Retimer Link Training for High-Speed Serial Communication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing link training solutions for high-speed serializer-deserializer communication are limited as they perform link training only once during startup, failing to adapt to changing parameters such as temperature and signal voltage levels over time, which affects bit-error rate and interference on adjacent channels.
Innovation Solution
Implementing continuous or periodic link training using a link training communication channel that persists after initialization, allowing for updates to operating parameters of transmitters and receivers, and utilizing retimers to extend transmission line reach, with methods including stealing overhead from the Physical Coding Sublayer or adding low-frequency signaling on top of higher-frequency data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If link training is performed only once during startup, then user data transmission is not interfered with, but link quality deteriorates due to changing parameters like temperature and voltage over time
Solution Approach 1:
The patent implements periodic link training by inserting training sequences at regular intervals during data transmission. The transmitter periodically inserts training sequences into the data stream, and the receiver uses these sequences to update equalizer coefficients and adapt to channel changes, thereby maintaining link quality without continuous interference to user data.
Solution Approach 2:
The patent performs preliminary link training during the startup phase to establish initial communication parameters before user data transmission begins. This preliminary action configures the basic link characteristics, allowing subsequent periodic training to focus only on adapting to environmental changes rather than establishing connections from scratch.
2Reliability
If continuous link training is implemented, then link quality is maintained under changing conditions, but user data transmission is interfered with
Solution Approach 1:
The patent applies partial action by inserting training sequences at specific intervals rather than continuously throughout the data stream. This partial inclusion of training sequences provides sufficient channel information for adaptation while minimizing the proportion of bandwidth consumed by training, thus maintaining both link quality and data transmission efficiency.
Solution Approach 2:
The patent segments the data transmission into intervals where training sequences are inserted periodically rather than continuously. This segmentation allows the system to alternate between training phases and data transmission phases, ensuring that link adaptation occurs without continuously interfering with user data flow.
3Adaptability or versatility
If existing link training solutions are used, then implementation is simple, but adaptability to changing channel conditions is insufficient
Solution Approach 1:
The patent implements feedback mechanisms where the receiver measures channel quality using inserted training sequences and sends feedback information to the transmitter. The transmitter uses this feedback to adjust its transmission parameters, creating a closed-loop system that continuously adapts to changing channel conditions while maintaining manageable complexity through standardized feedback protocols.
Solution Approach 2:
The patent enables the communication system to self-adjust to channel changes by automatically inserting training sequences and updating equalizer coefficients without external intervention. The system serves itself by monitoring its own performance and making real-time adjustments to maintain optimal link quality under varying environmental conditions.
Data Source
AI summary
The present disclosure is directed to systems, apparatuses, and methods for performing continuous or periodic link training. Existing link training protocols generally perform link training only once during startup or initialization of a link and, as a result, are limited in their applications. After link training is performed and Open Systems Interconnect (OSI) data link layer and other high-layer data is transmitted across the link, no further link training is performed using these existing link training protocols. However, parameters of the link may change over time after link training is performed, such as temperature of the link and voltage levels of signals transmitted over the link by the transmitter of the transmitter-receiver pair.