EZ-USB Datasheet, PDF (131/334 Pages) Cypress Semiconductor – The EZ-USB USB Integrated Circuit

Table 7-5. Get Status-Interface
Byte
Field
0 bmRequestType
1 bRequest
2 wValueL
3 wValueH
4 wIndexL
5 wIndexH
6 wLengthL
7 wLengthH
Value
Meaning
8051 Response
0x81 IN, Endpoint
Load two bytes into IN0BUF
0x00 “Get Status”
Byte 0 : zero
0x00
Byte 1 : zero
0x00
0x00
0x00
0x02 Two bytes requested
0x00
Get_Status/Interface is easy: the 8051 returns two zero bytes through IN0BUF and clears
the HSNAK bit. The requested bytes are shown as “Reserved (Reset to zero)” in the USB
Specification
7.3.2 Set Feature
Set Feature is used to enable remote wakeup or stall an endpoint. No data stage is
required.
Table 7-6. Set Feature-Device (Set Remote Wakeup Bit)
Byte
Field
0 bmRequestType
1 bRequest
2 wValueL
3 wValueH
4 wIndexL
5 wIndexH
6 wLengthL
7 wLengthH
Value
Meaning
0x00 OUT, Device
0x03 “Set Feature”
0x01 Feature Selector:
Remote Wakeup
0x00
0x00
0x00
0x00
0x00
8051 Response
Set the Remote Wakeup bit
The only Set_Feature/Device request presently defined in the USB specification is to set
the remote wakeup bit. This is the same bit reported back to the host as a result of a Get
Status-Device request (Table 7-3). The host uses this bit to enable or disable remote
wakeup by the device.
Page 7-10
Chapter 7. EZ-USB CPU
EZ-USB TRM v1.9