Flash Memory Soft Data Detection with Single Stepped Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing memory technologies face challenges in accurately determining the state of flash memory cells due to mechanisms like read disturb and charge loss, leading to errors that are not efficiently corrected by traditional error correction codes.
Innovation Solution
A method is introduced to determine soft data associated with the state of a memory cell by performing a single stepped sense operation, which also determines the quality and confidence of the hard data, thereby improving accuracy and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional error correction codes are used to correct errors in flash memory cells, then error correction is achieved, but the process is inefficient and cannot handle errors caused by read disturb and charge loss effectively
Solution Approach 1:
The patent performs a preliminary stepped sense operation to determine soft data before final hard data determination. This preliminary action captures threshold voltage information at multiple voltage levels, creating a foundation for more effective error correction that accounts for read disturb and charge loss effects.
Solution Approach 2:
The patent transitions from traditional binary hard data to multi-level soft data by introducing threshold voltage measurements at multiple voltage levels. This dimensional expansion from 1-bit to multi-bit soft data provides richer information for error correction, enabling the system to distinguish between actual data changes and those caused by read disturb or charge loss.
2Measurement precision
If multiple sense operations are performed to determine soft data accurately, then measurement precision is improved, but time consumption increases
Solution Approach 1:
The patent merges multiple sense operations into a single integrated stepped sense operation. By applying multiple read voltages in sequence during one operation and capturing threshold voltage information at each step, the system achieves the measurement precision of multiple operations without the time penalty, as all measurements are performed in a unified process rather than separate operations.
Solution Approach 2:
The stepped sense operation maintains continuous useful action by performing threshold voltage measurements at multiple voltage levels without interrupting the sense process. The operation continuously gathers soft data information throughout the voltage stepping sequence, maximizing information extraction from a single continuous operation rather than performing discrete separate measurements.
Data Source
Figure 1
Figure 2~3
Figure 4A~4B
AI summary
The present disclosure includes apparatuses and methods for determining soft data. A number of embodiments include determining soft data associated with a data state of a memory cell. In a number of embodiments, the soft data may be determined by performing a single stepped sense operation on the memory cell.