If you’ve ever jumped into someone else’s Verilog code and thought, “What on earth is going on here?” — you’re not alone.
When it comes to writing Verilog, we often focus on whether it works. But in professional environments, how you write your code can make just as much difference as what it does.
Whether you’re building an FPGA prototype, ASIC RTL, or a clean testbench — good coding style is key. Here’s why it matters, with a few real-world examples
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Readable Code = Maintainable Code
Unreadable RTL leads to headaches, confusion, and bugs. Clarity helps everyone — especially future you.
Before:
After:
Just a few tabs and line breaks, and suddenly the logic is crystal clear.
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Consistent Naming Helps Everyone
Stick to naming conventions. Avoid mixing styles like DataBus, databus, and data_bus in the same module. Pick one and be consistent.
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Modularization = Reuse + Testability
Think of each module like a building block. The cleaner it is, the easier it is to plug into larger systems — or reuse later.
Reusing the adder module in a top block called system.
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Good Style Reduces Bugs
One of the most common mistakes in Verilog is mixing blocking (=) and non-blocking (<=) assignments.
Bug prone code:
Correct code:
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Write cleaner testbenches using tasks
The testbenches help us to analyze if the response from the design is matching with the expected results. It is very important to write cleaner and organized code for even testbenches to make them more readable and understandable. Below are two code snippets showcasing how important it is to write a readable testbench.
Testbench 1:
Testbench 2:
Looking at both the code snippets. You can notice Testbench 2 written using tasks appears more readable and clean than Testbench 1. The Testbench 2 is written using tasks in Verilog. Tasks have been written to initialize the inputs, reset the system and drive the stimulus.
Final Takeaway:
Writing Verilog is not just about functionality. It’s about writing RTL that’s understandable, readable, and reliable — especially when working with larger teams or long-term projects.
Following good coding practices is like future-proofing your design process. It saves time, reduces errors, and makes you a better engineer overall whether it is about writing RTL or the testbenches that verify your design.
