how to fix transition on excluded net?

Hi dota!

"reportIgnoredNets" can be used to query which nets aren't being operated on by timing optimization.  If you could try this command and find out more specifics on the nature of the net with design rule violations remaining please do post back and we could offer some suggestions for how to get the tool to fix them.

Hope this helps,
Bob

reportIgnoredNets report only special net is ignored. optDesign exclude nets include special net and clock net.

which command can report all clock net? or write a script by myself to capture these nets.

You may ask why clock net has transition violation after CTS. I think the root point of clock created in sdc is not alway same as the begin point of clock tree defined in *.ctstch file. so some nets may contain clock attribute without  be considered in CTS.

If it haapen, how to deal with it.

thanks

Dota

Thanks for the follow-up.

As you work with these clock nets, it would be good to understand whether the nets in question clock nets from a timing perspective -or- from a CTS perspective.  The following blog post might be informative in this area:

http://www.cadence.com/Community/blogs/di/archive/2008/08/20/understanding-clock-net-markings-in-soc-encounter.aspx?postID=10803

There is a native command that is targeted at fixing the CTS clock nets that have DRVs remaining because they've been excluded (which happens most typically because of an ExcludePin statement in the clock tree spec file): "fixClockExcludedNetDRV".  I'm not sure whether it would be helpful in your case- it depends on why your nets are being excluded.

It seems like reportIgnoredNets should report clock nets as being ignored.  I just tried a small testcase and I see some clock nets being caught:

56 IO nets
6 clock nets
179 special nets
1 no-driver net 

There might be a bug in reportIgnoredNets in your case- though it is hard to tell for certain without looking at the data.  If you feel there is a bug, I'd encourage you to follow-up with your local support AE or by filing a service request on http://sourcelink.cadence.com.

Great discussion!  Thanks for taking the time.

Regards,
Bob