After placement, an estimated timing summary is output to the log file. By default, the number reflects the internal estimates of the placer. For example:
INFO: [Place 30-746] Post Placement Timing Summary WNS=0.022. For the most accurate timing information please run report_timing.
For greater accuracy at the expense of slightly longer run time, you can use the
-timing_summary option to force the placer to report the timing
summary based on the results from the static timing engine.
INFO: [Place 30-100] Post Placement Timing Summary | WNS=0.236 | TNS=0.000 |
- WNS = Worst Negative Slack
- TNS = Total Negative Slack