Non-volatile Memory Block Wear-Leveling via Read Count Monitoring

The patent implements wear-leveling by discarding frequently read data blocks that exceed a reference read count and recovering them through redistribution to less-worn blocks. The controller monitors read counts for each block and migrates data from worn blocks to fresher blocks, preventing read disturb while maintaining data accessibility. This resolves the contradiction by sacrificing specific individual blocks (discarding them from active use) to protect the overall system reliability.

The patent applies preliminary action by proactively monitoring read counts before read disturb actually occurs. The controller maintains a read count for each data block and compares it against a reference value, performing preventive migration of data blocks that are approaching the threshold. This preliminary intervention prevents the accumulation of excessive read cycles that would lead to voltage drift and read errors, thereby maintaining both access efficiency and read accuracy.

The patent changes the parameter of block selection dynamically based on read count monitoring. Instead of statically assigning data to fixed blocks, the system actively tracks the number of reads for each block and migrates data from blocks with high read counts to blocks with lower read counts. This parameter-based dynamic redistribution ensures that frequently accessed data maintains fast access speeds while the physical wear is distributed across multiple blocks, preventing any single block from reaching its wear limit and causing data loss.