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About the Book

WARNING: The main goal of this book is to test Leanpub functionality, and all the information in this book can be found in my articles for the Interrupt by Memfault and PlatformIO blogs.

So, there is no need to buy this book—you should only do so if you prefer reading information in book format or if you just want to buy me a coffee. :)

Diving into JTAG is your ultimate guide to understanding and mastering the JTAG protocol, a critical tool for embedded systems development. Whether you are an engineer, student, or enthusiast, this book provides a clear and comprehensive exploration of JTAG, from its fundamental principles to advanced applications.

Starting with the basics of the IEEE 1149.1 standard, the book delves into the architecture of JTAG, including Test Access Ports (TAPs), Instruction Registers (IR), Data Registers (DR), and the Boundary Scan Register (BSR). You’ll gain a solid understanding of how JTAG facilitates debugging, testing, and analysis in modern embedded systems.

Key topics include:

• The principles of JTAG operation and its role in embedded systems.
• The structure and functionality of key JTAG components.
• The Boundary Scan method for PCB testing.
• Security considerations for JTAG implementations.

This book is a valuable resource for anyone interested in understanding the core mechanisms behind this critical protocol, paving the way for more advanced studies or practical applications.

About the Author

Aliaksandr Kavalchuk

I`m a seasoned Firmware Engineer with over a decade of hands-on experience in embedded systems development, microcontroller programming, and low-level debugging. My professional journey spans full-cycle product development — from schematic design and PCB layout to firmware architecture and production-ready code — across diverse industries, including industrial automation, wearable technology, and data storage.

I have contributed to mission-critical products for companies such as Grundfos (industrial dosing pumps), KIOXIA (enterprise SSDs), and numerous IoT and consumer electronics startups. I`m proficient in C/C++, Python, and RTOS/Linux-based systems, with deep expertise in protocols like UART, SPI, I2C, and 1-Wire, as well as hardware debugging via JTAG, SWD, and logic analyzers.

Beyond my engineering work, I`m an active technical writer. My publications include the books “Wired Protocols in Embedded Systems” and “Diving into JTAG”, along with in-depth articles featured on platforms like Memfault, PlatformIO Labs, and Medium. My goal is to demystify complex technical concepts and explain them in a clear, practical manner.