Internal Error: Sub-system: CUT, File: /quartus/db/cut/cut_stratixv_lc_pll_group.cpp, Line: 132 altera_xcvr_low_latency_phy - Internal Error: Sub-system: CUT, File: /quartus/db/cut/cut_stratixv_lc_pll_group.cpp, Line: 132 altera_xcvr_low_latency_phy Description You may see the following Quartus® II Fitter error if you make a PLL_TYPE ATX assignment to the top level of a Stratix® V GX Low Latency PHY configured with an "FPGA fabric transceiver interface width" of 40 or 66, using Quartus® II Software Versions 11.0SP1 and earlier. Internal Error: Sub-system: CUT, File: /quartus/db/cut/cut_stratixv_lc_pll_group.cpp, Line: 132 altera_xcvr_low_latency_phy For the configuration above, the Low Latency PHY will instantiate a Gearbox and fPLL. The ATX PLL_TYPE assignment will conflict with the fPLL insantiated inside the PHY and cause an error. To work around this issue, you can either: Assign the PLL_TYPE ATX assignment to the tx_pll only. Or Upgrade to Quartus II Software Version 11.1 which has a Tx PLL drop down option. In this case you must remove the PLL_TYPE ATX assignment. Custom Fields values: ['novalue'] Troubleshooting novalue False ['novalue'] ['novalue'] novalue novalue ['Stratix® V FPGAs', 'Stratix® V GS FPGA', 'Stratix® V GX FPGA'] ['novalue'] ['novalue'] ['novalue']