What's the difference between TNS and WNS?

[vreddy]

wat excatly the TNS ( total negative slack)?? & WNS ( worst negative slack)......??
wats the difference bet them??
wat happens if either of it is -ve ??

thanks

 

[leeguoxian]

wns tns

wat excatly the TNS ( total negative slack)?? & WNS ( worst negative slack)......??

I think u already have answers .
I saw WNS&TNS in Astro timing report.
If there are setup violations, WNS is the worst one of all negative slacks.
And TNS is the sum of all negative slacks.
I'm not sure about my answer.

 

[asicengineer1]

total negative slack

hi, my guess is, TNS is sum of all negative slacks, whereas WNS is slack of the the critical path.

correct me if i'm wrong.

 

[p_shinde]

wns negative slack

yes y ppl r rgt
TNS: total number of negative slack (violated ) paths
WNS: worst path ...path having max. slack

 

[kalli]

worst neg slack

Worst Negative Path(WNS) points to the path having the maximum negative slack.
Total Negative Slack(TNS) gives the sum of all the negative slacks in the design.

From the value of TNS, we can know the severity of the slack in total design and whether to proceed or not with the current design model.

WNS slack can be negative or zero or positve.
It it is +ve, it means that there are no violations and it is giving the least of the positive slack. In this casee, TNS will be zero.

TNS can be either -ve or zero.