PAM Multi-Lane Clock Alignment Using Transmitter-Side Skew Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing communication systems are inadequate for high-speed data communication applications, particularly in aligning data from multiple communication lanes due to skew issues, which are difficult and costly to correct at the receiver end.
Innovation Solution
A communication system with a skew management module that generates a control current based on output test patterns from multiple communication lanes, using a comparator to create an analog offset signal, which is integrated into a Phase-Locked Loop (PLL) to adjust clock signals and align data segments, enabling effective skew removal at the transmitter end.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If skew correction is performed at the receiver end, then data alignment can be achieved, but the system complexity and cost increase significantly
Solution Approach 1:
The patent inverts the conventional approach by performing skew correction at the transmitter end rather than the receiver end. The skew management module measures skew between communication lanes and applies correction signals to the transmitter's clock signals, thereby eliminating the need for complex receiver-end correction mechanisms while achieving the same data alignment precision
Solution Approach 2:
The patent implements preliminary skew correction at the transmitter before data transmission. The skew management module measures and corrects skew between communication lanes in advance, so that data segments are already aligned when transmitted, eliminating the need for complex real-time correction at the receiver end
2Productivity
If multiple communication lanes are used to increase bandwidth, then data throughput improves, but skew between lanes becomes more difficult to manage
Solution Approach 1:
The skew management module serves multiple communication lanes simultaneously with a single unified measurement and correction mechanism. It measures skew between all lanes and generates appropriate correction signals for each lane's PLL, providing a universal solution that scales with the number of lanes without proportionally increasing system complexity
Solution Approach 2:
The patent introduces a skew management module as an intermediary between the communication lanes and their respective PLLs. This module measures skew between lanes and acts as a mediator by generating correction signals that are fed back to the PLLs, thereby coordinating the clock signals across multiple lanes and simplifying skew management
3Productivity
If high-speed PAM communication is implemented, then spectral efficiency improves, but skew between communication lanes increases
Solution Approach 1:
The patent implements a feedback mechanism where the skew management module continuously measures the skew between communication lanes and feeds correction signals back to the PLLs. This closed-loop feedback system dynamically adjusts the clock signals to maintain precise data alignment even at high speeds where skew is more pronounced
Solution Approach 2:
The patent adjusts the clock signal parameters (phase and frequency) through the PLLs based on skew measurements. By dynamically changing these parameters in response to measured skew, the system maintains precise data alignment across communication lanes operating at high speeds with PAM modulation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution allows for efficient alignment and removal of skew between communication lanes, improving data transfer throughput and accuracy by correcting skew at the transmitter end, thereby enhancing the performance of high-speed communication systems.
Implementation Method 1
The charge pump is configured to store the control current and characterized by a control voltage
Implementation Method 2
The comparator is configured to generate the analog offset signal by comparing the control voltage to a predetermined reference voltage
Implementation Method 3
A PLL of one of the communication lanes generates a corrected clock signal that is adjusted using the analog offset signal to remove or adjust the skew between the communication lanes
Data Source
AI summary
The present invention is directed to communication systems. According to embodiments of the present invention, a communication system includes at least two communication lanes and a skew management module. The skew management module generates a control current based on output test patterns of the two communication lanes. The control current is integrated and compared to a reference voltage by a comparator, which generates an analog offset signal. A PLL of one of the communication lanes generates a corrected clock signal that is adjusted using the analog offset signal to remove or adjust the skew between the communication lanes. The corrected clock signal is used for output data. There are other embodiments as well.