Adaptive Block Allocation in Nonvolatile Memory
AssigneeSanDisk Technologies LLC
InventorsNarendhiran Chinnaanangur Ravimohan, Muralitharan Jayaraman, Abhijeet Manohar, Alan Bennett
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Abstract
In a multi-plane non-volatile memory, good blocks of different planes are linked for parallel operation for storing long host writes. Where bad blocks in one or more planes result in unlinked blocks, the unlinked blocks are configured for individual operation to store short host writes and/or memory system management data. Unlinked blocks may be configured as Single Level Cell (SLC) blocks while linked blocks may be configured as SLC blocks or Multi Level Cell (MLC) blocks.
Claims18
A method of operating a multi-plane flash memory array comprising:
- identifying bad blocks in a first plane of the multi-plane flash memory array and designating a first number of good blocks of the first plane for storage of user data;
- identifying bad blocks in a second plane of the multi-plane flash memory array and designating a second number of good blocks of the second plane for storage of user data, the second number being greater than the first number;
- linking the first number of good blocks of the first plane with good blocks of the second plane to form the first number of metablocks, each of the first number of metablocks configured for parallel operation across the first and second planes;
- identifying a third number of good blocks in the second plane that are not linked, the third number being equal to the second number minus the first number;
- and
- configuring the third number of good blocks in the second plane for individual operation to store selected data.
A multi-plane nonvolatile memory system comprising:
- a first plane that includes a first number of good blocks;
- a second plane that includes a second number of good blocks that is greater than the first number;
- a first number of metablocks, an individual metablock formed from one good block of the first plane linked with one corresponding good block from the second plane;
- and
- a third number of individually operated blocks in the second plane that are not linked with any blocks of the first plane, the third number equal to the second number minus the first number.
Dependencies are inferred from the claim text.