Paul Geraedts wrote on Oct 19th, 2020, 11:30pm:
This text explains recent changes in the Spectre interface: https://community.cadence.com/cadence_blogs_8/b/cic/posts/virtuoso-video-diary-p...
At the same time it does not describe the most recent Spectre (v20.1) interface, from [spectre -h pnoise]: Code:
22 noisetype=timeaverage Specifies computation of time-averaged or time-sampled noise information. Possible values are timeaverage, correlations, timedomain, pmjitter and sampled.
Possibly Andrew could shed some light on this?
Sorry for the delay - bit behind on my Designer's Guide posts...
That blog was written before the cleanup of the various modes related to sampling (timedomain, pmjitter). Some of the modes remain for legacy reasons - but the choices that are now used are timeaverage and sampled. The timeaverage mode is pretty much covered in the blog - unfortunately some of the terminology used in the noiseout
choice is rather confusing unless you're simulating an oscillator - for driven circuits, most likely the terms usb, lsb, am and pm don't mean so much. Usually you'd want to use "usb" in that case - this is equivalent to the old "sources" mode (mostly people didn't know what "sources" meant either, so that was not great terminology as well) - it's what you'd get on a spectrum analyser and is the easiest to understand. The other modes make more sense when you are (say) simulating the noise around a carrier frequency (e.g. an oscillator output) and you want to observe the noise in the upper sideband, the lower sideband, or find the AM or PM components from the two sidebands. This used to be computed via the "correlations" mode (under the hood from the UI), but it suffered from some accuracy problems (particularly with getting accurate AM noise).
The sampled mode allows you to compute the sampled output noise in various different ways; you can use "Edge Crossing", "Edge Delay" or "Sampled Phase" for the timing event; the first allows you to measure the sampled noise at one node based on a threshold crossing at another node (could be the same node); the Edge Delay allows you to measure the jitter delay between one node and another, and the Sampled Phase is essentially a way to strobe at an arbitrary time or set of times (i.e. the same as the old "timedomain" mode).
Not entirely sure what info you were after - but hopefully that's a high level summary that covers things well enough?