Adaptive De-emphasis Training for High-Speed Serial Bus Connections

The patent implements preliminary de-emphasis training before actual data transmission begins. The transmitter sends training patterns at multiple de-emphasis levels, and the receiver analyzes these patterns to determine the optimal de-emphasis level for the specific cable and connection conditions. This preliminary action allows the system to adapt to cable characteristics beforehand, ensuring reliable data transmission without requiring complex real-time adjustments during normal operation.

The patent employs feedback mechanisms where the receiver provides information about signal quality and de-emphasis performance back to the transmitter. The transmitter uses this feedback to adjust de-emphasis levels dynamically during training and to lock in the optimal settings for data transmission. This feedback loop enables the system to automatically adapt to changing conditions without manual intervention, managing complexity through automated control.

The patent applies partial action by testing de-emphasis at a limited set of predetermined levels rather than continuously adjusting across all possible values. The transmitter sends training patterns at specific de-emphasis levels (e.g., 0, 1, 2) and uses the receiver's feedback to identify the optimal level. This discrete approach reduces the time required for training compared to exhaustive search methods, while still achieving sufficient connection quality for reliable data transmission.

The patent performs de-emphasis training as a preliminary step before actual data transmission begins. By completing the training and determining optimal parameters in advance, the system ensures that subsequent data transmission can proceed at full speed without time-consuming adjustments. The training overhead is concentrated in the setup phase, after which the optimal parameters are maintained consistently throughout operation.

The patent transitions from fixed de-emphasis to dynamic, adaptive de-emphasis that adjusts to specific cable conditions. The system determines the optimal de-emphasis level through training and can adjust it dynamically based on detected signal quality and cable characteristics. This dynamic approach allows the system to maintain high transmission speeds while compensating for cable-induced signal degradation and inter-symbol interference, achieving both speed and reliability.

The patent changes the de-emphasis parameter from a fixed value to an adaptive parameter that varies based on cable length, quality, and operating conditions. Through training, the system identifies the specific de-emphasis parameter value that optimizes signal quality for each connection. This parameter adaptation enables the system to maintain accurate signal transmission at high speeds across different cable conditions, eliminating the trade-off between speed and signal integrity.