CoaxPress support

[gkasprow]

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]

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]

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.