Non-volatile Memory Read-Voltage Adjustment for Flash Error Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flash memory technologies face reading errors due to data retention and disturb issues, which cause data voltage offsets, leading to incorrect read-voltage levels and increased error bits, especially as memory cell geometries shrink and densities increase.
Innovation Solution
A non-volatile memory apparatus with an on-the-fly self-adaptive read-voltage adjustment method that dynamically adjusts read-voltage parameters based on error bit analysis, using both lower and higher read-voltage parameters to correct data voltage offsets and minimize errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If flash memory uses smaller geometries and higher density to reduce costs, then manufacturing cost is reduced and storage capacity increases, but reading error rate increases due to data voltage offset
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the read-voltage parameter based on detected error patterns. The controller modifies the read-voltage parameter in response to voltage offsets caused by data retention and disturb issues, thereby compensating for the increased error rate inherent in high-density memory configurations without requiring hardware redesign.
2Ease of operation
If flash memory uses fixed read-voltage parameter, then device operation is simple, but data reading error increases when voltage offset occurs
Solution Approach 1:
The patent implements feedback by having the controller monitor read operations and detect error bits, then use this information to adjust the read-voltage parameter dynamically. This closed-loop approach maintains operational simplicity from the user perspective while internally adapting to voltage offsets to prevent reading errors.
Solution Approach 2:
The patent applies dynamics by transitioning from a static read-voltage parameter to a dynamic one that adjusts in real-time based on detected voltage offsets and error patterns. The read-voltage parameter becomes adaptive, changing according to the actual state of the memory cells during operation.
3Quantity of substance
If flash memory increases density with more bits per memory cell, then storage capacity increases, but data voltage offset to lower or higher voltage occurs causing reading errors
Solution Approach 1:
The patent addresses the voltage level accuracy issue by dynamically changing the read-voltage parameter in response to detected errors. When voltage offsets push data voltages outside the acceptable decision threshold range, the controller adjusts the read-voltage parameter to realign the decision boundary with the shifted voltage distributions.
Data Source
AI summary
A non-volatile memory apparatus includes a non-volatile storage circuit and a controller. The non-volatile storage circuit reads a corresponding data voltage set, and converts the corresponding data voltage set to the corresponding data in accordance with the read-voltage parameter of the controller. The controller decides whether to perform the on-the-fly self-adaptive read-voltage adjustment in accordance with the number of error bits of the corresponding data. The on-the-fly self-adaptive read-voltage adjustment includes: providing a left (or lower) read-voltage parameter to the non-volatile storage circuit for converting the corresponding data voltage set to the left corresponding data; providing a right (or higher) read-voltage parameter to the non-volatile storage circuit for converting the corresponding data voltage set to the right corresponding data; and deciding the adjusting-direction and the adjusting-amount of the read-voltage parameter in accordance with the relationship between the corresponding data, the left corresponding data and the right corresponding data.