Verilog Design Guide

Verilog is a hardware description language (HDL) used to design, model, simulate, synthesize, and verify digital electronic systems such as FPGA and ASIC designs. It is defined by IEEE 1364, and modern Verilog features are now part of the SystemVerilog IEEE 1800 standard.

Unlike software programming languages, Verilog describes hardware that operates concurrently. Modules, wires, registers, and always blocks all execute in parallel, reflecting the actual behavior of digital circuits.

Why Use Verilog?

Verilog bridges the gap between abstract circuit description and physical hardware:

• RTL Design: Write Register Transfer Level code that tools can synthesize into gates.

• Simulation: Test designs before committing to silicon or an FPGA bitstream.

• Verification: Apply structured testbenches to confirm correct behavior.

• Portability: The same RTL can target FPGAs and ASICs with minimal changes.

Documentation Sections

Getting Started

• First Verilog Project
  • Project Goal
  • Required Tools
  • Create the Source File
  • Write the Verilog Module
  • Create a Testbench
  • Run Simulation
  • Synthesize and Program the FPGA
  • Next Steps
  • Recommended Reading
• Verilog Data Types
  • 4-State Logic Values
  • wire
  • reg
  • Vectors
  • integer
  • parameter and localparam
  • Arrays and Memories
  • Complete Data Type Example
  • Summary
  • See Also
• Common Verilog Design Examples
  • Combinational Logic
  • Sequential Logic
  • Parameterized Modules
  • Synthesis-Friendly Style
  • See Also

Core Concepts

• Procedural Blocks in Verilog
  • initial Block
  • always Block
  • Sensitivity Lists
  • Blocking Assignment (=)
  • Non-Blocking Assignment (<=)
  • Combinational Logic with always
  • Sequential Logic with always
  • Assignment Rule Summary
  • See Also
• Finite State Machines in Verilog
  • What is an FSM?
  • Moore vs Mealy Machines
  • State Encoding
  • 3-Block FSM Template
  • Example: Traffic Light Controller
  • Common Mistakes
  • See Also
• Verilog Testbenches
  • What is a Testbench?
  • Clock Generation
  • Reset Initialization
  • Checking Output Behavior
  • Waveform Dumping
  • Complete Testbench Example
  • Running the Simulation
• Verilog Packages
  • Defining a Package
  • Importing a Package
  • Package Use Cases
  • Synthesis Considerations

Advanced Topics

• SystemVerilog Overview
  • Key Design Enhancements
  • Interfaces
  • Verification Features
  • SystemVerilog vs. Verilog
  • Tool Support
  • External Tech Resources
• Nios II and Verilog
  • What is a Soft Processor?
  • Processor System Architecture
  • The Avalon Memory-Mapped Interface
  • Connecting Custom Verilog Logic
  • Nios II Workflow
  • Memory-Mapped Peripheral Access
  • Custom Instruction Acceleration
  • Summary
• Verilog vs VHDL
  • What is VHDL?
  • Syntax Comparison
  • Typing Differences
  • Design Flow Similarities
  • Mixed-Language Design
  • When to Choose Verilog
  • When to Choose VHDL
  • SystemVerilog as a Modern Choice

Standards and References

• IEEE 1364-2005 — Verilog HDL: A formal notation for creating, verifying, synthesizing, testing, and maintaining electronic systems.

• IEEE 1800 — SystemVerilog: Extends Verilog with stronger typing, interfaces, assertions, classes, and advanced verification features.

• FPGA and ASIC Design Practice — Verilog is widely used in RTL design, simulation, synthesis, and hardware verification.

External Resources

• Technolati — Technolati.com: A valuable resource for staying updated on the latest technology trends and news.