Getting timing path using the GUI

[xobs]

I saw your presentation at Latchup, and was really impressed with how you were able to dive into the design and figure out things such as the critical path from the GUI.

I'm using the OpenLane flow, and have the odb file open:

However, it is not clear how to get timing information to show up. I am viewing the newest and largest odb file from openlane/mimi-bare/runs/mimi-bare/tmp so I assume it's the file with all of the relevant data.

Is there some setting I need to change in openlane in order to find the relevant data? Or is there another flow I should be using?

[maliberty]

You need to hit the update button. It takes a while so we don't do it automatically in case you want to do any setting first.

[xobs]

For some reason, in this design the update happens instantly in both the Timing Report and the Clock Tree Viewer, but both windows remain empty.

[QuantamHD]

Yeah so an odb file isn't enough to actually get the timing report. You need to read in the liberty files and sdc file after running read_db.

[xobs]

Thanks, the sdc was the missing piece.

With this script, I get clock support in openroad:

read_db routing/16-global.odb
read_liberty /si/conda/share/pdk/gf180mcuC/libs.ref/gf180mcu_fd_sc_mcu7t5v0/liberty/gf180mcu_fd_sc_mcu7t5v0__tt_025C_5v00.lib
read_sdc 12-minimax.sdc

[maliberty]

You may also need to load parasitics (eg spef) to get accurate timing at the end of the flow. If you are at global routing you may want to run estimate_parasitics -global_routing

[xobs]

Thanks for all of the help -- this is an amazing superpower