In STA say in PT we use Back-annotated SDF where in in P & R Tool we extract the SDF once detail route is completed. So.. analysing the RC Delay and process variation effects are more accurate in PT as compared to Astro or Blast Fusion etc.. Hope this helps.....
1.What is timing model and what is original.Why P&R tool not using timing models? If we use timing models in P&R tools,then we need not do sign-off ? am I right.
2.We are using same libraries,then how can we say RC delay values and process variation effects more accurate in PT as we compare to P&R tool and why?