Flash Storage Controller LBA Mismatch Retry Mechanism
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Solution Overview
Problem
Data storage devices using flash memory face reliability issues when external impacts or hardware errors occur, leading to incorrect data read operations due to incorrect translation of logical block addresses to physical page numbers.
Innovation Solution
A data storage device with a buffer to store a mapping table of physical block addresses corresponding to logical block addresses, and a controller that re-reads data from non-volatile memory if the read data does not match the requested logical block address, ensuring reliability and speed by referring to operation history stored in a cache.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the data storage device uses a mapping table to translate LBA to PPN, then the data read operation is performed, but external impact or hardware error may cause reading data at a wrong position instead of the requested LBA
Solution Approach 1:
The controller implements a feedback mechanism by comparing the LBA value in the read data with the requested LBA. When a mismatch is detected, the system triggers a retry of the read operation, using the comparison result to feedback control whether to re-read the data, thereby ensuring data integrity despite external impacts or hardware errors
Solution Approach 2:
The system performs a preliminary check by comparing the LBA in the read data with the requested LBA immediately after reading. This preliminary validation action allows the system to detect errors before proceeding with data processing, enabling early intervention through retry operations when errors are detected
2Reliability
If the controller retries reading data when LBA mismatch is detected, then data reliability is improved, but additional read operations increase time consumption
Solution Approach 1:
The system applies partial action by performing the time-consuming retry operation only when necessary - specifically when an LBA mismatch is detected. Instead of always retrying or never retrying, the system selectively retries based on the comparison result, thus balancing reliability improvement with time efficiency by avoiding unnecessary re-read operations
Data Source
AI summary
A data storage device is provided. The data storage device a buffer configured to store a mapping table comprising physical block addresses (PBAs) corresponding to logical block addresses (LBAs), a non-volatile memory configured to store data; and a controller configured to control the buffer and the non-volatile. The controller is configured to read data stored at a first PBA of the non-volatile memory corresponding to a first LBA by referring to the mapping table when receiving a command to read data corresponding to the first LBA from outside of the data storage device, and, when a second LBA included in the data read from the non-volatile memory is different from the first LBA, retry reading, from the non-volatile memory, the data corresponding to the first LBA.