Verilog HDL Tutorial

Welcome to our comprehensive Verilog tutorial! Whether you're a complete beginner or brushing up on fundamentals, this series will teach you everything you need to know about the world's most popular hardware description language.

What is Verilog?

Verilog is a Hardware Description Language (HDL) used to model electronic systems. Originally developed by Gateway Design Automation in 1984, it became an IEEE standard (IEEE 1364) in 1995.

Think of Verilog as a way to "describe" hardware in text format. Instead of drawing circuit diagrams, you write code that represents the same logic. This code can then be:

Simulated – Test your design before building it
Synthesized – Converted into actual hardware (ASIC, FPGA)
Verified – Check that it behaves correctly

Why Learn Verilog?

Verilog is the foundation of VLSI design and verification. Here's why it matters:

Industry Standard – Used by Intel, AMD, NVIDIA, Qualcomm, and virtually every semiconductor company
Essential for SystemVerilog – SystemVerilog is built on top of Verilog; you must know Verilog first
FPGA Development – The primary language for Xilinx and Intel (Altera) FPGAs
Job Requirement – Every RTL design and verification job requires Verilog knowledge

Is Verilog Still Used in 2026?

Absolutely. While SystemVerilog dominates verification (testbenches), pure Verilog (IEEE 1364-2001) is still widely used for RTL Design.

Many IP blocks, legacy cores, and especially FPGA synthesis tools have rock-solid support for Verilog 2001. Learning Verilog ensures you can read and debug the actual hardware code beneath the fancy UVM testbench.

Verilog vs SystemVerilog

SystemVerilog (IEEE 1800) extends Verilog by adding verification features like classes, randomization, and assertions. Learn Verilog first, then move to SystemVerilog tutorials.

A Simple Example

Let's look at a simple 2-input AND gate in Verilog:

Verilog - AND Gate

module and_gate (
    input  wire a,
    input  wire b,
    output wire y
);
    assign y = a & b;  // Continuous assignment
endmodule

This short code defines a complete hardware module! Let's break it down:

module – Keyword to start a hardware block
input/output – Port directions
wire – Data type for connections
assign – Continuous (combinational) logic
endmodule – End of the module

What You'll Learn

This tutorial series covers everything from basic syntax to advanced modeling:

Fundamentals

Basic Syntax – Comments, identifiers, modules
Data Types – wire, reg, integer, real
Operators – Arithmetic, logical, bitwise, reduction

Design Constructs

Modules – The building blocks of Verilog designs
Ports – Connecting modules together
Always Blocks – Sequential and combinational logic
Assign Statement – Continuous assignment

Control Flow & Advanced

Conditionals – if-else, case, casex, casez
Loops – for, while, repeat, forever
Generate Blocks – Creating parameterized hardware

Simulation & Synthesis

Testbench Basics – Writing simulation environments
Synthesis – Turning code into hardware

Prerequisites

You don't need any prior hardware knowledge to start! However, these will help:

Basic understanding of digital logic (AND, OR, NOT gates)
Familiarity with any programming language (C, Python, etc.)
Understanding of binary numbers

Ready to begin? Click Next below to learn about Verilog syntax!

Next Verilog Basic Syntax