Memory Decision Feedback Equalizer Inter-Symbol Interference Mitigation

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Solution Overview

Problem

Conventional distortion correction techniques in semiconductor memory devices are inadequate, leading to increased data errors due to inter-symbol interference, which reduces the reliability of data transmission.

Innovation Solution

A decision feedback equalizer (DFE) circuit is employed to correct distortions by using previous bit data to calculate corrective values, allowing for efficient processing of multiple bits simultaneously, thereby mitigating the effects of inter-symbol interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional distortion correction techniques are used, then device complexity is reduced, but data accuracy deteriorates due to inadequate correction of inter-symbol interference

Engineering Contradiction:
Improvedata accuracyVSAvoidcircuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The equalization process is segmented into multiple distinct stages: a first equalization stage that processes signals at a first data rate, and a second equalization stage that processes signals at a second data rate. Each stage uses dedicated circuitry optimized for its specific function, allowing complex correction operations to be broken down into manageable segments that improve data accuracy without requiring a single monolithic complex circuit.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically selects and switches between different equalization modes based on operating conditions. The equalization circuit can operate at different data rates and switch between first and second equalization stages depending on the signal characteristics and interference levels, enabling adaptive correction that maintains high data accuracy across varying operational scenarios.

Inventive Principle:
Principle #15Dynamics

2Productivity

If data transmission rate is increased, then productivity is improved, but reliability deteriorates due to increased inter-symbol interference

Engineering Contradiction:
Improvedata transmission rateVSAvoiddata reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The equalization circuit dynamically adapts its operation based on the data transmission rate. At higher data rates where inter-symbol interference is more severe, the system activates the second equalization stage with its optimized tap coefficients and processing parameters, providing enhanced correction capability that maintains data reliability even as productivity increases through faster transmission.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes key parameters of the equalization process based on operating conditions, including data rate, tap coefficient values, and equalization stage selection. By adjusting these parameters dynamically, the system optimizes the balance between transmission speed and correction effectiveness, ensuring high reliability across different productivity levels.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If single-rate equalization is used, then device complexity is reduced, but adaptability deteriorates unable to handle multiple data rates effectively

Engineering Contradiction:
Improvemulti-rate adaptabilityVSAvoidequalization circuit complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The equalization functionality is segmented into separate first and second equalization stages, each optimized for specific data rate ranges. This segmentation allows the circuit to handle multiple data rates effectively by directing signals to the appropriate stage, providing multi-rate adaptability without requiring a single overly complex circuit that must handle all rates simultaneously.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The equalization circuit is designed with multi-functionality to handle various data rates and signal conditions. By incorporating both first and second equalization stages with different optimization characteristics, the system achieves universal applicability across multiple operating scenarios while maintaining manageable complexity through functional specialization.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentUS20230403184A1Memory decision feedback equalizer
Publication Date: 2023.12.14 MICRON TECHNOLOGY INC
  • US20230403184A1 patent drawing
  • US20230403184A1 patent drawing
  • US20230403184A1 patent drawing

AI summary

A device includes a decoder configured to receive an input signal. The decoder is configured to also output a control signal based on the input signal. The device further includes an equalizer configured to receive a distorted bit as part of a data stream, receive the control signal, select a distortion correction factor based upon the control signal, apply the distortion correction factor to the distorted bit to offset inter-symbol interference from the data stream on the distorted input data to generate a modified value of the distorted bit, and generate a corrected bit based on the modified value of the distorted bit.