EZ-USB Datasheet, PDF (140/334 Pages) Cypress Semiconductor – The EZ-USB USB Integrated Circuit

7.3.6 Set Configuration
Table 7-16. Set Configuration
Byte
Field
0 bmRequestType
1 bRequest
2 wValueL
3 wValueH
4 wIndexL
5 wIndexH
6 wLengthL
7 wLengthH
Value
Meaning
0x00 OUT, Device
0x09 “Set_Configuration”
CFG Config Number
0x00
0x00
0x00
0x00
0x00
8051 Response
Read and stash byte 2, change
configurations in firmware
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
Field
0 bmRequestType
1 bRequest
2 wValueL
3 wValueH
4 wIndexL
5 wIndexH
6 wLengthL
7 wLengthH
Value
Meaning
0x80 IN, Device
0x08 “Get_Configuration”
0x00
0x00
0x00
0x00
1 LenL
0 LenH
8051 Response
Send CFG over IN0BUF after
re-configuring
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