DVT VHDL IDE User Guide
Rev. 19.1.40, 13 November 2019
You can increase/decrease the font size in code editors using these buttons, on the main toolbar:
You can can also modify the font settings from Window > Preference > General > Appearance > Colors and Fonts. For global settings (used by all editors), select Basic > Text Font and for editor specific settings, select (e , Verilog, VHDL) Language > Editor > Text Font.