physical optimization psynopt

You can run incremental placement-based optimization that supports area recovery, design rule fixing, sizing, and route-based optimization by using the psynopt command. By default, this cmd performs timing optimization and design rule fixing, based on the maximum capacitance and maximum transition settings while keeping the clock networks untouched.

It can also perform power optimizations if you specify power constraints. The psynopt command continues to optimize until no more optimizations can be performed. When done, it completes the optimizations with a legalized placement of the design.

This process can remove dangling cells (cells that do not drive other cells), resulting in a reduced number of cells in the design. If you need to prevent the removal of such cells, do one of the following:

-  To prevent the removal of specific cells, use the set_dont_touch cmd to apply a dont_touch           attribute on each of those cells.

 -  To retain the unloaded cells globally, set the physopt_delete_unloaded_cells variable to false.

To perform placement optimization with the psynopt cmd, enter

icc_shell> psynopt  [optional]