ID:21163 The Spread Spectrum Clocking (SSC) feature is no longer supported in Cyclone IV GX EP4CGX75, EP4CGX50 and EP4CGX30CF23 devices.

CAUSE: You attempted to enable the Spread Spectrum Clocking (SSC) feature in Cyclone IV GX EP4CGX75, EP4CGX50 and EP4CGX30CF23 devices.

ACTION: Re-instantiate the ALTGX instances.