LVS report

dai

hi @Matthias
i see lvs result show cell is correct(mean all net matched) but still has one net on "netlist browser marker' marked red. i don't know why. Do you have any suggestion for this case?

thanks you
dai

Matthias

If the top level circuit is green I'd not worry too much about the red mark.

I guess I will not get access to the test case. If I had it I could debug the real issue - any maybe add a better message to the error (I assume it's rather a disguised warning), or avoid it.

Matthias

dai

hi Matthias
yes, i'm sorry i can not send you the gds but this is not important.
BTW, do you have any way to find where is the shorted net when we have a shorted net(ex: vdd vs vss)?.
when i click on the net it show on whole layout so it is hard to find where is shorted point.

thanks you.
dai

Matthias

@dai The net tracer feature is basically able to show the shortest path (in terms of shape jumps) between two points you click at.

In order to use it however you need to set up the connectivity in the net tracer ("Tools/Edit Layer Stack").
For a metal short it will be sufficient to set up the metal connectivity only. This unfortunately is a step that is different from LVS and you cannot use the LVS connectivity for that.

If you have done so, open the net tracer ("Tools/Trace Net"). Then use "Trace Path": click on one shape on the first net and then on one from the second net. The search is incremental and can take some time in case of power nets, but it will show you a short path between the points once it is done.

For more details see here: https://www.klayout.de/doc-qt5/manual/net_tracing.html#k_1

Matthias

dai

thanks you, @Matthias
it work for me

dai

Matthias

Very good

Thanks for letting me know. I hope the run time and the setup effort was acceptable.

Matthias

dai

yes,
run time is ok for me now, it is so good with non-commercial tool.
i run script on with GUI it work ok but when i change to run on command mode(no GUI) this mean i can not use trace(string tech,const Layout layout,const Cell cell,const Point start_point,unsigned int start_layer)
i have to change tech string to NetTracerTechnology. Do you have any way to create NetTracerTechnology from .lyt file?(like load function of Technology). I know i can read the xml file with my script to create the object but it is better if tool support this .

thanks @Matthias

dai

Matthias

Do you mean "klayout -b" with "no GUI" mode?

In this case, you should still be able to create and use a technology. Technology information is stored inside $KLAYOUT_HOME/tech/... (~/.klayout/tech/.. by default on Linux) and is read also when using "klayout -b ...". The net tracer stack configuration is stored inside the .lyt files in the "connectivity" section.

But how can you use the short detector if you do not have a UI? You need to point to a specific start and stop location.

Matthias

dai

Hi Matthias
Thank you for answering me.
Yes, i mean no GUI mode. You are right.
I found my issue now, because i have two .lyt files with same technology name( in subfolders in the tech folder), when Klayout turn on(with -b option) one of them was overwrite by another, when i try to change a .lyt tech but another lyt file still old and i didn't see any effect so i think tech was not loaded.
To resolved i just delete one so it work now

But how can you use the short detector if you do not have a UI? You need to point to a specific start and stop location.

=> i base on pins location. my purpose is just find short net for pins only.
thanks

dai