Internal Error: Sub-system: ATCL, File: /quartus/ccl/atcl/atcl_args.cpp, Line: 1080 - Internal Error: Sub-system: ATCL, File: /quartus/ccl/atcl/atcl_args.cpp, Line: 1080 Description Due to a problem in the Quartus® II software version 12.1 SP1 and earlier, you may see this error when running the following commands from the Quartus II Tcl Console for the PCI reference design: source pci_constraints_for_pci.tcl add_pci_constraints -speed 33 Resolution To work around this problem, run quartus_sh -s to run the Quartus II shell in interactive and use it to open the project and run the commands: project_open top_pci32.qpf source pci_constraints_for_t32.tcl add_pci_constraints -speed 33 This problem is scheduled to be fixed in a future release of the Quartus II software. Custom Fields values: ['novalue'] Troubleshooting novalue False ['PCI'] ['FPGA Dev Tools Quartus II Software'] novalue 12.1 ['Programmable Logic Devices'] ['novalue'] ['novalue'] ['novalue']