Memory Erase Retention Control for Charge Gain Reliability

The patent applies preliminary action by performing erase operations in advance on memory blocks that are invalidated or no longer needed, rather than waiting until they are actually needed for new writes. This creates a pool of pre-erased blocks ready for immediate use, eliminating the need to perform erase operations during sequential write operations, thus maintaining both data reliability and write throughput

The patent applies local quality by performing charge gain checks selectively on specific memory blocks that have been erased and are candidates for reuse, rather than checking all erased blocks uniformly. This targeted approach ensures that blocks with charge gain issues are identified and handled appropriately while minimizing the impact on overall read window budget and maintaining high write throughput

The patent applies segmentation by dividing the memory space into distinct pools: a free pool of pre-erased blocks ready for use, a valid pool of blocks containing current data, and a pool of blocks undergoing charge gain checks. This segmentation allows charge gain checks to be performed on a manageable subset of blocks rather than all erased memory, reducing system complexity while maintaining data reliability through targeted verification