Why do I get the error "SDF files require Altera primitive library" when I try to load my design in ModelSim? - Why do I get the error "SDF files require Altera primitive library" when I try to load my design in ModelSim? Description You get this message if you compile your < project name > .v file and apply the < project name > .sdo file without compiling the < project name > .vo netlist in your design. The < project name > .v file used for compilation in the Quartus ® II or MAX PLUS ® II software is the register transfer level (RTL) code. The < project name > .vo file is the netlist created by the software. The < project name > .sdo file requires that the < project name > .vo netlist is compiled in the project because the < project name > .vo file instantiates the primitives needed for the timing simulation. Custom Fields values: ['novalue'] Troubleshooting novalue False ['novalue'] ['novalue'] novalue novalue ['Programmable Logic Devices'] ['novalue'] ['novalue'] ['novalue']