Read Voltage Level Correction for Non-Volatile Memory
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Rewritable non-volatile memory modules face challenges in maintaining optimal read voltage levels due to changing operating and environmental conditions, leading to increased error bits and reduced efficacy in data read operations, especially when the host system is powered off or in low power mode.
Innovation Solution
A read voltage level correction method that uses a transient look-up table to record association information between initial and successfully used read voltage levels, allowing for fine-tuning of previously monitored optimal read voltage levels, thereby reducing the time to find a suitable read voltage level and enhancing data read operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the memory storage device continuously monitors the optimal read voltage level, then the accuracy of read voltage level is improved, but the time interval between actual data reading and monitoring becomes excessively long when the host system is powered off or in low power mode
Solution Approach 1:
The patent applies preliminary action by continuously monitoring and recording the optimal read voltage level in advance when the host system is active. The monitoring results are stored so that when the actual data reading occurs later (after power off or low power mode), the pre-recorded optimal read voltage level can be directly used, eliminating the need for time-consuming re-monitoring.
Solution Approach 2:
The patent uses copying by creating a record (copy) of the optimal read voltage level monitoring results. This recorded information is then reused during actual data reading operations, avoiding the need to perform the same monitoring process again and reducing the time interval issue.
2Ease of operation
If the memory storage device uses a preset read voltage level, then the operation is simple, but the threshold voltage shift due to changing operating and environmental conditions causes too many error bits
Solution Approach 1:
The patent implements feedback by continuously monitoring the optimal read voltage level and using this information to adjust the read voltage level for subsequent data reading operations. The monitoring results are fed back into the read operation to ensure accuracy despite threshold voltage shifts caused by changing conditions.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the read voltage level based on monitored optimal values and environmental conditions. Instead of using a fixed preset voltage, the system changes the voltage parameter according to actual conditions, improving reliability while maintaining operational simplicity through automated adjustment.
3Measurement precision
If the memory storage device performs optimal read voltage level tracking operation, then the read voltage level accuracy is improved, but the complexity of the system increases due to continuous monitoring and recording requirements
Solution Approach 1:
The patent applies self-service by enabling the memory storage device to automatically monitor, record, and adjust its own read voltage level without requiring external intervention. The system performs self-diagnosis and self-correction, reducing the need for complex external monitoring equipment while maintaining high accuracy.
4Use of energy by stationary object
If the host system is powered off or enters low power consumption mode, then the power saving is achieved, but the interval between actual data reading and previous monitoring time becomes excessively long causing optimal read voltage level to shift
Solution Approach 1:
The patent applies preliminary action by continuously monitoring and recording the optimal read voltage level in advance while the host system is powered on. This pre-recorded information remains valid even when the system enters low power mode or is powered off, allowing accurate read operations to resume quickly without requiring continuous power consumption for monitoring.
Data Source
AI summary
A read voltage level correction method, a memory storage device, and a memory control circuit unit are provided. The method includes: using a first read voltage level as an initial read voltage level to perform a first data read operation on a first physical unit among multiple physical units to obtain a second read voltage level used to successfully read the first physical unit; recording association information between the first read voltage level and the second read voltage level in a transient look-up table; and performing a second data read operation according to a read level tracking table and the association information recorded in the transient look-up table.