What are the challenges and solutions in multi-clock domain design?

Multi-clock challenges: CDC verification (ensure proper synchronization on all crossing signals), timing closure (each domain may have different frequency/constraints), reset synchronization (async reset must be synchronized to each domain), and clock generation (PLLs, dividers, muxing). Solutions: Systematic CDC analysis using tools like Spyglass CDC, proper synchronizer insertion (2FF for single-bit, FIFO/handshake for multi-bit), Gray coding for counters crossing domains, and careful reset tree design. Verification requires CDC-aware simulation, formal CDC checks, and post-layout STA with realistic clock uncertainties.