Hi Mohan,Originally posted in cdnusers.org by EngHan
Thanks for the tip. But I think you miss my point.
The main concern is how to add stack via on top of the pins of the spare gate (and not placing the spare gate).
I believe that SOC does not have direct command to add stack via on the pins. I can write some code to do this, but I wish to know how other people do this (I have learnt this requirement several years ago, but I personally is doing this the first time) before I spend time in the coding.
However, I understand that with this requirement, there are added restriction to the placement flow. Firstly, I think the option "setPrerouteAsObs" is too restrictive as it also prevent non-spare-gate to be keep out of power stripes, result is huge loss in untilizaiton. Secondly, the stack via can only be added after placement (infact after cts, and possibility just before detailed route), the global router don't see this and cannot optimise the congestion with these stack via. I hope there is some smarter way to implement the flow.