Non-Volatile Memory Read Using Neighbor-Aware Multi-Strobe Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing non-volatile memory systems face challenges in achieving reliable data read processes without significantly increasing read time, particularly when considering the data stored in adjacent memory cells.
Innovation Solution
A multi-strobe sensing process that adjusts sense time for neighbor memory cell threshold voltage and soft bit information, improving data decoding accuracy without elongating the read process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the read process takes into account data stored in adjacent memory cells (neighbor word lines), then data read reliability is improved, but read time increases and becomes slower than desired
Solution Approach 1:
The patent applies preliminary action by performing sensing operations on neighbor memory cells before the actual read operation. The system senses threshold voltage information from adjacent memory cells stored on neighbor word lines in advance, and uses this information to adjust the read process. This preliminary sensing allows the main read operation to benefit from the neighbor cell data without adding significant time overhead, as the neighbor cell sensing is integrated into the read timing sequence.
Solution Approach 2:
The patent implements dynamics by making the read process adaptive based on neighbor memory cell conditions. The system dynamically adjusts read reference voltages or sensing parameters according to the threshold voltage states of adjacent cells. This dynamic adjustment allows the read operation to optimize its parameters in real-time based on the actual neighbor cell data, improving reliability while maintaining efficient read times through intelligent parameter modulation.
2Measurement precision
If sense time is extended to capture neighbor memory cell threshold voltage and soft bit information, then data decoding accuracy is improved, but read process duration increases
Solution Approach 1:
The patent merges multiple sensing objectives into a unified sensing operation. Instead of performing separate sensing operations for neighbor cell threshold voltage and for soft bit information, the system combines these sensing functions into integrated sensing stages. The multi-strobe sensing process simultaneously captures threshold voltage data and soft bit information from both target and neighbor memory cells, achieving high decoding accuracy without proportionally increasing read process duration through operational consolidation.
Solution Approach 2:
The patent employs periodic action through multi-strobe sensing operations that occur at specific timing intervals within the read process. The sensing is performed in periodic pulses (strobos) at optimized moments when the memory cell states are most readable. This periodic sensing approach captures the necessary threshold voltage and soft bit information at critical time points without continuously monitoring, thereby maintaining high measurement precision while limiting the overall read process duration through time-discretized sensing.
Data Source
AI summary
When performing a read process, a non-volatile memory first performs a pre-read sensing of the condition of memory cells connected to neighbor word lines. While applying a first word line voltage associated with a first programmed data state to the selected word line, the memory system performs two sensing operations for the first programmed data state on selected memory cells that have neighbor memory cells on the neighbor word lines in a first condition and perform two sensing operations for the first programmed data state on selected memory cells that have neighbor memory cells on the neighbor word lines in a second condition. Based on that sensing, the data being stored in the set of selected memory cells is determined. In some embodiments, at least one of the two sensing operations for each condition includes sensing soft bit information that improves the data decoding process.