Why does VCS simulation fail when using Nios® V processor? - Why does VCS simulation fail when using Nios® V processor? Description This problem might be seen in the Intel® Quartus® Prime Pro Edition Software version 21.3 till 23.1 when running simulation on Nios® V processor system using the Synopsys* VCS simulator. The simulation reports the following error message during compilation: Error-[IND] Identifier not declared …any HDL files… Identifier ‘NONE’ has not been declared yet. If this error is not expected, please check if you have set `default_nettype to none. This is due to the code line “` default_nettype none ” in the processor's RTL. Resolution Navigate to the following folder: <project directory>\simulation\ip_components\ nios_system_intel_niosv_<variant>_<device>\intel_niosv_m_unit_2141\ sim\synopsys\reg_file.sv Search for “ `default_nettype none ”. Comment the single code line. Rerun the VCS simulator. This problem is currently scheduled to be resolved in a future release of the Intel® Quartus® Prime Pro Edition Software. Custom Fields values: ['novalue'] Troubleshooting https://hsdes.intel.com/appstore/article/#/22016409968 False ['novalue'] ['FPGA Dev Tools Quartus® Prime Software'] novalue 22.4 ['Agilex™ FPGA Portfolio', 'Arria® 10 FPGAs and SoCs', 'Cyclone® 10 FPGAs', 'Stratix® 10 FPGAs and SoCs'] ['novalue'] ['novalue'] ['novalue']