<sb0>
larsc: what happens if we double the SYSREF frequency (with the DAC in one-shot synchronization mode)?
<sb0>
I want to DDMTD the SYSREF going into the FPGA, but the MMCM needs at least 10MHz
<sb0>
I could double the FPGA SYSREF only, but it makes things a bit more complex
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<sb0>
or maybe a better idea is to DDMTD a 150MHz output, use the DDMTD results to align that to the RTIO clock, and then align SYSREF (with a known number of 7043 slips) to the RTIO counter
<sb0>
then there are no issues with minimum MMCM PFD frequencies, and the MMCM parameters are generally more reasonable
<sb0>
we can even get crazy resolutions easily and then we know exactly how bad ultrascale is
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<key2_>
whitequark: when generating something with nmigen, is there a way to define the name of the top module ?
<key2_>
There are signals that I don't want that end up there, and some signal that I want that are names foo$123 instead of their real name, (they come from Records())
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<whitequark>
key2_: yes, you can use rtlil.convert(name="...")
<whitequark>
as for signals that end up in ports, there is nothing that can be done right now other than tying them to reset value explicitly
<whitequark>
(this is a bug that needs to be fixed)
<key2_>
name="..." being ?
<key2_>
the names of the signals you want ?
<key2_>
ah na
<key2_>
when you do ports=[...]
<key2_>
there is no way to keep only those port and keep their name ?
<key2_>
or rather a dict
<key2_>
would be a good option
<key2_>
something like port={"signame" : foo.bar}
<sb0>
hartytp: what kind of DAC sync issues did you get at 2.4GHz exactly and what was the sync window like?
<sb0>
(sync window == timing range in which you can move SYSREF without affecting sync)
<whitequark>
key2_: no, "name" is for calling top module
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<key2_>
yeah, i figured, i was talking about port then
<key2_>
question is how could we have (only) the signals we requested on the port ?
<whitequark>
you currently cannot
<key2_>
and how can we have the name we want, especially when there is collision with this name
<key2_>
is it possible to force the name to be deterministic ?