Kasli DRTIO satellite: link does not come up

[cjbe]

With the current gateware the Kasli DRTIO satellite does not ever get to the 'link up' state - it hangs after "Si5324 is locked".

With the Kasli satellite running 2ca3fda the DRTIO link comes up properly, running dd21c07 or later and it hangs.
This happens independent of which version the master is running (i.e. the with the master at HEAD, and using the old satellite gateware, everything works fine).

This seems likely to be due to the clocking changes in misoc between 103bb3a8 and 4c010df2 .

[marmeladapk]

It may be connected with what I saw - on some variants of Kasli I had rolling restarts of Artiq (but not misoc) once I got Si5324 is locked. Next week I'll investigate it more.

[sbourdeauducq]

This is likely due to the siphaser MMCM input being connected to a clock that is not 125MHz anymore.
It could be connected directly to the clock input buffer instead, that can be routed to multiple clock components. Frequency is different on Kasli (62.5) and Sayma (125, can keep using system clock).

[sbourdeauducq]

@cjbe Can you test again?

[cjbe]

@sbourdeauducq that fixed it