W99681CF Datasheet, PDF (32/78 Pages) Winbond – JPEG USB Dual Mode Camera Chip

W99681CF
6
bInterfaceSubClass
7
bInterfaceProtocol
8
iInterface
1
0x00 Digital Video Camera subclass code
1
0x00 Protocol code. No class specific protocol.
1
0x00 No interface string
Table 7.8 W99681CF Data-In Endpoint Descriptor
Offset Field
Size Value
0
bLength
1
0x07
1
bDescriptorType
1
0x05
2
bEndpointAddress
3
bmAttributes
4
wMaxPacketSize
6
bInterval
1
0x81
1
0x01
2
0x00
1
0x01
Description
Size of this descriptor in bytes
Endpoint Descriptor Type
Endpoint number. Direction is set to IN.
Isochronous transfer type
Default zero bandwidth
Interval in milliseconds for polling endpoint for
data transfers
The W99681CF Video interface includes 16 alternate settings that allow the Data-In endpoint
bandwidth to be varied decreasingly from 8 Mbps down to 0.5 Mbps in descending 0.5 Mbps steps
such that the device driver can request subsequently smaller bandwidth quantities. A separate
interface descriptor and its associated endpoint are included for each setting. When the host requests
the Configuration Descriptor, all 16 pairs of interface and endpoint descriptors for alternate setting
should follow the interface and endpoint descriptors for the default alternate setting zero.
The W99681CF supports the Get Interface and Set Interface requests to report or select a specific
alternate setting for the Video interface.
Table 7.9 W99681CF Video Interface Alternate Setting 1-16 Interface Descriptor
Offset Field
Size Value Description
0
bLength
1
bDescriptorType
2
bInterfaceNumber
3
bAlternateSetting
1
0x09 Size of this descriptor in bytes
1
0x04 Interface Descriptor Type
1
0x00 Number of interface
1
1-16 Alternate setting 1-16 for this interface
(Note 1)
4
bNumEndpoints
1
0x01 Number of endpoints used by this interface
5
bInterfaceClass
6
bInterfaceSubClass
7
bInterfaceProtocol
8
iInterface
Note 1. Refer to Table 7.11.
1
0x00 Image interface class code
1
0x00 Digital Video Camera subclass code
1
0x00 Protocol code. No class specific protocol.
1
0x00 No interface string
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