Unable to Directly Recompile Quartus II version 10.1 Design for UniPHY External Memory Interfaces in Quartus II version 11.0

Description

A design compiled in the Quartus II software version 10.1 cannot be directly recompiled in version 11.0, for speeds greater than 500 MHz.

Resolution

The workaround for this issue is to load the <variation_name>.v file generated by the version 10.1 MegaWizard Plug-In Manager into the version 11.0 MegaWizard Plug-In Manager and regenerate the IP core in version 11.0.