Preventing Design Compiler optimization to stop at the first violation

[vikasvij1982]

Hi,

I have a design which deals with 100's of paths on which i set min/max delays and i would like to know if Design Compiler has any command which actually only gives me the violators out of all these paths. e.g. Suppose say i have path 1, and 2. I individually synthesize path1 and it works. Suppose path2 is added in the list of constraints and path2 optimization happens before path1. If path2 constraints are not met then design compiler exits optimization and since path1 has not been optimized, i get a negative slack for path1 also even though it should not report a negative slack. Hence if i have 100 paths then it is not possible for me to check and optimize each path individually first and then combined. Hence if there was a method which did not stop design compiler when path2 got violated and optimized path1 also then it will be helpful.

Thanks

Vikas

 

[dianin]

You can define the different group paths (command group_path) for those and give the higher values for crictical_range , higher the value of critical_range , the more optimization will be performed by tool. Most of the time it works but you have to check what is the best value for critical range , it will also impact the runtime.