AK5374 Datasheet, PDF (35/51 Pages) Asahi Kasei Microsystems – 24-bit Stereo ADC with USB Interface

4.6.3 Type I Format Type Descriptor
Offset
0
1
2
3
4
5
6
7
8
11
14
17
20
Field
bLength
bDescriptorType
bDescriptorSubtype
bFormatType
bNrChannels
bSubFrameSize
bBitResolution
bSamFreqType
tSamFreq[0]
tSamFreq[1]
tSamFreq[2]
tSamFreq[3]
tSamFreq[4]
Size Value
1 0x17
1 0x24
Description
Size of this descriptor in bytes
CS_INTERFACE
1 0x02
FORMAT_TYPE
1 0x01
FORMAT_TYPE_I
1 0x02
Two channel
1 0x02
Two bytes per slot
1 0x10
16 bits
1 0x05
Five frequencies
3 0x001F40 8000Hz
3 0x003E80 16000Hz
3 0x007D00 32000Hz
3 0x00AC44 44100Hz
3 0x00BB80 48000Hz
4.6.4 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 0x00C0
1 0x01
1 0x00
1 0x00
Description
Size of this descriptor in bytes
ENDPOINT descriptor
Endpoint 1, IN direction
Isochronous, synchronous, not shared
2byte*48sample*2ch=192 byte/frame
One packet every frame (Must be set to 1)
4.6.5 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
4.7 Operational Alternate Setting 6
4.7.1 Standard Audio Streaming Interface Descriptor
(Alt = 6: St, 16bit, 8k/11.025k/16k/22.05k /32k/44.1k)
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 0x06
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
MS1197-E-00
- 35 -
[AK5374]
2010/05