7.3.6 Set Configuration
Table 7-16. Set Configuration
Value Meaning
0x00 OUT, Device
Byte
0
Field
bmRequestType
bRequest
wValueL
8051 Response
Read and stash byte 2, change
1
0x09 “Set_Configuration” configurations in firmware
2
CFG Config Number
3
wValueH
0x00
0x00
0x00
0x00
0x00
4
wIndexL
5
wIndexH
6
wLengthL
wLengthH
7
When the host issues the Set_Configuration request, the 8051 saves the configuration
number (byte 2 in Table Table 7-16), performs any internal operations necessary to sup-
port the configuration, and finally clears the HSNAK bit (by writing “1” to it) to terminate
the Set_Configuration CONTROL transfer.
Note
After setting a configuration, the host issues Set_Interface commands to set up the vari-
ous interfaces contained in the configuration.
7.3.7 Get Configuration
Table 7-17. Get Configuration
Byte
0
Field
bmRequestType
bRequest
wValueL
Value
Meaning
8051 Response
0x80 IN, Device
Send CFG over IN0BUF after
1
0x08 “Get_Configuration” re-configuring
2
0x00
0x00
0x00
0x00
3
wValueH
4
wIndexL
5
wIndexH
6
wLengthL
wLengthH
1
0
LenL
LenH
7
The 8051 returns the current configuration number. It loads the configuration number into
EP0IN, loads a byte count of one into EP0INBC, and finally clears the HSHAK bit (by
writing “1” to it) to terminate the Set_Configuration CONTROL transfer.
EZ-USB TRM v1.9
Chapter 7. EZ-USB CPU
Page 7-19
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