Repeating phys_opt_design Design Changes - 2020.2 English - UG904

The design flow for repeating phys_opt_design design changes is shown in the following figure.

This flow differs from the retrofit flow in two aspects:

• The iphys_opt_design changes are incorporated after place_design instead of beforehand.
• Both placement changes as well as netlist changes are captured in the iphys_opt_design Tcl script.

Typically, you would use this flow to gain more control over the post-place phys_opt_design step. Custom "recipes" are created from combinations of replayed optimizations and new optimizations resulting in many possibilities for exploration of design closure.

The write_iphys_opt_tcl and read_iphys_opt_tcl commands have a -place option to replay the placement changes from phys_opt_design. This option should be used in this flow to repeat phys_opt_design steps after placement.