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Simulators >> Circuit Simulators >> how to update waveform automatically
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Message started by sugar on Aug 18^th, 2006, 3:41am

Title: how to update waveform automatically
Post by sugar on Aug 18^th, 2006, 3:41am

In spectreRF waveform window, how to update waveform automatically?

Title: Re: how to update waveform automatically
Post by Andrew Beckett on Aug 20^th, 2006, 3:40pm

Automatically? Automatically upon what?

You can always set up the things to be plotted to be added to the outputs pane, and then they can be plotted automatically after a simulation completes - but I'm not sure exactly what you're after.

Andrew.

Title: Re: how to update waveform automatically
Post by sugar on Aug 20^th, 2006, 4:54pm

Andrew,

I mean update waveforms during simulation.
Suppose my simulation takes long time and I want to watch where my simulation goes as the simulation is going on.
You know I am lazy, I don't want to frequently click 'Window->Update Results' in the Waveform Window to see the current simulation result. I wish the Waveform Window could automatically update simulation results, say every 10 simulation steps, thus I can just sit there and watch the waveforms I am interested in.

Title: Re: how to update waveform automatically
Post by ACWWong on Aug 21^st, 2006, 2:14am

I guess the "march" option on the waveform is the one you want, but i think that ceased to work with the abolition of spectreS. I've been clicking "plot outputs" during simulation or "Window->Update Results" in the waveform window for many years now... you get used to it... and its not a massive overhead is it ?

Title: Re: how to update waveform automatically
Post by rf-design on Aug 23^rd, 2006, 12:26am

I only guess it has to do with the SW architecture. Possible because now Wavescan and AWD have to be supported they are incompatible for online updating (live results). That is the price possible to pay for eating companies.

Title: Re: how to update waveform automatically
Post by Geoffrey_Coram on Aug 28^th, 2006, 6:58am

rf-design wrote on Aug 23^rd, 2006, 12:26am:

That is the price possible to pay for eating companies.

But Wavescan was developed internally to Cadence (as was SpectreRF), so I don't see that "eating companies" is at all relevant here.

Title: Re: how to update waveform automatically
Post by jbdavid on Aug 30^th, 2006, 12:26am

"marching" waveforms used too much compute time and made the simulation slow down.. Not a real problem for 4-20 transistors.. but who does that few transistors at one time now..
so you can use "plot outputs" and that will do a ONE Time interruption of the simulation (unless its wavescan sometimes)
to generate the plot up to that point..
such a trick has been taught in the Cadence classes for 6-7 years now.. so should be pretty universal..
(you have at least ONE person on staff who has been thru (or trained to teach) the Artist -- oops ADE class, right?)
jbd

Title: Re: how to update waveform automatically
Post by Geoffrey_Coram on Aug 30^th, 2006, 6:17am

ACWWong wrote on Aug 21^st, 2006, 2:14am:

No, but why can't there be a timer so that Wavescan would automatically do this every N minutes? Maybe I've got the plot up in a different window, and I just glance over at it every now and then while my mouse stays in a window where I'm doing some other work.

I guess "march" may have been overkill for this sort of function.

Title: Re: how to update waveform automatically
Post by jbdavid on Aug 30^th, 2006, 11:10pm

Wouldn't it be nice if the output data would stay in the window where you left it, instead of popping up to what ever other desktop you were working on while you waited for the sim to finish..???
naw.. the Cadence App is the most important, so its OK to interrupt what ever else you were working on!!
jbd

Title: Re: how to update waveform automatically
Post by Ken Kundert on Aug 30^th, 2006, 11:17pm

That behavior is controlled by the window manager, not the application. This one is not Cadence's fault.

-Ken

Title: Re: how to update waveform automatically
Post by jbdavid on Aug 30^th, 2006, 11:27pm

I don't entirely buy it.. but if so, why not make a recommendation to the KDE team or Sun to fix it?
Or tell users how to configure their WM so it doesn't happen if they find it annoying..

Ah but what can we do about it now but file SR"s??
jbd

Title: Re: how to update waveform automatically
Post by rf-design on Sep 1^st, 2006, 12:22am

Come on guys,

the update could be controlled by

1. User interaction trought the window control
2. Timer action
3. Background process which control the visibility relevance of the transient results

It is a matter of specifying and exercising the software. There is no limitation here. To put more on top of that what I think is the difference between imagine and what is actual implemented here is my list:

1. Online update of relevant data

Methods a: Update a each user pixel coordinate on the horizontal axis. So if the transient data update equal to the lenght of one pixel there is a redraw. That is exactly resource optimized. More you could not see.

Method b: Define an observation window within the result march. This window is centered around the actual or last transient time time point. For instance -3..+1% of the total simulation time.

One of the problems with existing waveform tools is further that they are data point driven instead of user coordinate driven. So if you have significant more transient points than user pixels in your zoom range there is a multiply paint into the same horizontal but possible many vertival pixels. All that lead to bad user experience.

I think the major issue is that the users did not specify the SW. One way could be an open specification forum, technical organized like Wiki, which will give the SW vendors the major direction. The one which implemented it in the best way get the cash.

Title: Re: how to update waveform automatically
Post by Andrew Beckett on Sep 20^th, 2006, 3:18am

Actually, it can be done with manual intervention already.

It's fairly straightforward to write some SKILL code to effectively issue the "Plot Outputs" command on a regular (wall clock) basis. Personally I think it would get pretty irritating, but the thing to do is to ask Cadence. Asking in this forum won't do it...

Users do get to influence the design of the software by contact customer support, and then enhancement requests are generated, and some of these get implemented - of course, it needs to be a balance - over complication versus ease of use versus speed...

The old marching waveforms were rubbish - you couldn't do much with the waveform window. So losing them was not a big loss (they had a big performance hit too). I can see an argument for a regular update of the waveform database if you really wanted it (obviously you'd not want it
too regularly). That said, I can't see the big problem with just hitting the plot outputs button once in a while to see what changed. The main reason for observing the waveforms like this is for long simulations - you're not exactly going to be sitting in front of the waveform glued to it for 8 hours are you?

Andrew.

Title: Re: how to update waveform automatically
Post by rf-design on Sep 20^th, 2006, 2:56pm

Andrew,

I know that "feature request" is the way to get new functionality. I am working for a medium size IDM. I wanted to probe signals in the extracted view in IC4.4.6 and made a feature request. It took about 3 years to put it into IC5.0.32. The issue was that I would be satified at the early time to get the node number which I could use in the "Result Browser" to plot the internal node of the "extracted view". But the issue is that the node corrospondence list, generated at the LVS run, was only in binary format. So the layouters have to set pins everywhere the circuit designer wants to see signals. I also had painful experience with "Spectre" in the early 90's becide that I respect that it is now one of the best simulators.

Reiner

Title: Re: how to update waveform automatically
Post by sugar on Jan 1^st, 2007, 5:50pm

hi all,
thank you for your replies and happy new year
yet I have another question:
is there a bandkey or can I set a bandkey to update the waveform window?

Title: Re: how to update waveform automatically
Post by ACWWong on Jan 2^nd, 2007, 2:39am

i don't know of a bindkey, but you should be able to set one up... try contacting cadence for assistance.