Hi,

I am working on the usb 2.0 project.

I am unable to find any indication of data length i.e.,
how do you get to know that you have rec'd/transmitted
the expected amount of data? How do you get to know the
end of data?

Pls help out with this issue.

Thank you,

Regards
Harish.

The answer is complicated, and depends upon the endpoint type. You should reference the USB 2.0 Specifications, which are available as free downloads from www.usb.org

Currently I am working on Control transfers (at the device side) and so control endpoint is my current interest. I have gone through the spec but I am not sure with data end. Nowhere it says about the amount of data that device would receive/require to send.

Thank you for your reply.

i was also working on control transfer.i not know how to use buf1 to transmit data.can we exchange some ideas.

My Dear Friends,

Answer is very simple, did you both know what is Setup packet 8-Byte data indicate?
See USB2 Specification Table 9.2, 6th offset is 2-byte wLength. This wLength is give information to device how much data device have to transmit/receive in Data phase depend upon Dir(D7 bit of bmRequest) bit.

For more query and quick solution join my below community in linkedin.
http://www.linkedin.com/groups?gid=3825534&goback=%2Eanb_3825534_*2_*1_*1_*1_*1_*1%2Egna_3825534

Cheers.....
RC

Read usb2.0 spec .u will find sop(start of packet),start of frame and length of diferent tocken frames and all the thing u want

End of Data should be done before EOF and with respect to speed transfer of packets differ
but from endpoint descripter we can come to know
taking example of hi-speed
3 isochronous transfers allowed then interrupt then bulk till end
another thing is usb 2.0 work as half way bus
so even the speed in 60MB/s ,we will get only 30MB because half is used to get response from receiver.