Toplevel Simulation Control Signal And Retain Post-Fit Netlist

Quartus will not assign virtual pins to any physical pin, as that would defeat the purpose of being virtual.

Say you have this pin 'TestVirtualPin' declared as virtual. If you simulate you design, in Modelsim or using the Quartus internal simulator, you will have to drive this pin or the simulation will complain about the 'X' value.

The only thing yet to find out is how a design with virtual pins will function in real hardware.

What I just did.

And the result is that a virtual pin is always read as '0' in a 'real' device, even if you initialise it to '1' as:

library altera ;
use altera.altera_syn_attributes.all ;
entity top is
 ...
 port (
  ...
  TestVirtualPin : in std_logic := '1' ;
  ...
  ) ;
  attribute altera_attribute of TestVirtualPin  : signal is "-name VIRTUAL_PIN on";
end entity

it will be read as '0'.