Memory Decoding Using Neighbor Threshold Voltage Differences
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Non-volatile memory devices, such as USB flash memory and removable storage cards, face errors due to cross-coupling effects between adjacent memory cells, leading to inaccurate data reading and decoding.
Innovation Solution
The system decodes data from a first group of storage elements by utilizing data from a second group of storage elements and their physical characteristics, specifically using error correction codes and the difference between predicted and read threshold voltages to account for cross-coupling effects, thereby improving data reading accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If process advances enable smaller physical dimensions of memory cells, then storage density increases, but cross-coupling effects between neighboring cells become more pronounced
Solution Approach 1:
The patent measures the cross-coupling effects (harmful factor) by reading threshold voltages of neighboring storage elements, then uses this measured information to compensate for the coupling effects during decoding. This converts the harmful cross-coupling into useful information that improves decoding accuracy of the target storage elements.
2Reliability
If error correction code processing is used to correct reading errors, then data reliability improves, but decoding complexity increases
Solution Approach 1:
The patent performs preliminary measurement of cross-coupling effects by reading threshold voltages of neighboring storage elements before the main decoding process. This preliminary action provides compensation information that simplifies the subsequent ECC decoding by pre-characterizing the coupling effects, reducing the complexity of the overall decoding process.
Solution Approach 2:
The patent introduces an intermediary measurement step that reads threshold voltages of neighboring storage elements. This intermediary information acts as a mediator between the physical cross-coupling effects and the logical decoding process, enabling more accurate error correction without requiring complex decoding algorithms.
3Measurement precision
If fine reading resolution is used to accurately detect threshold voltages, then measurement precision improves, but reading time increases
Solution Approach 1:
The patent performs fine-resolution threshold voltage readings on only the neighboring storage elements (partial action) rather than all storage elements in the memory array. This selective measurement provides sufficient precision for measuring cross-coupling effects while minimizing the time penalty associated with high-resolution readings.
Data Source
AI summary
Systems and methods to decode data stored in a data storage device are disclosed. Data bits stored in a first group of storage elements are decoded using data in a second group of storage elements together with physical characteristics of the second group of storage elements to aid in the decoding of the first group of storage elements.