Hybrid Memory Data Detection for Multi-Level Cell Read Failure Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multi-level cell (MLC) memory devices face challenges in improving storage density and reliability due to the limited voltage window, leading to increased read-failure rates as the number of bits stored in a single memory cell increases.
Innovation Solution
The proposed solution involves a data detecting apparatus and method that performs soft decision detection based on hard decision reference voltages associated with lower bits, allowing for re-detection of data bits using detection information from both upper and lower bits, thereby improving data accuracy and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the number of bits stored in a single memory cell increases, then storage density is improved, but read-failure rate increases
Solution Approach 1:
The patent segments the detection process into multiple stages: initial hard decision detection, followed by soft decision detection for bits that fail the initial detection. This segmentation allows the system to handle different detection scenarios differently, improving overall reliability while maintaining high storage density.
Solution Approach 2:
The patent performs preliminary hard decision detection on all bits first, then identifies which bits require further soft decision processing. This preliminary action filters out the majority of successfully detected bits, allowing the system to focus computational resources only on bits that need re-detection, thereby improving read reliability efficiently.
2Measurement precision
If soft decision detection is performed for all bits, then data detection accuracy is improved, but detection time and complexity increase
Solution Approach 1:
The patent applies soft decision detection only partially - specifically to those bits that fail the initial hard decision detection, rather than performing it on all bits. This partial application of the more accurate but time-consuming soft decision method achieves the necessary detection accuracy while minimizing the time loss.
Solution Approach 2:
The system uses feedback from the hard decision detection results to determine which bits require soft decision processing. Bits that are successfully detected by hard decision are excluded from soft decision processing, while failed bits are flagged for re-detection using soft decision, creating an efficient feedback-driven detection pipeline.
Data Source
AI summary
The data detecting apparatus may provide a voltage comparison unit that compares a reference voltage, associated with a specific data bit from among a plurality of data bits stored in a memory cell, with a threshold voltage in the memory cell, a detection unit that detects a value of the specific data bit based on a result of the voltage comparison unit, and a decision unit that decides whether the specific data bit is successfully detected based on whether an error occurs in the detected data. The detection unit may re-detect a value of the specific data bit based on detection information with respect to at least one of an upper data bit and a lower data bit in relation to the specific data bit, in response to a result of the decision unit.