Lucent Technologies USS-720 manual Interface Descriptors, Bulk Out Endpoint Descriptor, I0A0E1

USS-720Instant USB	Preliminary Data Sheet, Rev. 5
USB-to-IEEE1284 Bridge	September 1999

USB Port (continued)

Interface Descriptors

The USS-720 supports a single interface with three alternate settings.

Interface 0, Alternate Setting 0 (I0:A0)

Table 6. Interface Descriptor, I0:A0

Offset	Field	Size	Value	Description
0	bLength	Byte	0x09	Size of this descriptor in bytes.
1	bDescriptorType	Byte	0x04	Interface descriptor type.
2	bInterfaceNumber	Byte	0x00	Zero-based value identifying the number of this interface.
3	bAlternateSetting	Byte	0x00	Value used to select this alternate interface.
4	bNumEndpoints	Byte	0x01	Number of endpoints used by this descriptor.
5	bInterfaceClass	Byte	0x07	Printer class.
6	iInterfaceSubClass	Byte	0x01	Printer subclass.
7	bInterfaceProtocol	Byte	0x01	Unidirectional interface.
8	iInterface	Byte	0x00	Index to string describing this interface.
Table 7. Bulk Out Endpoint Descriptor, I0:A0:E1
Offset	Field	Size	Value	Description
0	bLength	Byte	0x07	Size of this descriptor in bytes.
1	bDescriptorType	Byte	0x05	Endpoint descriptor type.
2	bEndpointAddress	Byte	0x01	This is an Out endpoint, endpoint number 1.
3	bmAttributes	Byte	0x02	This is a Bulk endpoint.
4	wMaxPacketSize	Word	0x0040	Maximum data transfer size.
6	bInterval	Byte	0x00	Does not apply to bulk endpoints.

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