FPGA Internal PLL Phase Alignment for Low-Latency Clock Sync
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Field programmable gate arrays (FPGAs) face a technical challenge in synchronizing receiver and transmitter clock signals, which introduces unwanted latency and delays in processing, particularly in high-frequency applications like high-frequency trading where microsecond accuracy is crucial.
Innovation Solution
A field programmable gate array system with an external or internal phase controller that aligns the receiver and transmitter clock signals by using a phase detector and controller to adjust the phase difference, eliminating the need for clock domain crossing circuits and minimizing latency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If clock domain crossing circuits are used to synchronize receiver and transmitter clocks, then phase synchronization is achieved, but processing latency increases
Solution Approach 1:
The patent extracts the phase alignment function from the data path by using a dedicated phase detector and controller that operate independently on clock signals. This separates the synchronization function from the data processing path, eliminating the need for clock domain crossing circuits in the critical data path and thus reducing processing latency while maintaining phase synchronization.
Solution Approach 2:
The patent introduces a phase detector as an intermediary component that compares receiver and transmitter clocks and generates control signals for a phase controller. This intermediary mechanism enables precise phase alignment without requiring the data to traverse complex synchronization circuits, thereby maintaining low latency while achieving reliable phase synchronization.
2Reliability
If phase alignment circuits are added to synchronize clocks, then clock synchronization is improved, but device complexity increases
Solution Approach 1:
The patent segments the clock synchronization function into distinct modular components: a phase detector that compares clock phases and a phase controller that adjusts the transmitter clock based on detection results. This segmentation allows each component to perform its specific function efficiently without requiring complex integrated circuits, thereby achieving reliable clock synchronization with manageable device complexity.
3Reliability
If synchronous Ethernet protocols are used, then frequency synchronization is achieved, but phase measurement capability is lost
Solution Approach 1:
The patent implements a feedback mechanism where the phase detector continuously monitors the phase difference between receiver and transmitter clocks and provides real-time control signals to the phase controller. This closed-loop feedback system enables precise phase measurement and adjustment, going beyond the open-loop frequency synchronization of synchronous Ethernet protocols and providing both frequency and phase alignment capabilities.
Data Source
AI summary
The present invention relates to a field programmable gate array system that provides phase control with minimal latency.