Due to a problem in the Quartus® II software version 11.1 SP2 and earlier, the MegaWizard™ Plug-In Manager may generate an incorrect file if you convert a Stratix® IV memory to a Stratix V memory. If your Stratix IV memory specified Old Data for mixed-port read-during-write behavior, the MegaWizard Plug-In Manager generates the Stratix V memory with the same option even though it is not supported in Stratix V devices. In Stratix V memory, only New Data is supported for mixed-port read-during-write behavior. The Quartus II software generates an error when compiling this memory with the unsupported option.
To work around this problem, select the New Data option for mixed-port read-during-write behavior when regenerating Stratix IV memories for Stratix V devices.
This problem is fixed beginning with the Quartus II software version 12.0.