DVT SystemVerilog IDE User Guide
Rev. 21.1.44, 19 October 2021

27.8 WaveDrom Timing Diagrams

WaveDrom is a tool that draws timing diagrams (waveforms) from a simple textual description written in JSON. DVT renders WaveDrom waveforms in the Inspect View. The waveform diagram is updated on the fly (as you type).

The waveform description can be:

  • either embedded in comments, surrounded by @WAVEDROM_START...@WAVEDROM_END pragmas

  • or in files with *.json or *.json5 extensions

When the waveform description is found in a file with a valid extension, the Inspect View will process it's content and render the diagram when opened. The waveform description file can also be embedded in comments using the @WAVEDROM_FILE pragma, followed by its location. The location of the file will be solved relatively to the current editor.

To save the diagram as an SVG file, right-click on it in the Inspect View.

DVT offers the ability to view WaveDrom diagrams through tooltips, by hovering over any waveform written inside DVT editors.

Tip: The WaveDrom documentation is available here.

Note: To specify additional file extensions, use the +dvt_wavedrom_file_ext_add+<extension> build config directive. To clear the extensions list use +dvt_wavedrom_file_ext_clear.

Note: To specify additional search file locations to use in junction with @WAVEDROM_FILE pragma, use the +dvt_wavedrom_files_location_add+<location> build config directive. To clear the extensions list use +dvt_wavedrom_files_location_clear.

Note: By default, only waveform descriptions of maximum 5000 characters are rendered. You can change this threshold from menu Window > Preferences then DVT > Editors.

Note: DVT uses WaveDrom version 2.6.8.