Internal Error: Sub-system: HDB, File: /quartus/db/hdb/hdb_inst_name.cpp, Line: 3421 - Internal Error: Sub-system: HDB, File: /quartus/db/hdb/hdb_inst_name.cpp, Line: 3421 Description Due to a problem in the Quartus® II software version 13.0, you may see this internal error when compiling designs targeting Arria® V devices and containing a DDR3 interface. Resolution To work around this issue, edit your Quartus® II Settings File (.qsf) and comment out all assignments of the form: set_global_assignment -name ASSIGNMENT_GROUP_MEMBER ... This problem was fixed in Intel® Quartus® software version 13.1 Custom Fields values: ['novalue'] Troubleshooting 1408029572 False ['novalue'] ['FPGA Dev Tools Quartus II Software'] 13.1 13.0 ['Arria® V GT FPGA', 'Arria® V GX FPGA', 'Arria® V GZ FPGA', 'Arria® V ST FPGA', 'Arria® V SX FPGA'] ['novalue'] ['novalue'] ['novalue']