13.25.15.3.1 Automatic Demotion/Promotion

Demote global nets whose fanout is less than: Enables the global clock demotion of global nets to regular nets. By default, this option is OFF. The maximum fanout of a demoted net is 12.
Note: A global net is not automatically demoted (assuming the option is selected) if the resulting fanout of the demoted net is greater than the max fanout value. Actel recommends that the automatic global demotion only act on small fanout nets. Actel recommends that you drive high fanout nets with a clock network in the design to improve timing and routability.
Promote regular nets whose fanout is greater than: Enables global clock promotion of nets to global clock network. By default, this option is OFF. The minimum fanout of a promoted net is 200.

But do not promote more than: Defines the maximum number of nets to be automatically promoted to global. The default value is 0. This is not the total number as nets need to satisfy the minimum fanout constraint to be promoted. The promote_globals_max_limit value does not include globals that may have come from either the netlist or PDC file (quadrant clock assignment or global promotion).

Note:
  1. Demotion of globals through PDC or Compile is done before automatic global promotion is done
  2. You may exceed the number of globals present in the device if you have nets already assigned to globals or quadrants from the netlist or by using a PDC file. The automatic global promotion adds globals on what already exists in the design.