Clock Phase Adjustment via CDR-Directed Digital Calibration
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Solution Overview
Problem
Existing clock and data recovery (CDR) circuitry in electronic devices often requires additional calibration circuitry that can be costly and power-intensive, leading to phase errors in clock signal timing, especially at high data rates.
Innovation Solution
The implementation of a CDR-directed phase error detection unit and new baud-rate timing recovery equations allows for in-run calibration of clock signals using control information, reducing the need for extra calibration circuitry and enabling phase error correction in the digital domain, thereby minimizing power consumption and device area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If extra calibration circuitry is added to control clock signal timing, then timing accuracy is improved, but device complexity and power consumption increase
Solution Approach 1:
The patent combines the calibration function with the existing CDR circuitry by having the CDR unit generate control information that is fed back to adjust clock signal timing. This merging eliminates the need for separate calibration circuitry while maintaining timing accuracy through integrated phase error detection and correction mechanisms.
Solution Approach 2:
The CDR circuitry is designed to perform multiple functions: both clock recovery and calibration of clock signal timing. By making the CDR unit universal, it can detect phase errors and generate control information for timing adjustment without requiring dedicated calibration hardware, thus reducing device complexity while improving timing accuracy.
2Measurement precision
If extra calibration circuitry is added to control clock signal timing, then timing accuracy is improved, but power consumption increases
Solution Approach 1:
The calibration function is merged into the existing CDR circuitry, allowing timing accuracy improvement without adding separate power-consuming calibration hardware. The integrated approach uses the same circuit resources for both clock recovery and timing calibration.
Solution Approach 2:
The CDR circuitry performs self-calibration by detecting phase errors in the recovered clock signal and automatically generating control information to adjust timing. This self-service mechanism eliminates the need for external calibration circuitry and reduces overall power consumption while maintaining timing accuracy.
3Measurement precision
If clock phase calibration is performed in analog domain, then timing accuracy is improved, but device area and power consumption increase
Solution Approach 1:
The patent replaces analog calibration mechanisms with digital domain operations. The CDR unit operates in the digital domain to detect phase errors and generate control information, substituting complex analog calibration circuitry with simpler digital logic that achieves comparable or superior phase calibration accuracy while reducing device area and power consumption.
Data Source
AI summary
Some embodiments include apparatus and methods using clock generation circuitry to generate a first clock signal and a second clock signal based on an input clock signal, the first and second clock signals having different phases, sampler circuitry to sample an input signal based on timing of the first and second clock signals and provide data information and error information associated with sampling of the input signal, a clock and data recovery unit to generate first control information based on the data information and the error information, and a phase error detection unit to generate second control information based on the data information and the error information, the clock generation circuitry to control timing of the input clock signal based on the first control information and to control timing of the first and second clock signals based on the second control information.