Tutorial: DSim Desktop for GOWIN

Contents

1. Introduction
2. Prerequisites
3. Example design
4. Open a project
5. Create a project
6. Add files to your project
7. Add a Simulation Configuration
8. Compile your design
9. Run your design
10. View the waveform
11. Debug your design
12. Run your design in the cloud
13. Next Steps

Introduction

DSim Desktop is a versatile Visual Studio Code (VSC) extension, offering unparalleled flexibility in HDL simulation, supporting both cloud-based and local (on-prem) workflows. This article describes how to use DSim Desktop to simulate the GOWIN Reference Design "I2C_Master".

NOTE: The screenshots in this article may not exactly match what you see on your computer. The functionality and performance of DSim Desktop remain the same.

Prerequisites

1. Install DSim Desktop.
2. Tour of DSim Desktop.

Example design

For this tutorial, use the Gowin_I2C_Master_refDesign example design. If you haven't already done so,

1. Download Gowin_I2C_Master_refDesign.

2. Extract the zip file into the folder Gowin_I2C_Master_RefDesign with read/write access.

3. Click the VSC Explorer and navigate to the folder /Gowin_I2C_Master_RefDesign. If the folder is not visible in the VSC Explorer, open it by clicking Open Folder from the File menu.

If you want to simply compile and simulate this example design, proceed to Open a project.

If you want to create the project from scratch, proceed to Create a project.

Open a project

To open an existing project, simply right-click the project's .dpf file from the VSC Explorer and select DSim Desktop: Open Project.

For this tutorial, navigate to the folder /simulation/metrics, right-click i2c_master_tutorial.dpf and select DSim Desktop: Open Project.

Then skip to the step Compile your design.

Create a project

Simulating designs in DSim Desktop is project-based, so the first thing you need to do is create a project.

1. Navigate to the folder /simulation, right-click the folder /metrics and select DSim Desktop: New Project.

2. Enter i2c_master for the Project File Name and click Save.

Add files to your project

As with any simulator, you need to know all the source files and their dependent files that need to be compiled, as well as what libraries they are compiled into. It is highly recommended that you use file lists to compile files of the same language and options.

Example steps

1. Navigate to /simulation/metrics, right-click tutorial_filelist.txt and select DSim Desktop: Configure File.

2. This is a file list of Verilog files to be compiled into the default library work, so select Verilog / SystemVerilog from Choose a Language, and tick the box Configure as file list. Click Save.

3. Navigate to /tb, right-click i2c_tb.v and select DSim Desktop: Configure File.

4. This is a SystemVerilog file to be compiled into the default library work, so the defaults are correct. Click Save.

5. Click the DSim Desktop view and expand the libraries in the LIBRARY CONFIGURATION.

The file list and file appear in their respective libraries. Note that there are different icons for file lists and files. The ? beside the libraries and files indicate that their Compilation Status is Unknown, ie. they have not been compiled yet.

Add a Simulation Configuration

Once you've finished adding all of your files to your project, you can add a Simulation Configuration. This enables you to elaborate and run different simulations on the same set of compiled libraries. Add a new Simulation Configuration:

1. Hover over the SIMULATION CONFIGURATION drop-down menu and click the + button.

2. Enter the following in the Configure Simulation tab:

• Sim 1 for the Simulation Name.
• -top work.i2c_tb -timescale 1ns/1ns +acc+b -waves waves.mxd -wave-scope-specs wave.list for the Options. These are the DSim options executed when you hit the 'Run' button. In our example, this elaborates and runs the testbench as the top-level module and generates a waveform file during runtime as specified by the Options:

-top work.i2c_tb: top-level module is i2c_tb found in the compiled library work

-timescale 1ns/1ns: set the default timescale to 1ns/1ns

+acc+b: generate support for waveform dump

-waves waves.mxd: enable wave dump to waves.mxd

-wave-scope-specs wave.list: specify that the detailed scopes to dump are in the file wave.list

Click Save.

For common DSim options, see the DSim column under the Standard Options section of DSim Common Options.

Compile your design

1. Click the 'Compile Project' play button under the LIBRARY CONFIGURATION to compile your project.

All of the executed DSim simulator commands and their resulting output are displayed in the OUTPUT window. A notification pops up indicating the overall result of the compile. The ? beside the libraries in the LIBRARY CONFIGURATION turn into check marks after the successful compilation of the library.

Optionally, click the 'Turn Auto Scrolling On' button (lock icon) in the OUTPUT window to have the output scroll automatically.

Run your design

After the successful compilation of your design, you can run it locally (on-prem) by simply clicking the 'Run' button beside Sim 1 in the SIMULATION CONFIGURATION.

All of the executed DSim simulator commands and their resulting output are displayed in the OUTPUT window. A notification pops up indicating the overall result of the run. A check mark appears beside Sim 1 in the SIMULATION CONFIGURATION after a completed simulation run.

View the waveform

1. Click the VSC Explorer and double-click on /simulation/metrics/waves.mxd.

2. Use the integrated waveform viewer like you would any other waveform viewer. See User Guide: Metrics Waveform Viewer for details.

3. Close the waves.mxd tab when you're done. Subsequent simulations will overwrite this waveform file unless you change its name in the Simulation Configuration Options dialog box.

Debug your design

1. Using a combination of the waveform waves.mxd, the compilation log dvlcom.log, and the simulation log dsim.log, debug your design.

2. Make any necessary changes to your HDL and testbench files in the VSC Explorer and save them.

3. Close all the tabs in the Editor pane.

4. You only need to re-compile the files or libraries that have changed. For example, if you only changed the testbench file, click the 'Compile File' play button next to i2c_tb.v in the LIBRARY CONFIGURATION of the DSim Desktop view.

5. After the successful re-compilation of your design, you can re-run it by simply clicking the 'Run' button beside Sim 1 in the SIMULATION CONFIGURATION.

Run your design in the cloud

1. When you're ready to run your simulation in the cloud, click the 'Run in DSim Cloud' button next to the desired Simulation Configuration.

2. DSim Desktop automatically converts your local simulation to a job file and submits it to the cloud. You must be signed into your DSim Cloud account to submit a job to the cloud. A notification pops up indicating the status of your job submission. When it is complete, click the 'Show Jobs' button or in your DSim Desktop view, expand the JOBS section to see your job.

3. Expand your job to see the status of each task. Sometimes it may take a while (several minutes) for remote cloud resources to become available to run your job.

4. Once your job is complete, click the 'Download All Artifacts' button to retrieve your simulation artifacts.

5. A notification pops up indicating the status of your artifact download. When it is complete, click the 'Reveal in Explorer' button or in your VSC Explorer view, navigate to /simulation/metrics/_downloaded_artifacts/i2c-master-xxxxx/work.

6. Your VSC Explorer will open to the folder where your simulation artifacts were downloaded from your simulation in the cloud.

Next Steps

1. Play around with the DSim Desktop GUI. Right-click on the files in the VSC Explorer to see what options are available. The DSim Desktop options are prefixed with DSim Desktop:. Right-click on the files in the LIBRARY CONFIGURATION and SIMULATION CONFIGURATION to see what options are available.

2. Create your own projects for the Gowin_I2C_Master_refDesign design:

• Add the files from tutorial_filelist.txt to your project as individual files.

3. Create and simulate your own designs.