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Re: [usb] Hi

** Proprietary **

the SETUP packet which consists of 8 bytes has a specific structure(9.3, 248 page - USB2.0 spec). if u look into the 9th chapter, what the 8 bytes represent for each command(GET_DESCRIPTOR, SET_CONFIGURATION etc) is given there. but for every command, the 7th & 8th byte always represent the no. of bytes that the device has to transfer during the data transfer stage. so when the setup data packet is received by the device, check those last 2 bytes. whatever is the value, those many no. of bytes u have to transfer for GET_DESCRIPTOR.

>>> govindsrajan@hotmail.com 06/05/02 06:24AM >>>
Hi,

   When I set a device descriptor, the USB spec says the payload
   (wLength) is a variable number of bytes. How do I know the actual
   no of bytes and their values ? This is sent as payload in the data
   phase of a control transfer.

   Thanks
   Govind
 
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