This textbook Digital Design: HDL-Based Approach presents Digital Electronics and Logic Design fundamentals with HDL-Based Design in a motivating and thorough manner. It is designed for a one-semester course at the undergraduate level and also provides contents for B. Tech programs for Electrical, Electronics and Communication, Computer Science and other associated engineering disciplines. Although the authors have assumed that readers possess elementary knowledge of electronic devices and circuits, all fundamental concepts of this subject have been touched upon for the sake of clarity.