lxSelectedUpdateIgnore works on layout instances.
There does not seem to be an equivalent "ignore" function for schematic instances...
Here is the scenario:
Typically in layout there are elements which are artifacts of the layout, i.e. they may be dummy transistor cells which are required by the technology.
In many of these instances, when I insert such layout instances I break VLX correspondence, and have to set the ignore property on these "dummy" cells.
Eventually I have to add them into the schematic to pass LVS, but in doing so, again I break VLX correspondence (this time from the schematic side).
After adding these "dummy" transistors in schematics (and breaking the correspondence), if I were to Update from source, the dummy transistors
will be instantiated in the layout, and setting the binding between the "dummy" layout instances and the corresponding schematic instances is normally
not feasible (it is possible, but in general dummy cells from a given library typically don't contain any connectivity information, i.e. net/terminal/pins).
Hope this makes sense, in general it seems it would be useful to have the ignore property on the source side as well. But perhaps there are other
approaches that circumvent these issues. I know it is also possible to have two different schematic views associated with one layout, but having two
views adds more complexity and becomes more error prone, I rather just have one schematic and one corresponding layout view. If you have other
suggestions please let me know.
Thanks in advance,
-f