10.3.2.2. Simulation Considerations
The simulation features were created for easy simulation of Nios® V processor systems when using the simulator. The documentation for the processor documents the suggested usage of these features. Other usages may be possible but will require additional user effort to create a custom simulation process.
The simulation model is implemented in the UART core's top-level HDL file; the synthesizable HDL and the simulation HDL are implemented in the same file. The simulation features are implemented using translate on and translate off synthesis directives that make certain sections of HDL code visible only to the synthesis tool.
Do not edit the simulation directives if you are using Altera's recommended simulation procedures. If you do change the simulation directives for your custom simulation flow, be aware that Qsys overwrites existing files during system generation. Take precautions so that your changes are not overwritten.