Storage Device Encoding Method for Multi-Threshold Memory Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor memory devices are scaled down for higher integration and capacity, they face issues such as data loss, leading to decreased reliability due to the challenges of managing and storing data effectively across multiple threshold voltage states.
Innovation Solution
An operating method for a storage device that involves encoding write data based on its significance, using a memory controller to determine whether the data is LSB, CSB, or MSB, and adjusting the number of bits accordingly to reduce the number of bits corresponding to the highest threshold voltage state, thereby optimizing data storage and retrieval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If data is stored in nonvolatile memory with multiple threshold voltage states to achieve high integration and capacity, then storage capacity increases, but data loss occurs and reliability decreases
Solution Approach 1:
The patent applies preliminary action by encoding data before writing to memory, specifically by determining whether data is LSB or non-LSB and applying different encoding schemes in advance. This preprocessing prevents data loss before it occurs during storage, rather than attempting correction after retrieval. The encoding is performed before the actual write operation to mitigate reliability issues inherent in multi-state memory storage.
Solution Approach 2:
The patent changes the parameter of data encoding based on the significance of the data being stored. LSB data receives one encoding treatment while non-LSB data receives a different encoding treatment that considers both current and previous data values. This parameter change in encoding strategy allows the system to optimize for both capacity utilization and data reliability depending on the specific data characteristics.
2Reliability
If encoding is applied to all write data to improve reliability, then data loss is reduced, but processing complexity and time increase
Solution Approach 1:
The patent segments the encoding process into two distinct paths based on data type: LSB data encoding and non-LSB data encoding. This segmentation allows the system to apply different levels of encoding complexity appropriate to each data type, reducing overall processing complexity while maintaining reliability. LSB data receives simpler encoding while non-LSB data receives more comprehensive encoding that includes previous data values.
Solution Approach 2:
The patent applies partial action by selectively applying different encoding strategies based on data significance rather than uniformly encoding all data. LSB data receives minimal necessary encoding while non-LSB data receives more extensive encoding. This partial differentiation reduces processing complexity for the majority of data while providing enhanced protection where needed.
3Quantity of substance
If the number of threshold voltage states is increased to store more bits per cell, then storage density improves, but the difficulty of detecting and measuring data accurately increases
Solution Approach 1:
The patent applies preliminary encoding to data before storage, which prepares the data in a format that is more resilient to detection errors. By encoding LSB and non-LSB data differently in advance, the system creates a more robust representation that can withstand the increased difficulty of accurately detecting multiple threshold voltage states, thereby maintaining detection accuracy despite higher storage density.
Data Source
AI summary
The operating method of the storage device includes receiving write data to be written at the plurality of memory cells; determining whether the received write data is LSB data to be written at the plurality of memory cells; and encoding the write data according to the determination. The write data is encoded according to the write data when the write data is LSB data to be written at the plurality of memory cells. The write data is encoded according to the write data and encoding data of lower data of the write data to be written at the plurality of memory cells when the write data is not LSB data to be written at the plurality of memory cells.