Description
Due to a problem in the Quartus® II software versions 12.1 and earlier, you may receive this error message when using the HiSpi I/O standard with differential on-chip termination (OCT). This problem affects designs targeting Cyclone® V devices.
Resolution
To work around this problem use the LVDS I/O standard.
This problem is fixed beginning with the Quartus II software version 12.1 SP1.