Tracing X

Hi Dan.

Have you tried the "goto cause" analysis option in SimVision?

You do need to have elaborated your design with "-access +rc" to enalbe the connectivity tracing (that's the +c bit).
Then in the waveform window you can put the cursor on a value you want to trace (doesn't have to be an X).
Next, right click on the signal's name and select "go to cause" from the pop-up menu.

This should then open the source browser, pointing a the line that caused the transistion to the value you're interested in.

You can repeat this to trace back  as far as you wish; the time cursor automatically jumps forward in time to the transition, so all you have to do is keep "going to cause".

Hope this helps.

Steve.

Hi Steve,

Thanks for the suggestion! Two points...

Firstly after my inital post I saw I can right click the signal name in Simvision and use "Trace drivers in sidebar". This can also trace X's. This sounded perfect, but when I try it for a gate level sim, Simvision 9.2 (also tried number of Incisive 8.x versions) merely hang?And this is on a beefy machine with 32gb of ram. To be honest I'm getting all sorts of odd behaviour in Simvision when running this gate level sim.

Secondly regarding your suggestion, which also sounds very useful, the "go to cause" is greyed out, despite the fact the sim has been launched with +access+rwc . (I'm running this in post-processing mode rather than interactive). Any thoughts on why this might be?

Many thanks

Hi Mickey,

Thanks for replying.

I'm not explicitly loading the snapshot when launching simvision, I merely load the .trn file. However when I ask Simvision to trace a signal, simvision frequently asks for a cds.lib and a snapshot, though also on occasions it doesn't ask for this information and carries attempts to carry out the tracing.