04:12 <rogandawes[m]> It is seen, and respected. 🫡🖖

05:45 <ldcd[m]> By chaining together the two PLLs and using the delay taps I can do phase modulation with a slew rate of 2.3 degrees/ns and a total travel of around 320 degrees on a 48MHz wave

05:51 <ldcd[m]> I'm thinking the ringing might be reducable by playing with the filter range parameter

05:51 <ldcd[m]> does anyone know the approximate bandwidths of the PLL filters?

06:24 <ldcd[m]> With FILTER_RANGE 1-4 I get progressively faster slew rates, with 5-6 I just get ringing when I flip from maximally negative to maximally positive code, but it seems likely my 1054z just isn't fast enough to catch it, 7 seems to ring so much it kicks it around a whole cycle

06:25 <ldcd[m]> I think that means higher filter ranges have narrower bandwidths?

06:25 <ldcd[m]> I need to remind myself how PLLs work

06:27 <ldcd[m]> Interestingly filter range 0 slews twice as fast as filter range 4 but has half the tuning range

06:29 <ldcd[m]> as if the feedback delay is not being applied and I'm just seeing the output delay

06:29 <ldcd[m]> and no ringing from the PLL

07:29 <ldcd[m]> Modulating it works, ish, but there are clearly glitches in the PLL output

07:30 <ldcd[m]> will need to look at this at work tomorrow with a faster scope, real probing, and a spectrum analyzer

07:31 <ldcd[m]> They could also be FIFO underruns, don't know what the behavior would be there

07:32 <ldcd[m]> No they go away if I play something in the 10 KHz range

07:33 <ldcd[m]> so probably actually the PLL

07:37 <ldcd[m]> https://gist.github.com/ld-cd/4d40cb4089b7b75b3397865e31fb3936

07:37 <ldcd[m]> (very rough)