This Internal Error may be seen in the Quartus® II software version 9.1 for designs targeting Stratix® II, Stratix II GX and Arria® GX devices which contain auto-generated DCFIFO MegaFunctions.
Patch 0.51 is available for the Quartus II software version 9.1 to fix this problem. Download and install patch 0.51 for the Quartus II software version 9.1 from the aproppriate link below:
Windows:
- Quartus II software version 9.1 patch 0.51 for PC (.exe file)
- Quartus II software version 9.1 patch 0.51 for PC readme.txt file
Linux:
- Quartus II software version 9.1 patch 0.51 for Linux (.tar file)
- Quartus II software version 9.1 patch 0.51 for Linux readme.txt file
This problem is scheduled to be fixed in a future release of the Quartus II software.