I am trying to simulate a MS design (analog blocks + digital controller) with UltraSim. I care a LOT about accurate estimation of supply current. So this is what I notice:
I have an accurate IDD in ANALOG mode (i.e. no partitioning), but scrambled results with MS (and below) modes. Interestingly, the overall simulation behavior is sane, even in MS mode (correct voltages in different nodes). It is only the supply current that is in trouble.
Naturally, I'd like to use MS mode for the speedup. Does anyone have a word of advice on this?
BTW, asked some friends around, and apparently, this issue is known.