report_timing -from [all_inputs] -nworst 1000 -sort_by group \
report_timing -to [all_outputs] -nworst 1000 -sort_by group \
Improper I/O delay constraints can lead to impossible timing closure. The implementation tools are timing driven and work on optimizing the placement and routing to meet timing. If the I/O path requirements cannot be met and I/O paths have the worst violations in the design, the overall design QoR will be impacted.