Path segmentation is introduced when specifying invalid startpoint or endpoint for the -from or -to options of the set_max_delay and set_min_delay commands only. When a set_max_delay introduces path segmentation on a path, the default hold analysis no longer takes place. You must constrain the same path with set_min_delay if you desire to constrain the hold analysis as well. The same rule applies with the set_min_delay command relative to the setup analysis.
Path segmentation must only be used by experts as it alters the fundamentals of timing analysis:
- Path segmentation breaks clock skew computation on the segmented path.
- Path segmentation can break more paths than the one constrained by the segmenting
set_max_delayorset_min_delaycommand.