Communication between 3 XC-1As

[m_y]

Ok so I'm going with 4 XC-1As so topology issues are avoided.

Regarding systems built out of multiple boards: whilst it's easy enough to build applications for this, booting it will be problematic. Here are some of the reasons: xgdb does not support multiple jtag chains; xflash does not support writing to systems with multiple jtag chains; the G4 boot is sensitive to start-up timing; we've observed some issues with some boards in these situations (issues which are being looked at now).

@m_y How problematic are we saying here? If I understand, I'm going to have to boot each of the boards up individually via usb, and all within a short space of time (~1 second)?

Yes. Or (and I haven't actually tried this myself) pull-down resistors on all the data lines should obviate the need for starting the boards up at the same time.

[dougxmos]

Just to clarify, although there's not currently a workaround for specifying the routing IDs or switch registers used by the mapper, we've been discussing this limitation internally and intend to provide a low-level API for manually configuring arbitrary networks of devices in our next major tools release.

[tomcarter259]

Yes. Or (and I haven't actually tried this myself) pull-down resistors on all the data lines should obviate the need for starting the boards up at the same time.

Ok I will look into the pull resistors. I think I saw a forum post about that somewhere. I have 4 XC-1As now so it's all systems go.

Thanks for your help and input everyone

[tomcarter259]

Sorry to drag up an old thread...just to let you know that I have put up projects with example code and walkthroughs of how to connect multiple XC-1As via Xlinks. Particularly @lilltroll as I think he asked for them.

Two boards: https://www.xcore.com/projects/dual-xc-1as

Four boards: https://www.xcore.com/projects/quad-xc-1as

All the code is hosted on github. Let me know if you have any problems :)