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CoaxPress support #88

Open gkasprow opened 3 months ago

gkasprow commented 3 months ago

We get more and more requests for support of CoaxPress cameras. There are several options:

  1. Use EEM FMC carrier and CoaxPress FMC from Kaya (or design our own)
  2. Make a dedicated DIOT card with simple CoaxPress Rx IC and stream data using MGT Rx lane (requires Kasli-DIOT, which have MGT routed to DIOT slots)
  3. Make a simple CoaxPress to SFP adapter. The only issue is that CoaxPress Rx IC requires an uplink LVCMOS line. So, it has to be connected to FPGA IO. We will do it in Kasli-DIOT (we will use the RATE_SEL line), but that approach won't work for the existing Kasli as it is. Existing Kasli would need simple rework - connect FPGA test point with SFP pad.
  4. We could use CoaxPress to SFP adapter and MGT Tx line to stream 40Mb/s uplink data, but that would require some extra work on firmware but would keep compatibility with all Kasli versions
nkrackow commented 1 month ago

We were also evaluating CoaXPress cameras but in addition to the closed standard (not sure how important with an external IC) the camera manufacturers have proprietary settings/telemetry channels via CoaXPress that you'd have to reverse engineer for any camera since they usually want to sell their custom flavored frame grabber as well... Also electrically the interface looks more annoying than shielded twisted pairs in one cable like you see in all other high-speed digital interfaces.

sbourdeauducq commented 1 month ago

It's not that much of a closed standard (seems easy to obtain the docs for free if you ask) and the licensing fee is quite reasonable for using the trademarks legally. The custom ICs only take care of the electrical interface, then it goes into GT transceivers. If you want to complain about this sort of thing: the much more expensive, disgusting, vendor locking-in, spyware-laden, Windows-only Altium trashware used for many Sinara projects is a much bigger issue. Hamamatsu are quite cooperative regarding ARTIQ support for their cameras. It should be easy to get info about any CXP vendor commands we may need. We plan to start implementing CXP seriously in 1-2 weeks (i.e. right after WRPLL is finished and the ARTIQ-8 release) using the hello-fpga CXP FMC card and EFC.

gkasprow commented 1 month ago

@sbourdeauducq We have ~20 engineers who use Altium. Three of them, including me, know Kicad. We are far more productive with Altium than with Kicad. It makes no economic sense to shift to a much worse tool. That would require training - one gets productive after two months with Kicad (we use it for clients that pay for it, i.e. CERN). Just multiply 17 2 engineer salary. And then add +100% of time spent on every project. Another issue is SI/PI verification, which doesn't work well for Kicad. We use Hyperlynx/SIWave for nearly every project. Altium is cheap. It is cheaper than one month for an engineer to work half-time in business in Poland. In addition, we get massive discounts on Ansys and Altium tools at the WUT (academic license for open projects). Finally, we use excellent Altium CERN libraries. After translating it to Kicad, they need a lot of manual work. So unless someone pays us extra to design in Kicad, we will continue with Altium.

gkasprow commented 1 month ago

your comment makes no sense at all.

gkasprow commented 1 month ago

Why does the Altium license prohibit us from having nice things? We are implementing all the changes and fixes the community requires. We happily design and produce nearly every piece the HW community asks for—for free—because we have public funding and our own time. Viewing does not require a license - you can do it even online. You can post your designs using whatever tool you want. You can also make Altium - Kicad translation and continue with Kicad. I often take Kicad designs and convert to Altium because it's far more productive for me. So just because you want, we should make a massive effort and lower our productivity... Would you switch your entire toolchain to another just because I want to? We have to live with the tools we have. Perfect is the enemy of good

sbourdeauducq commented 1 month ago

Well it seems that for example the EEM latchup issue is not going to get fixed, and if I want to fix it myself I have to pay those c***ts at Altium Ltd and Microsoft, plus handle the various concomitant IT security problems, just because the vendor lock-in strategy their MBA came up with worked. It's pretty disgusting.

gkasprow commented 1 month ago

Of course this latchup will be fixed in next revision.

gkasprow commented 1 month ago

I can give you temporary access to the license if that helps.