Do Stratix V devices support a serial configuration device I/O voltage of 2.5V?

Description

No, Stratix® V devices using Active Serial (AS) configuration devices (EPCQ) do not support a configuration device I/O voltage of 2.5V. When using the AS configuration scheme you must use a configuration voltage of 3.0V.

Resolution

Currently in the Quartus® II software version 12.1 and earlier it allows you to select a "Configuration device I/O voltage" of 2.5V but this is a bug and is slated to be fixed in a future version of the Quartus II software.