fpga4fun.com

I just received my Xylo LM board and the first sample worked fine. Always a good sign. The docs are very clear. Some additional comments in the verilog would have been appreciated, given the target audience is presumably so new to the material. But I'm making it through.

I was a bit disappointed to see that schematics weren't included. Yes, I know they can be deduced given the FPGA mappings. But that's kind of the point: If they can be deduced, then why not just give the schematic?

Also, I would have thought the source code for the Cypress part would have been included. Is it and I've just missed it?

This is kind of weird to sell such a closed dev kit. It really means that this platform isn't really a dev kit: it's a closed platform on which to watch a few exaaples run, and then slightly modify those and watch them run again. You can't readily take a design from being proven on the dev board to an actual new design because so much has to be reinvented.

Am I misunderstanding? Have I just missed the source code and schematic?

Thanks

The docs are published online at http://www.knjn.com/docs/ so people can get a sense of what the boards can do - and can't - before buying them. But you're right to point out that the boards are not completely open. You also failed to mention that KNJN doesn't provide the source code for the FPGAconf app either.

By calling something a devboard, you imply it's wide open. Full schematics, full sources, the works.

Similarly, when GM calls something "a car", they don't mention that it can drive up a hill. I kind of assume that. We'd all be a bit surprised to purchase a car and find out it couldn't make it up a hill. True, the car manufacturer never said on their website it could go up a hill, but people just assume based on passed experience.

A bit pedantic, I know...

But knjn does call it a dev board, and they do say it comes with "docs, tutorials, source files and tools" There is nothing there to warn a person that has purchased countless dev boards over 20 years that this one will be any different.

I'm not unhappy with the board--the docs are really good. , I'm just bugged by the extra work I'll have to go through to get a design from this board to a real board.

What do you mean by a "real board"?

By "real board" I mean a board that is designed to go into an application--such as an autonomous model airplane. I use the Xylo board to test a part of a design becuase it is "known good" hardware. Then, once the software is worked out on the known good hardware, I make my own board that is specific to an application, and then prove that piece out using known good software.

As I'm sure you are aware, bringing up new SW on new HW is a challenge. So it's quickest to prove things out in steps.

I tried to write an app tonight for the PC that can talk to the xylo board. The Cypress USB dll for c# doesn't know how to talk to the Xylo CyUSB.sys driver. And when I install the CyUSB.sys driver from Cypress, it can enumerate the xylo board, but then the FPGAconf.exe doesn't work.

Any idea why the Cypress tools cannot see the xylo board when the the xylo-provided CyUSB.sys is the driver?

Yes it is probably because the GUID used by the Cypress tool is different from the one FPGAconf uses by default.

Try that: open a command-line window, and type "FPGAconf /?". You can see the list of parameters accepted. One of them allows to contol the GUID. Use it to match the one used by Cypress (you can find it in the .inf file of the Cypress driver).

Something has gone bad again. The Xylo board and the FPGAConf app are still happy and talking to each other, but for some reason the .NET SuiteUSB and CyUSB.DLL stuff quit working. So I guess that would be "not so suiteUSB".. I have no clue why. And no nothing I can do will get it working again. It looks like others are having this problem on the Cypress forum.

Any ideas? It's not so much a GUID thing, as even when I revert to all Cypress drivers, the DLL still doesn't see the FX2 part. It's a cypress thing, I'm pretty sure.

I'll update when/if I learn more.

Idea: did you check which driver is loaded when you plug the board in?

Unfortunately, the right drivers are indeed being loaded (CyUSB) on the FPGAConfig. I've not tried the other driver even once, so chances of it sneaking in are close to nil. But it's a good thing to double check, thanks!

Actually both KNJN and Cypress tools use the same driver (CyUSB) but with a different GUID. FPGAconf can be made working with a custom GUID, but I'm not sure about the Cypress .net suite. Do you know what GUID they are using?

Which version of FPGAconf do I need to use a custom GUID?
I have version 2.08.07 and does not give me an option to change GUID.

Thanx,
Rolf

Can't remember what version you need to get the GUID, but you can always download the latest version if you remember your board's startup-kit link. If you forgot the link, just send us an email and we'll resend the link to you.