
8 bits
Four frequencies
8000Hz
11025Hz
16000Hz
22050Hz
MS1197-E-00
- 33 -
2010/05