## Simulation ```{warning} Outdated Documentation! This documentation version is out of date. Please check the [latest version 2026.1](https://hog.readthedocs.io/en/latest/). ``` Hog supports all simulation software currently supported by Vivado (click [here](https://www.xilinx.com/products/design-tools/vivado/simulation.html) for the full list). Hog simulation has been tested with Vivado Simulator (also called Xsim), Mentor Graphics Questasim, Mentor Graphics Modelsim and Aldec Riviera Pro. The simulation setup is always handled by Vivado, as if the simulation button on the GUI was clicked, then the simulation run is done with the simulation software. ```{note} Currently the simulation is not supported under Quartus. A complete support will be included in the next releases. ``` ### Simulation sets Simulations are organised in so-called "simulation sets" as in Vivado. ![simulation sets](figures/simulation_sets.png) In this figure, you can see an example of simulation sets, these are contained in Vivado in the `Simulation_Sources` folder in the hierarchy view. You can right click on each of them, set it as active (becomes bold) and run it by clicking the "Run simulation button". In the figure above `algo_sim` is the active simulation. Every simulation set has a top entity, the test bench containing the device under test, and can be simulated independently. Hog creates a simulation set for each `.sim` [list file](02-List-files.md) in the Top project folder (`Top/myproj/list`). It is also possible to have multiple simulation libraries in the same simulation file sets. To do so, you should assign the `lib=library_name` property to the included file or sim list file in the `.sim` list file in the Top simulation folder. For example, if you have a simulation list file called `mysim` in your Top project folder with the following content, ``` src/top_sim.vhd src/lib1/lib1_sim.vhd lib=lib1 src/lib2/lib2.sim lib=lib2 ``` this will create a simulation file set `mysim` in Vivado with three libraries: `mysim`, `lib1` and `lib2`. ```{note} Vivado creates by default a simulation fileset called `sim_1`. To use it in Hog, simply creates a list file called `sim_1.sim` in your `list` folder. ``` ### Simulation Configuration File The simulation properties are read from another file called `./Top//sim.conf`, with a similar syntax as the `hog.conf`. The need for a separate file lies on the fact that touching the simulation properties does not affect the actual firmware which will be synthesised. Thus we don't want Hog to change the version of the project, when the developers touch only the simulation. Simulation properties can be set individually for each simulation set, or globally for all of them. For example, to set `xsim.elaborate.rangecheck` property for the simulation set `sim_1`, you should write ```ini [sim_1] xsim.elaborate.rangecheck = true ``` Alternatively, if you want to set this property for all your simulation sets, you should write. ```ini [sim] xsim.elaborate.rangecheck = true ``` A typical `sim.conf` file would look like then: ```ini [sim] XSIM.ELABORATE.RANGECHECK = False [my_sim] ACTIVE=1 MODELSIM.COMPILE.VHDL_SYNTAX=2008 MODELSIM.CUSTOM_UDO=file1.do MODELSIM.SIMULATE.CUSTOM_UDO=file1.do MODELSIM.SIMULATE.CUSTOM_WAVE_DO=file1.tcl MODELSIM.SIMULATE.RUNTIME=500us TOP=tb_my_sim ``` Please note that the for the settings that require the name of a file, for instance `CUSTOM_UDO` or `CUSTOM_WAVE_DO`, only the file name must be set, and not the full path. Remember also to include these files in your `.sim` list file, in order to add them to the Vivado project. Hog also offers the possibility to generate the `sim.conf` automatically, by clicking on the [Hog Conf Button](02a-Hog-Buttons.md) in the Vivado GUI. Remember that individual simset properties have always the priority with respect to the global. So you can set a global property for all your simsets, and change it just for one of them, for example. To set a particular simset as the active one, you need to set the `ACTIVE` property to `1` in your `sim.conf`, under the relative simset section. If no active simset is specified, Hog will set as active the last created simulation set. ```{note} In Hog versions older than `Hog2022.2`, only a limited set of simulation properties could be specified. These properties were directly set inside the `.sim` files and were: - `topsim=`: (mandatory) the name of the entity that will be the top level of the simulation; - `runtime=