PCI-Express drivers with Xilinx FPGA?

It would really help if you told us what kit you're talking about. Most of us don't have the time to search out the manufacturer based on the little bit of info you've given us.

It's a Spartan-3/PCI-Express Starter Kit.

Don

The development kit allows the designer to create a custom PCIe interface. Within the PC architecture, the system expects that the software that will interface to this board will provide the driver.

Unfortunately, one cannot just develop a board and plug it into the PC, expecting built-in support for unknown functionalty.

You can choose not to "install the hardware" on your PC and still have diagnostic access to the PCIe space. The Avnet-taught PCIe session (about 4 hours, hands-on) used a freeware PCIe snoop utility - I don't find my notes but may come across them later - to verify the configuration settings that were applied in the FPGA.

If you do anything with the interface, software needs to be involved on the PC end. If you perform DMA, where do they go to or come from? If you perform register accesses, how are those registers physically mapped?

It would be ideal if we could just hook hardware up to a PC and have something happen without involving software. We're not there.

- John_H

Well, normally I would have used some type of microcontroller. The only reason I chose this version of FPGA is that I needed a large amount of I/O (over 250) and the Spartan-3/PCIe version had enough for my application. They also offer Spartan-3A and Virtex versions that include programming cables, but they didn't have enough I/O. The Digikey description said I was getting a programming cable with this model, but when I enquired as to why I didn't receive one, they said it was a misprint. I didn't realize that the PCIe interface was the only thing available for communication and downloading.

So I guess the upshot is that there is no other way to download my program except through the PCIe and there is no existing software that allows me to do that. So apparently I must develop some sort of drivers myself. I'm OK with doing that, but I guess I need more information. Can you recommend a source?

Don

While you will still need a driver and api/control software to interface to your board via the PCIe port, what you may be looking for is a Xilinx programming cable to load your bit file into the FPGA.

I didn't realize you were using the board as a non-PCIe device, just a general FPGA development board with a large number of I/O. This board is designed to operate stand-alone as well. I am a little disappointed they didn't include the embedded USP programming interface found on other boards.

I would also recommend the Platform Cable USB programming cable (as opposed to the Parallel-IV or a home-built Parallel-III compatible cable) because the power is supplied by the USB connection and the Vref - not used on the Parallel-III - gives a good range of acceptable voltages for any future development.

Maybe you can push Digikey for a discount on the cable thanks to their poor description. If not, maybe going direct to the Xilinx online store would be a better route.

- John_H

Aha! Brilliant! That's just what I'm looking for (I think) and well worth the $150 if it solves my problem. Thanks to everyone...I owe you a beer.

Don