Nonvolatile Memory Data Integrity via Reference Latch Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Nonvolatile memory devices face reliability issues due to the loss of setup data when power becomes unstable, affecting their operation and data integrity.
Innovation Solution
A memory system with a controller that senses and re-senses setup data based on changes in reference data stored in latch units, ensuring data reliability by reloading setup data when the reference data is corrupted or changed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If setup data is stored in latch units during power-up, then the memory operation can be initialized, but the data may be lost when power becomes unstable
Solution Approach 1:
The system performs preliminary actions by storing reference data in latch units during initial power-up before any unstable power events occur. This preliminary storage enables subsequent detection and recovery operations when power instability is detected, allowing the system to restore setup data from the memory cell array using the preserved reference data as a guide.
Solution Approach 2:
The system implements feedback by continuously monitoring the stability of power supply and comparing it against predetermined thresholds. When power instability is detected, the system triggers a recovery process that reads reference data from latch units and uses it to restore setup data, creating a closed-loop system that adapts to power conditions and maintains data integrity through feedback-driven recovery operations.
2Reliability
If the system monitors power stability and re-senses setup data, then data reliability is improved, but device complexity increases
Solution Approach 1:
The system extracts the critical function of reference data storage from the main setup data storage location by using separate latch units to store only the reference data portion. This extraction allows the majority of the data storage function to remain in the non-volatile memory cell array, while a small, dedicated portion handles the power-stability-dependent reference data, simplifying the overall control logic by separating concerns.
Solution Approach 2:
The system creates a copy of the reference data in latch units during power-up, which serves as a backup guide for recovery operations. This copying mechanism provides a simplified recovery process where the system only needs to transfer and process the reference data copy rather than reconstructing the entire setup data structure, thereby reducing the complexity of the control logic required for power failure recovery.
3Reliability
If reference data is stored in latch units, then power instability detection is enabled, but energy consumption increases
Solution Approach 1:
The system performs the energy-intensive action of storing reference data in latch units during the initial power-up phase when power stability is already established. By completing this preliminary action before any power instability occurs, the system avoids the need for continuous real-time monitoring and active recovery operations, thereby minimizing overall energy consumption while still enabling reliable power instability detection.
Solution Approach 2:
The system uses the power supply itself as the monitoring mechanism, leveraging the inherent voltage levels to indicate power stability conditions. This self-service approach eliminates the need for separate, energy-consuming monitoring circuits, as the power supply's own characteristics provide the feedback signal for detecting instability, thereby reducing additional energy consumption while maintaining detection capability.
Data Source
AI summary
A memory system includes a nonvolatile memory and a controller. The nonvolatile memory includes a memory cell array storing setup data and reference data, and first and second latch units respectively configured to store the setup data and the reference data sensed from the memory cell array upon a power-up of the memory system. The controller is configured to control a sensing operation of the nonvolatile memory. An operating environment of the nonvolatile memory is determined by the setup data stored in the first latch unit, and the controller controls the nonvolatile memory to re-store the setup data of the memory cell array in the first latch unit when the reference data of the second latch unit is changed.