Configuration Descriptor; Interface Descriptor Alternate Setting - Dascom 1500 User Manual

Interfaces

Configuration Descriptor

Offset Field
0 bLength
1 bDescriptorType
2 wTotalLength
4 bNumInterfaces
5 bConfigurationValue
6 iConfiguration
7 bmAttributes
8 MaxPower

Interface Descriptor Alternate Setting

Offset Field
0 bLength
1 bDescriptorType
2 bInterfaceNumber
3 bAlternateSetting
4 bNumEndPoints
5 bInterfaceClass
Size Value Description
Byte 0x09 Size of this descriptor in bytes.
Byte 0x02 Configuration descriptor type.
Word 0x0019 No. of bytes in this configura-
tion. This includes the configu-
ration descriptor plus all of
interface and endpoint descrip-
tors.
Byte 0x01 Project SDM500 has 1 inter-
face.
Byte 0x01 Value to use as an argument to
SetConfiguration() request to
select this configuration.
Byte 0x00 Index of string descriptor
describing this configuration.
Byte 0xC0 Configuration characteristics:
D7 : Reserved (set to 1) D6 :
Self-powered D5 : Remote
wakeup D4 . . . D0 : Reserved
(set to 0) (Self Powered /
RemoteWakeup UnSupport)
Byte 0x31 Maximum power consumption
of this configuration. (98mA)
Size Value Description
Byte 0x09 Size of this descriptor in bytes.
Byte 0x04 Interface descriptor type.
Byte 0x00 Number of Interface.
Byte 0x00 Value used to select alternate
setting for the interface identi-
fied in the prior field.
Byte 0x02 Number of endpoints used by
this interface (excluding End-
point 0).
Byte 0x07 Class code (Printer class).
USB interface
B-7