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v-usb only accept 8 bytes per packet?
Posted: Tue Oct 06, 2009 12:19 pm
by nhchmg
I want to implements a mass storage device,but the bulk command is 31 bytes,what can I do?
thanks advance.
Re: v-usb only accept 8 bytes per packet?
Posted: Thu Oct 08, 2009 6:53 pm
by nhchmg
default USB_BUFFSIZE = 11, I set USB_BUFFSIZE = 67,It' working
Re: v-usb only accept 8 bytes per packet?
Posted: Fri Oct 23, 2009 7:14 pm
by Saimon
Config your in and out endpoint to 8 bytes. bulk out endpoint will recive all 31 byte of command, but it take 4 transfer.
For more iformation this is my realization of bulk endpoints
http://depositfiles.com/files/00ar212ls
Re: v-usb only accept 8 bytes per packet?
Posted: Mon Oct 26, 2009 11:09 pm
by christian
The low level USB packets are always maximum 8 bytes for low speed devices. Larger blocks are transferred in chunks of 8 bytes. V-USB handles this more or less transparently, it calls usbFunctionRead() and usbFunctionWrite() for blocks of 8 bytes.