Posted on May 28, 2015 at 17:47When i developing custom USB device, I vent into trouble and at end I isolated a problem:
First: USB device answer for this packet is ''Success''
Setup Packet
Offset Field Size Value Description
0 bmRequestType 1 23h
4..0: Recipient ...00011 Other
6..5: Type .01..... Class
7: Direction 0....... Host-to-Device
1 bRequest 1 01h
2 wValue 2 0014h
4 wIndex 2 0001h
6 wLength 2 0000h
Second: and answer to following packet is ''Cancelled''
Setup Packet
Offset Field Size Value Description
0 bmRequestType 1 40h
4..0: Recipient ...00000 Device
6..5: Type .10..... Vendor
7: Direction 0....... Host-to-Device
1 bRequest 1 04h
2 wValue 2 0207h
4 wIndex 2 0000h
6 wLength 2 0000h
What cause different reaction of an USB device?
Framework is the USB_OTG_library, F407 processor, USBluzer sniffer.
GeorgD
