When -datapath_only option is not used, setting a Maximum Delay
constraint on a path, does not modify the minimum requirement on that path. The hold (or
removal) check on that path remains the default one.
Note: Using the
-datapath_only option with set_max_delay
results in the hold requirement being ignored on that/those path(s) (some internal
set_false_path -hold constraints are generated).Similarly, setting a Minimum Delay constraint on a path does not modify the default setup (or recovery) check.
If a path has only, for example, a max delay requirement, the path can be constrained
with a combination of set_max_delay and set_false_path
commands. See the following example:
set_max_delay 5 -from [get_pins FD1/C] -to [get_pins FD2/D] set_false_path -hold -from [get_pins FD1/C] -to [get_pins FD2/D]The above example sets a 5 ns setup requirement for the path starting on FD1/C and ending
on FD2/D. There is no minimum requirement due to the set_false_path
command.