pnoise jitter Jee plot button disappeared

Please post a screenshot - not clear which form you're talking about (ideally show the pss, pnoise and direct plot forms).

Thanks,

Andrew

Hi Andrew,

sure!

I just took a look in both IC618 ISR5 and ISR10 (the latest). The way that sampled noise was handled was changed during IC617 as part of the overall noise revamp, to try to ensure that what you get actually makes sense and to (try to) remove ambiguity about the meaning of the various output items.

Jee is a number - it's the RMS jitter in seconds in the specified bandwidth - so I'm not sure it really makes sense to plot. You can use the "Add to outputs" and then you'll get the number in the ADE output pane.

Not sure what you're expecting it to plot? Plotting a single number doesn't make a huge amount of sense - what would the x-axis be?

Regards,

Andrew.

Jee vs. df is the jitter in seconds in a bandwidth of 1Hz per spot offset frequency.

Saying that Jee is a number would be the same as saying that the Phase Noise is a number... I think.

I know there is (or was) a way to plot it. As a proof, a screenshot from a slide I did a few years ago:

Actually the Jee(df) can be plotted by computing from the edge phase noise L(df) in dBC/Hz the function sqrt(  10**(Lscript/10) / (2*pi**2 * f0**2)  ); but I was surprised not to see it anymore.

As you can see on my screenshot, there was a "pnoise jitter" section, with its Jee section and "Plot" button. Now I see "pnoise sampled" instead, without any "plot" button... Weird !!

Why is it different ?

I didn't know what you meant by "df". Now it makes a bit more sense (although not entirely sure what practical use knowing the Jee in a 1Hz bandwidth is versus frequency, but OK). 

What changed is that you were previously using the old Jitter analysis flow in an older version prior to the cleanup. Let me check if there was a good reason why the plot was removed.

Regards,

Andrew.

The reason of this post is all the PNoise sims I did 1 month ago return "Eval Error".

I have lost a day and am still reworking my testbenchs to suit to the new tool... This is really not nice from Cadence!

OK, but you have made a fairly major switch in the version you're using. I believe you've switched major versions (the change happened in IC617 ISR17, together with a SPECTRE17.1). So whilst it's "not nice", there was a good reason for the changes and presumably you've changed software versions very close to tapeout. It can't have stopped working without you changing something...

Absolutely you need to find a way of getting what you want here, I understand. Also, a better channel for this kind of support question really is customer support. I did a quick bit of research and found that we even have an article on this: Why can't I plot Jee anymore from the Direct Plot form? - it even explains why we don't plot the curve any more because it was misleading.

Andrew.

I was able to perform this sim 2 weeks ago; not sure the switch was so high... But anyway, what has been done has been done.

I made my research on the customer support but did not find any related article... My fault.

Thanks for you help Andrew.

Sorry if my last reply came across as a bit blunt. I didn't mean to - tone is very hard to capture in a written forum!

Anyway, hopefully you have a way forward and sorry for the frustration this has caused you.

Kind Regards,

Andrew.

Sorry if my last reply came across as a bit blunt. I didn't mean to - tone is very hard to capture in a written forum!

Anyway, hopefully you have a way forward and sorry for the frustration this has caused you.

Kind Regards,

Andrew.

So am I Andrew, was a bit blunt as well. Just a bit frustated indeed, and furthermore the first thing we do in that case is to think yourself probably did a mistake, before thinking this is because of the tool..

Best regards.