low cost xilinx prom burner?

For the serial prom, have you tried impact from the downloadable, no- cost webpack version of ISE? While the bitstream generation tools in that won't handle the larger parts, I'd be a little suprised if they limited impact. Or if they did, how about digilent's USB cable and software, for much less than Xilinx's cable (think "export" can do a prom via and svf file, but it would be worth double checking)?

As for the flash rom, I don't know what is most cost effective (what your time making it work is worth), but cheapest hardware would probably be to put some function in your fpga that can accept data over an external interface (spi?) and program it. Perhaps a small design that you download directly to the FPGA temporarily?

prom

use

whole

Thanks I'll try that.

Unfortunately I only have low speed serial links so it woudl take about an hour to transfer the flash contents.

Thanks, Clark

So run them faster when downloading the code.

Or use an additional link for this purpose.

Remember, jtag is just a synchronous serial interface, with a mode pin... there's no reason you can't get comparable throughput from a simple function temporarily downloaded into your FPGA. In fact you should be able to do better, as you could minimize the overhead.

an

I should have specified UART. Max I can get is 115 kbaud. So a 64MB flash would take about 6400 seconds.

I have USB once the system is up. I guess I could write a stub application with just enough code to get the USB up, but it won't fit in the FPGA block ram which then means: program prom, transfer stub app over RS-232, finish over USB.

Then don't use the UART. Make your own synchronous serial connection. You seem to be treating the jtag loader as somehow magic

- it isn't, it's still a synchronous serial connection with a download speed deteremined by it's clock rate.

The difference is that you can buy it already working, wheras this you would have to build, license, or locate in open-source form.

And start by looking here:

Interesting! Thanks for the link.