Amino and HW_Slices

[dan]

Not sure why that would be?

[dan]

There are some new bits and pieces in the repo now, including a space model of the PCIe connector based suggestion, a shot of the core board knocked up in PADS and a new file about connecting these boards via long distance xlinks.

Note that the little PCB stubs sticking out beyond the connector on the right hand side of the space-model-2.jpg picture are supposed to be able to connect to the corresponding connector on another core board (e.g. there would be teeth there), so multiple core boards can be chained via xlinks (albeit having each one twisted 90 degrees with respect to the previous one (e.g. in a coil).

[Interactive_Matter]

It is quite nice looking. The board seems quite big though - but perhaps it is just the photo.

I am a bit puzzled by

These could be easily used to build a 1 IN to 3 OUT XMOS-Link HUB using a 2 layer PCB and an XS1-L1-128TQFP. The HDMI connector and the LVDS drivers would be a slice board, not on the main core board.

This is again very understandable to keep the sytem as modular as possible.
But I have some arguments against it (not to claim that they render the concetp completely irrelevant:

• The XLINK is such an prominent concept for XMOS so that I would not really bring it to an optional board (even though not many people will use it).
• A XLINK is often used to expand the ports. But if two XLINK daughter boards eat up 1 connector on each board I got again two ports - so I only get more processing power. If I understand it correctly you would need 4 boards to gain more connector - but then you got only 4 connectors - the same you got with 2 boards, amgically connected over JTAG (to not block any ports - I know that it probably will not work).

Should the HDMI connectors come factory installed?

Or is it so that factory installed HDMI connectors solve the big port/small port problem since you can offer the smaller ports over HDMI while offering at the same time the bigger ports over PCIe. But wouldn't that eat up to much board real estate or is it too expensive?

Somehow this big ports/small ports problem remains puzzling.

Marcus

[Corin]

Hi Marcus,

Thanks for pointing this out. I have updated that page on the repository.

Cheers,
Corin

[Interactive_Matter]

Hmm,

somehow I cannot decode how this solves the 'you need at least 5 boards to have 4 usable output problem'. What am I missing?

Marcus

[dan]

* Each core board has 4 connectors that carry I/O, two of which also carry JTAG.

* Two interconnected core boards (whether using the tab that stick s out or the HDMI daughter boards) will have 2x4-2 = 6 connectors.

* N interconnected core boards have Nx4- (N-1)x2 = 2xN+2 connectors

So it scales linearly...?

The xlink interconnecting two core boards only consumes one of the 4 connectors on each board. If you don't need the LVDS, then you just plug the two core boards together directly, using that little tab that sticks out.

Does that make sense and does it answer your question?

[Interactive_Matter]

Uhmmm,

it actualy confuses me a bit more. I thought each board has 2 PCIe connectors, not 4???
At least that is what I read from https://github.com/xcore/hw_slicekit_sy ... nector.rst

It seems that I am really missing an important point.

[dan]

ack, I see why you are confused. Its two connectors per CORE, so 4 connectors for the L2 core board!

I have changed the heading of that section in the page you linked to - check it and let me know if this clears matters up.

Sorry about that!

[Interactive_Matter]

If my confusion is helping anybody - then it is good for something ;)

Thanks I have ognored the two connectors per core.

Now everything is clear

[dan]

So Marcus,

Do you (or anyone else for that matter) have further questions or concerns about the current proposal? I'm not sure whether all your questions re the xlinks were answered or not.

Cheers,

Dan