Lucent Technologies USS-720 - Manual (Page 36)

5-10 Lucent Technologies Inc.
USS-720 Instant USB Preliminary Data Sheet, Rev. 5
USB-to- IEEE 1284 Bridge September 1999
13
USB Port (continued)
Interface 0, Alternate Setting 2 (I0:A2)
Table 11. Interface Descriptor, I0:A2
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 0x02 Value used to select this alternate interface.
4 bNumEndpoints Byte 0x03 Number of endpoints used by this descriptor.
5 bInterfaceClass Byte 0xFF Vendor specific.
6 iInterfaceSubClass Byte 0x00 —
7 bInterfaceProtocol Byte 0xFF Vendor specific.
8 iInterface Byte 0x00 Index to string describing this interface.
Table 12. Bulk Out Endpoint Descriptor, I0:A2: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.
Table 13. Bulk In Endpoint Descriptor, I0:A2:E2
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 0x82 This is an In endpoint, endpoint number 2.
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.
Table 14. Interrupt Endpoint Descriptor, I0:A2:E3
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 0x83 This is an In endpoint, endpoint number 3.
3 bmAttributes Byte 0x03 This is an Interrupt endpoint.
4 wMaxPacketSize Word 0x0004 Maximum data transfer size.
6 bInterval Byte 0x01 This pipe should be serviced every frame.