On Fri, Jun 17, 2011 at 1:07 PM, Uwe Bonnes <[email protected]> wrote: >>>>>> "Caleb" == Caleb Kemere <[email protected]> writes: > > Caleb> I've noticed previous threads where folks have used the > Caleb> synchronous FIFO mode of the FT2232H and gotten quite reasonable > Caleb> sustained transfer rates (15 MB/s). I'm struggling to get 6.5 > Caleb> MB/s (without the buffer on the chip filling up). Is this an > Caleb> issue of the asynchronous FIFO mode, or am I somehow not pulling > Caleb> data off on the PC fast enough? > > What direction is the transfer? Device to PC or PC to device?
Device to PC. (The device is a Spartan, I forget what kind.) > I only have experience with synchronous read at high rate. Is your hardware > fast > enough? Lookin at the datasheet, I see 80 Nanoseconds needed for each vyte by > the FT232 in FT245 Style Asynchronous FIFO Interface Mode. So if your > hardware adds another 80 ns, you will loose. We've set up the FPGA to stop sending if the FT2232H ever signals that its buffer is full. So that's what's happening. > Otherwise, how do you read on the PC side? Do yo do asynchronous reads like > in libftdi-1.0/src/ftdi_stream.c? I have been doing a loop of ftdi_read_data(). I'm just starting to play around with libftdi-1.0. thanks! – caleb -- libftdi - see http://www.intra2net.com/en/developer/libftdi for details. To unsubscribe send a mail to [email protected]
