
Specification
NET2270 USB Interface Controller
______________________________________________________________________________
NetChip Technology, Inc., 2003
335 Pioneer Way, Mountain View, California 94041
TEL (650) 526-1490
FAX (650) 526-1494
http://www.netchip.com
Rev 3.6, April 17, 2003
70
9.1.7 Get Configuration Descriptor
The NET2270 can support a variety of configurations, interfaces, and endpoints, each of which is defined by the
descriptor data returned to the host. The local CPU has the responsibility of providing this data to the NET2270
when the host requests it.
This example has one configuration, and two interfaces. The first interface defines one Bulk OUT endpoint at
address 1 with maximum packet size of 512 and one Interrupt IN endpoint at address 82h (endpoint number = 2)
with a maximum packet size of 8. The second interface defines one Bulk OUT endpoint at address 3 with maximum
packet size of 512.
Note that all interface and endpoint descriptors are returned in response to a Get Configuration Descriptor request,
and for this example, 48 bytes are returned.
Offset
Number of
Bytes
Description
Suggested Value
Configuration Descriptor
0
1
Length
09h
1
1
Type (configuration)
02h
2
2
Total length returned for this configuration
0030h
4
1
Number of Interfaces
02h
5
1
Number of this configuration
01h
6
1
Index of string descriptor describing this configuration
00h
7
1
Attributes
bit 7 = 1
bit 6 = Self-Powered
bit 5 = Remote-Wakeup
bits 4:0 = Reserved
Determined by Local CPU
8
1
Maximum USB power required (in 2 mA units)
Determined by Local CPU
Interface 0 Descriptor
0
1
Size of this descriptor in bytes
09h
1
1
Type (interface)
04h
2
1
Number of this interface
00h
3
1
Alternate Interface
00h
4
1
Number of endpoints used by this interface
(excluding Endpoint 0)
02h
5
1
Class Code
FFh
6
1
Sub Class Code
00h
7
1
Device Protocol
00h
8
1
Index of string descriptor describing this interface
00h