Gating Circuit for SDRAM Timing Signal Filtering

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Solution Overview

Problem

Existing memory controller systems face challenges in accurately filtering timing signals from SDRAM memory modules due to clock jitter and changes in temperature or voltage, leading to incorrect filtering operations and potential data corruption.

Innovation Solution

A self-adjusting, closed-loop feedback system that uses a gating circuit and timing control circuit to generate a control signal that adjusts based on temporal variations in the timing signal, ensuring the gating window aligns with the rising or falling edges of the signal, thereby eliminating tri-state regions and improving data transfer accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a static, pre-determined filtering operation is used on the timing signal, then the filtering operation is simple to implement, but it cannot compensate for variable timing due to clock jitter, temperature, or voltage changes, leading to incorrect filtering and data corruption

Engineering Contradiction:
Improvefiltering operation implementationVSAvoidfiltering accuracy
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies dynamics by transitioning from a static filtering operation to a dynamic one. The filtering operation is now adjusted in real-time based on detected temporal variations in the timing signal. The system continuously monitors timing variations caused by clock jitter, temperature, or voltage changes and dynamically modifies the filtering parameters accordingly, ensuring accurate filtering under varying operating conditions while maintaining system reliability.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the gating window is fixed at a predetermined time interval, then the system operation is simple, but it cannot adapt to temporal variations in the timing signal, causing erroneous data read operations

Engineering Contradiction:
Improvegating window controlVSAvoidtiming accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent implements feedback by continuously monitoring the timing signal for temporal variations and using this information to adjust the gating window timing. The system detects variations caused by clock jitter, temperature, or voltage changes and feeds this information back to dynamically reposition the gating window. This feedback mechanism ensures the gating window remains accurately aligned with the timing signal edges despite environmental variations, maintaining measurement precision while adapting to changing conditions.

Inventive Principle:
Principle #23Feedback

3Device complexity

If no adjustment for temporal variations is made, then the system complexity is low, but clock jitter and environmental changes cause incorrect filtering operations and data corruption

Engineering Contradiction:
Improvesystem structureVSAvoiddata integrity
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies self-service by enabling the system to automatically detect and compensate for its own temporal variations without external intervention. The timing control circuit continuously monitors the timing signal for variations caused by clock jitter, temperature, or voltage changes and autonomously adjusts the gating window and filtering operations accordingly. This self-adjusting mechanism maintains data integrity and system reliability while minimizing the need for external calibration or manual intervention.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2721500B1System and method for DQS gating
Publication Date: 2015.08.12 MARVELL WORLD TRADE LTD
  • EP2721500B1 patent drawingFigure 1
  • EP2721500B1 patent drawingFigure 2
  • EP2721500B1 patent drawingFigure 3

AI summary

Systems and methods are provided for timing read operations with a memory device. A system for timing read operations with a memory device includes a gating circuit configured to receive a timing signal from the memory device. The gating circuit is further configured to pass through the timing signal as a filtered timing signal during a gating window. The gating window is generated by the gating circuit based on a control signal. The system further includes a timing control circuit configured to generate the control signal after receiving a read request from a memory controller. The timing control circuit is further configured to adjust the control signal to account for temporal variations in the timing signal from the memory device.