Memory Controller Backup Power Write Parameter Adaptation
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Solution Overview
Problem
Existing memory systems face challenges in efficiently writing unwritten data, including 'dirty data,' into non-volatile memory when power from an external source is interrupted, as they rely on a limited auxiliary power supply with a restricted operational time.
Innovation Solution
A memory system comprising a non-volatile memory, a controller, and a backup power supply that initiates a write operation using changed parameters when external power is interrupted, ensuring efficient data writing into the non-volatile memory using the backup power supply before it depletes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the auxiliary power supply is used to write unwritten data when external power is interrupted, then data integrity is maintained, but the operational time is limited by the auxiliary power supply capacity
Solution Approach 1:
The patent changes the write operation parameters (program voltage level, write speed) to match the auxiliary power supply's limited capacity. By using reduced program voltages and optimized write sequences, the system can complete data writing within the constrained energy budget of the auxiliary power supply, thereby maintaining data integrity while respecting the limited operational time.
Solution Approach 2:
The system prioritizes writing only the most critical unwritten data (dirty data in the write buffer) when external power is interrupted, rather than attempting to write all pending data. This partial action approach ensures that essential data is preserved within the limited time window provided by the auxiliary power supply.
2Productivity
If the write operation is performed with standard parameters, then writing speed is maintained, but the auxiliary power supply depletes too quickly
Solution Approach 1:
The patent dynamically adjusts write operation parameters based on the available power supply capacity. When auxiliary power is detected, the system modifies program voltage levels, write pulse widths, and verification frequencies to reduce power consumption while maintaining acceptable writing speed. This allows the system to balance productivity with the constrained energy availability of the auxiliary power supply.
Solution Approach 2:
The write operation is structured as a series of periodic verify-and-program cycles with optimized timing. By using periodic verification at strategically spaced intervals rather than continuous verification, the system reduces overall power consumption while still ensuring write completion within the auxiliary power supply's operational window.
3Productivity
If the program voltage is increased to speed up writing, then writing efficiency improves, but power consumption exceeds the auxiliary power supply capacity
Solution Approach 1:
The patent implements adaptive program voltage selection that adjusts voltage levels based on the detected power supply type. When auxiliary power is detected, the system uses optimized voltage profiles with lower peak voltages and adjusted voltage application durations. This parameter optimization maintains writing efficiency within the reduced power envelope of the auxiliary power supply.
Solution Approach 2:
The write operation uses dynamic voltage adjustment where program voltage levels are modified in real-time based on feedback from verification results. This allows the system to use higher voltages only when necessary for difficult writes and lower voltages for easier writes, optimizing the balance between writing efficiency and power consumption during auxiliary power operation.
Data Source
AI summary
A memory system includes a nonvolatile memory a controller that controls the nonvolatile memory, and a backup power supply. In response to a detection that power from an external source to the memory system is interrupted, at which time power to the memory system starts to be supplied from the backup power supply, the controller transmits a first command to the nonvolatile memory to change a parameter for a write operation and then transmits a second command to the nonvolatile memory to carry out a write operation, such that the nonvolatile memory carries out the write operation using the changed parameter.