1. Why Customize Vim?
By default, Vim works fine — but customizing it can boost your editing speed, accuracy, and comfort dramatically.
With just a few lines in your .vimrc or .exrc file, you can:
- Enable syntax highlighting for Verilog, SystemVerilog, Tcl, and C
- Auto-indent your code neatly
- Adjust tab spacing
- Make searches case-insensitive
- Display line numbers for easy debugging
These features are especially valuable when editing large RTL, constraint, or testbench files in Linux.
2. What Are .vimrc and .exrc Files?
| File | Description | Location |
| .vimrc | Vim configuration file | Stored in your home directory (~/.vimrc) |
| .exrc | Vi configuration file (for older systems) | Also in home directory (~/.exrc) |
💡 Note:
- In Linux, Vim uses .vimrc.
- On minimal setups (like embedded or older servers), Vi may use .exrc.
3. Sample .vimrc for VLSI Engineers
Here’s a clean, optimized configuration that works perfectly for Verilog/SystemVerilog, Tcl, and scripting:
” ===============================
” VLSI Engineer Vim Configuration
” ===============================
set nocompatible ” Use modern Vim behavior
syntax on ” Enable syntax highlighting
set nu ” Show line numbers
set ai ” Auto-indent new lines
set si ” Smart indent
set ts=4 ” Set tab spacing to 4 spaces
set sw=4 ” Set shift width to 4
set expandtab ” Convert tabs to spaces
set ic ” Case-insensitive search
set hlsearch ” Highlight search results
set showmatch ” Highlight matching brackets
set nobackup ” Prevent backup files (~)
set nowrap ” Don’t wrap long lines
set cursorline ” Highlight current line
set background=dark ” Better for terminal readability
filetype plugin indent on ” Enable filetype-specific indentation
💡 Usage:
- Create or open .vimrc:
vi ~/.vimrc
- Paste the above configuration
- Save and quit using :wq
4. Sample .exrc for Classic Vi Users
If your system doesn’t support .vimrc, use .exrc instead:
set nu
set ai
set showmatch
set beautify
set tabstop=5
set ignorecase
This provides a lightweight setup for minimal systems — useful on remote EDA servers where Vim might not be fully installed.
⚡
5. Useful Commands for Managing Configurations
| Command | Description |
| :scriptnames | Lists all scripts and configs loaded by Vim |
| :echo $MYVIMRC | Shows location of your .vimrc file |
| :e $MYVIMRC | Opens .vimrc directly for editing |
| :source ~/.vimrc | Reloads .vimrc after changes |
| :set | Shows all modified options |
Example:
:e $MYVIMRC
Directly opens your config file — no need to browse folders.
6. Extra Productivity Options
| Option | Description |
| set ruler | Shows line and column number in status bar |
| set incsearch | Show live matches while typing search |
| set scrolloff=3 | Keeps 3 lines visible when scrolling |
| set laststatus=2 | Always show status line |
| set title | Display current filename in terminal title bar |
| set undofile | Enable persistent undo (Vim 8+) |
These improve navigation when editing long code files or scrolling through synthesis logs.
7. Syntax Highlighting for Verilog & SystemVerilog
You can enable syntax highlighting for HDL automatically:
syntax on
filetype plugin indent on
To ensure it recognizes .sv files:
au BufRead,BufNewFile *.sv set filetype=verilog
Now Vim will color keywords like module, always, posedge, and endmodule, improving readability while debugging RTL.
8. Real-World Example: VLSI Coding Setup
Goal:
Create a clean environment for RTL, TCL, and C-based scripts.
1. Open .vimrc
vi ~/.vimrc
2. Paste your preferred configuration
3. Reload Vim:
:source ~/.vimrc
4 . Test it by opening a Verilog file:
vi top_module.v
You’ll see syntax colors, auto-indent, and line numbers.
9. Troubleshooting Tips
| Issue | Solution |
| Settings not applied | Run :source ~/.vimrc |
| Syntax colors missing | Check if syntax on is present |
| File not recognized as Verilog | Add au BufRead *.sv set filetype=verilog |
| Errors when opening Vim | Verify .vimrc syntax using vim -V |
Summary
Customizing Vim turns it into a professional-grade editor for VLSI workflows.
With a simple .vimrc setup, you get:
- Clean indentation
- Auto syntax highlighting
- Smooth scrolling and navigation
- Persistent, efficient environment for daily coding
It’s your personalized workspace — ready for design, debug, or scripting tasks.