AccessRunner ADSL-USB Modem Device Set Data Sheet
Table 4-1. Device Descriptors
Offset
Field
bLength
Size
Value
Default
(Hex.)
Description
0
1
2
1
1
2
Number
Constant
BCD
12
01
Size of this descriptor in bytes.
bDescriptorType
bcdUSB
DEVICE Descriptor Type.
0110
USB Specification Release Number in Binary-Coded Decimal (i.e.,
2.10 is 0x210). This field identifies the release of the USB
Specification that the device and its descriptors are compliant with.
4
bDeviceClass
1
Class
00
Class code (assigned by USB).
If this field is reset to 0, each interface within a configuration
specifies its own class information and the various interfaces
operate independently.
If this field is set to a value between 1 and 0xFE, the device
supports different class specifications on different interfaces and the
interfaces may not operate independently. This value identifies the
class definition used for the aggregate interfaces. (For example, a
CD-ROM device with audio and digital data interfaces that require
transport control to eject CDs or start them spinning.)
If this field is set to 0xFF, the device class is vendor specific.
Subclass code (assigned by USB).
These codes are qualified by the value of the bDeviceClass field.
If the bDeviceClass field is reset to 0, this field must also be reset to
0.
If the bDeviceClass field is not set to 0xFF, all values are reserved
for assignment by USB.
Protocol code (assigned by USB). These codes are qualified by the
value of the bDeviceClass and the bDeviceSubClass fields. If a
device supports class-specific protocols on a device basis as
opposed to an interface basis, this code identifies the protocols that
the device uses as defined by the specification of the device class.
5
6
bDeviceSubClass
bDeviceProtocol
1
1
SubClass
Protocol
00
00
If this field is reset to 0, the device does not use class specific
protocols on a device basis. However, it may use class specific
protocols on an interface basis.
If this field is set to 0xFF, the device uses a vendor specific protocol
on a device basis.
7
bMaxPacketSize0
1
Number
40
Maximum packet size for endpoint zero (only 8, 16, 32, or 64 are
valid).
8
idVendor
2
2
2
1
1
1
1
ID
ID
0572
CAFE
0001
01
Vendor ID (assigned by USB).
10
12
14
15
16
17
idProduct
Product ID (assigned by the manufacturer).
Device release number in binary-coded decimal.
Index of string descriptor describing manufacturer.
Index of string descriptor describing product.
Index of string descriptor describing the device’s serial number.
Number of possible configurations.
bcdDevice
BCD
iManufacturer
iProduct
Index
Index
Index
Number
02
iSerialNumber
bNumConfigurations
03
01
4-2
Conexant
100427B
CONEXANT [ CONEXANT SYSTEMS, INC ]
