Description
Due to a problem with the 32-bit Windows installation files for the Quartus® II software version 12.0 SP2 and earlier, you may observe functional errors on Arria® V devices ALTLVDS_TX interfaces.
The incorrect functionality observed is that certain LVDS pairs will transmit a "101010..." pattern at the same rate as the LVDS SERDES (fast) clock.
This issue does not apply when running the Quartus® II software on Linux.
Resolution
To workaround this issue, you should use the 64-bit version of the Quartus® II software.
This problem is fixed in version 12.1sp1 of the Quartus® II software.