Seagate Technology Incorporated

Avago Technologies General IP (singapore) Pte. Ltd.

Nanshan Shu

Peng Xu

Jiangang Wu

Zhimin Dong

Alex Ga Hing Tang

LiZhao Ma

Yingyi Ju

A recycling method for a solid state drive is disclosed. The method includes selecting a logical block for recycle wherein the logical block includes a plurality of pages across a plurality of flash dies. The method also includes retrieving an address map index record associated with the logical block selected for recycle. For each particular address map index stored in the address map index record, the recycling method retrieves a set of address map entries referenced by the particular address map index, determines whether any page in the logical block is referenced by the set of address map entries, and if at least one page in the logical block is referenced by the set of address map entries, the method writes the at least one page to a different logical block. The method further includes erasing the plurality of pages in the logical block.

Tracking and utilizing second level map index for recycling of solid state drive blocks

An apparatus having a processor and an interface to a nonvolatile memory having a plurality of blocks is disclosed. The processor is configured to (i) monitor a number of reads since a respective erase in at least one of the blocks in the nonvolatile memory, (ii) move a page from a first block to a second block in response to the number of reads exceeding a first threshold where the first block is partially programmed and (iii) move the page from the first block to the second block in response to the number of reads exceeding a second threshold where the first block is fully programmed. The first threshold is less than the second threshold.

Read disturb handling in NAND flash

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Shanghai, China

Nanshan Shu