Storage Device Sudden Power Off Recovery Using Threshold Voltage Read
Solution Overview
Problem
Storage devices face challenges in recovering program operations interrupted by sudden power offs, as existing technologies do not effectively manage memory cell threshold voltages, leading to data loss and inefficient use of memory blocks.
Innovation Solution
A storage device and method that utilize a memory controller to perform reprogram operations on interrupted pages by using threshold voltages to differentiate between recoverable and irrecoverable pages, employing default, lower, and upper read voltages to determine the state of memory cells and perform appropriate reprogram operations, such as storing garbage data or modified program data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a program operation is interrupted due to sudden power off, then data loss occurs and memory block utilization becomes inefficient, but existing technologies cannot effectively recover the interrupted operation without consuming additional memory blocks
Solution Approach 1:
The patent applies parameter changes by utilizing multiple read voltages (default read voltage, lower read voltage, and upper read voltage) to detect the threshold voltage state of memory cells. By changing the voltage parameters during read operations, the system can accurately determine whether a program operation was successfully interrupted or completely failed, enabling appropriate recovery actions without consuming additional memory blocks.
Solution Approach 2:
The patent implements feedback mechanisms by reading the interrupted page using multiple voltage levels and using the read results to determine the next action. The memory controller receives feedback from read operations at different voltages and adjusts its recovery strategy accordingly - either performing a reprogram operation with original data, modified data, or garbage data based on the detected threshold voltage distribution.
2Measurement precision
If multiple read voltages are used to determine memory cell states, then measurement precision improves for recovering interrupted operations, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the threshold voltage detection process into distinct stages using different read voltages. First, a default read voltage is used for initial assessment, then lower and upper read voltages are used for more precise threshold determination. This segmented approach to voltage application allows accurate measurement of memory cell states while keeping the control logic manageable through structured, stepwise processing.
Data Source
AI summary
A storage device may perform a reprogram operation on a page on which a program operation is interrupted due to a sudden power off. The storage device may include a memory device including a plurality of memory blocks, each of which includes a plurality of pages, and a memory controller configured to perform a reprogram operation on a page in which a program operation is suspended using reprogram data that is set depending on threshold voltages of memory cells included in the page on which the program operation is interrupted, among the plurality of pages.