I couldn't understand your query. What do you meant by initialize the FPGA from PC ? Are you trying a streaming application? What is this 1MB bitstream ? Are you programming FPGA using USB interface?
Could you please provide more details on this?
Are you trying to implement the interface explained in AN61345 - Implementing an FX2LP™- FPGA Interface with spartan6?
Yes I am programming FPGA using USB interface.
In other case, we have used USB controller in the past succesfully for program (initialize) old FPGAs, like Spartan3. The bitstream was less than 1Mbyte for this FPGA and never we had any problem.
Now we are trying initialize a Spartan6, the bitstream for program this FPGA is more than 1Mbyte, the problem have resulted when data is being transferred and spend 1 MByte, the usb controller driver hangs.
We don't know if the driver has any limit for transfer data.
Do you know what may be the reason that we can't transfer more than 1 Mbyte? if there is.
Thanks so much