This article is dedicated to the gentleman I sat next to at lunch at CDNLive a while back who Is a CAD engineer busily supporting a large user community, but had been stumped by the question "How do I create a delta marker in VIVA?"
I'm sure he is not alone. Delta markers in IC6.1.5 ViVA (Virtuoso Visualization and Analysis Tool) are very powerful, but they can be a bit hard to find and unless you read the documentation (or this blog), you may never unlock all their useful capabilities. That's what I'm here for...
Note that the method for creating delta markers changed in IC6.1.5 ISR8, so if the instructions below doesn't work for you, you may need to update your Virtuoso version.
First, I want to direct your attention to a handy little document I put together a while ago which provides a 1-page Quick Reference to the most useful bindkeys in ViVA. Markers in ViVA are all about bindkeys, and for delta markers, you have to know just where and in what combination to use those bindkeys.
The basic summary goes like this:
This is a special kind of delta marker. To create it, press A somewhere, then B somewhere else. You'll get 2 point markers labelled A and B and a delta label between them. Now, wherever you press A or B again, the original A or B marker will move to that spot and the delta values will update. Only one A/B marker allowed per window, but you can click the right mouse button (RMB) on the delta dimension line and select "Convert A/B Marker to Delta" so you can keep that information on the graph and continue playing the A/B game at another location.
If you have put down a bunch of markers (point, vertical, horizontal), you can select 2 or more of them (using Ctrl-click to select multiple markers) and then press Shift-D to get delta markers between all the selected markers. The cool thing about this is that you can mix point markers with vertical or horizontal markers to get delta values from a point to a line.
This will probably be your most commonly-used method of creating delta markers. Simply select a point, vertical or horizontal marker (M, V, H) and then wherever you press the D key, you will get a 2nd marker of that type and the delta between. Since when you create a point, vertical or horizontal marker, it remains selected, you can use the sequence M, D, D, D... or V, D, D, D... or H, D, D, D... to get multiple markers with delta values between them with just a few keystrokes.
A few extra tips
Use the menu pick Marker->Show Delta Child Labels (or RMB in a blank area of the graph->Show Delta Child Labels) to toggle the visibility of the point marker labels at either end of the delta and only display the delta values. (IC6.1.5 ISR12) Helps reduce clutter on the graph.
Delta values between vertical markers now show up in the Vertical Marker table (IC6.1.5ISR12). Choose Window->Assistants->Vert Marker Table or use the built-in MarkerTable workspace to open the marker table. You can use Marker->Export->Vertical Markers to create a CSV file with all the marker values.
Watch them in action
If any of the above is not clear, watching this video clip should help. Note that this short clip is part of a longer video available here, covering everything you need to know about using all types of markers in ViVA. If video fails to open, click here.
For AC sim plots, it would be handy to have automatic markers at 3dB, gain cross over, phase cross over frequencies.
You made my day! Your cheatsheet is now part of my cube wall. Thank you
This is a very helpful little whitepaper that I believe may improve the productivity of using ViVa significantly. This whitepaper is helpful at any level of cadence user.