estimate_parasitics -global_routing on a post-global_route design loaded via read_db

[nayiri-k]

Is it possible to run estimate_parasitics -global_routing on a post-global_route design that's been loaded via the read_db command? As in, global_route has been run on the design before it was saved with write_db, but global_route has not been run in this current OpenROAD session. I keep getting this error:

>>> read_db post_global_route
>>> estimate_parasitics -global_routing
[ERROR RSZ-0005] Run global_route before estimating parasitics for global routing.

[maliberty]

@eder-matheus I thought this was possible. Please comment

[eder-matheus]

Yes, it is possible. As long as you have the guides in the database, global route should be able to load them to its internal structures when calling estimate_parasitics.
@nayiri-k A testcase with the failure would be good, if possible.

[eder-matheus]

@nayiri-k You can also try to read the guides file before running estimate_parasitics, if you have written it in the global route run.

[nayiri-k]

The read_guides command fixed it, I wasn't aware of it before. Thanks!

[maliberty]

Are you using a very old version of OR for this? The guides should be saved in the db.

[nayiri-k]

Yes you're right my version was a few months old, new version doesn't need the read_guides command.

[maliberty]

OR improves a lot over time so it is a good practice to test with a current version when you find a problem.