Sometimes it is advantageous to iterate through a command multiple times
to obtain the best results. For example, it might be helpful to first run phys_opt_design
with the force_replication_on_nets
option to optimize some critical nets that
appear to have an impact on WNS during route.
Next, run phys_opt_design
with any of the
directives to improve the overall WNS of the design.
In Non-Project Mode, use the following commands:
phys_opt_design -force_replication_on_nets [get_nets -hier *phy_reset*]
phys_opt_design -directive <directive name>
In Project Mode, the same results can be achieved by running the first
phys_opt_design
command as part of a Tcl-pre script
for a phys_opt_design
run step which will run using the
-directive
option.