Clock Data Recovery Circuit with Adaptive Signal Selection

The patent applies preliminary action by performing channel evaluation and signal quality assessment before the clock data recovery process. The receiver evaluates channel characteristics and signal power levels in advance, then pre-selects the appropriate clock data recovery mode (DPLL or CDR) based on the evaluation results. This preliminary assessment prevents ISI-related failures by choosing the appropriate recovery method before processing high-speed signals, thereby maintaining reliability while enabling high transmission speeds.

The patent implements dynamics by making the equalization process adaptive rather than static. The system dynamically adjusts whether to apply equalization based on real-time channel evaluation and signal power measurements. When the channel quality is good and signal power is sufficient, equalization is bypassed to reduce complexity. When channel conditions deteriorate or signal power drops below thresholds, equalization is activated to maintain signal quality. This dynamic adaptation resolves the contradiction between reliability and device complexity.

The patent applies parameter changes by dynamically adjusting signal processing parameters based on channel evaluation results. Instead of simply increasing signal power, the system changes processing parameters such as selecting different clock data recovery modes (DPLL for lower speeds, CDR for higher speeds), adjusting equalization coefficients, and modifying sampling timing based on measured channel characteristics and signal power levels. This parameter adaptation improves signal detection accuracy while avoiding the harmful effects of excessive power amplification that would cause distortion.