AK5374 Datasheet, PDF (34/51 Pages) Asahi Kasei Microsystems – 24-bit Stereo ADC with USB Interface

4.5.4 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 0x002E
1 0x01
1 0x00
1 0x00
Description
Size of this descriptor in bytes
ENDPOINT descriptor
Endpoint 1, IN direction
Isochronous, synchronous, not shared
1byte*23sample*2ch=46 byte/frame
One packet every frame (Must be set to 1)
4.5.5 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]
4.6 Operational Alternate Setting 5
4.6.1 Standard Audio Streaming Interface Descriptor (Alt = 5: St, 16bit, 8k/16k/32k/44.1k/48k)
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 0x05
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
4.6.2 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
MS1197-E-00
- 34 -
2010/05