Textbook in PDF format This book presents a comprehensive overview of RTL (Register Transfer Level) debugging, addressing both foundational concepts and emerging technologies. It begins by examining the key issues faced in RTL design, such as timing violations, limited signal observability, and complex verification environments. It then outlines the basic principles of RTL debugging, including simulation techniques, waveform inspection, and the use of assertions and testbenches. Traditional debugging methods are discussed in depth, highlighting techniques like print-style debugging, coverage analysis, and assertion-based verification, along with their respective advantages and limitations. The book concludes with an exploration of leading-edge approaches involving Large Language Models (LLMs), showcasing how AI can support RTL debugging by assisting in code comprehension, anomaly detection, and bug localization. The register-transfer level (RTL) abstraction plays a vital role in the modern VLSI design flow. At this stage, designers use hardware description languages such as Verilog and VHDL, or high-level synthesis (HLS) languages like C and C++, to define the precise behavior of digital systems. RTL design offers a wide design space and significant flexibility, enabling designers to make detailed decisions that will strongly influence the final quality of the ASIC in terms of power consumption, performance, and area (PPA). It is crucial to optimize RTL designs thoroughly during this phase, as addressing inefficiencies or poor-quality RTL in later synthesis stages is extremely difficult and often impractical. In the world of RTL (Register Transfer Level) design, understanding the potential hazards before debugging begins can save time and effort in the long run. Identifying and addressing design issues at an early stage prevents costly debugging sessions later in the development process. This chapter categorizes the most common RTL design hazards, grouping them into higher-level categories such as State Management, Signal Integrity, Design Constructs, and Synthesis Considerations. These categories encompass the typical design errors that arise at the RTL level and offer guidance for avoiding these issues before they become a source of debugging challenges. Preface About the Author RTL-Level Design Hazards “A Pre-Debugging Guide” Introduction: Basics of RTL Debugging Conventional Methods for RTL Debugging “Rule-Based Techniques” AI-Driven Methods for RTL Debugging: Localization and Auto-Corrections of RTL Bugs “Towards Smart Debugging” Index