As it turns out, a work-around of the segmentation fault is reusing the already *refined* PSS data (instead of the unrefined PSS data). So enabling MIC in both PSS analyses. The periodic steady-state will get even more refined now, so basically it has the same result as decreasing psaratio.

Paul

Hi Baolin,

Thanks for your quick reply! Don't worry about the crash, the work-around does the trick nicely. The netlist that I'm using contains a lot of stuff which I'm not allowed to pass on. Another similar example will probably show the same behaviour. Hopefully somebody from Cadence is reading this as well (Andrew? ;). But thanks for your offer!

Yes, MIC seems very useful. I've read somewhere that it can get the noise floor to levels of about -200dB! Great for oscillator design.

So am I right that FDTD, as implemented in Spectre, is a refinement method? So that always a (coarse) periodic steady-state has to be calculated first with Shooting-Newton (the combination Harmonic Balance & FDTD is probably a bit silly, right?). So MIC is as exact as FDTD (otherwise, why would you want to use MIC)?

I still don't really get when to use which method (FDTD/MIC). Could you give me some general advise?

I don't want to bother you too much with it though. Do you know of any good article on FDTD as implemented in Spectre?

Thanks again,

Paul

Hi Baolin,

I've never understood that both methods are so similar! I think I'll use MIC exclusively from now on, as it seems to me that MIC is an improvement on all fronts. Or do I overlook situations in which using the 2nd-order method can have advantages?

I have seen the book that you mentioned in our library. I'll have a look at it.

Baolin, thanks for your posts. You have been a great help! (To get accurate information on these topics is pretty hard for a regular user as myself.)

Paul