Error (21075): The core supply voltage value of '0.9V' is illegal for the currently selected part.

Description

You may see this error when you migrate an existing design targeting a Stratix® V device to the Quartus® II software version 12.0. The error message may be issued for values of '0.9V' or '0.85V'.

This error occurs because the Stratix V device family does not support the assignment NOMINAL_CORE_SUPPLY_VOLTAGE beginning with the Quartus II software version 12.0.

Resolution

To avoid this error, edit the Quartus II Settings File (.qsf) for your project and delete the following assignment:

set_global_assignment -name NOMINAL_CORE_SUPPLY_VOLTAGE <0.85 or 0.9V>

Save the .qsf and recompile your project.