Back to results
US 7,467,253 B2Granted
Cycle count storage systems
AssigneeSanDisk Corporation
InventorEmilio Yero
Life of this patent
Estimating the term…
Abstract
A hot count records the number of erase operations experienced by a block. The hot count is stored in an overhead data area of the block and is updated by circuits located on the same substrate as the block. Where a memory has two or more planes, each plane has circuits for updating hot counts.
Claims18
A flash memory array comprising:
- a memory chip comprising a plurality of planes, each one of the plurality of planes having dedicated row and column decoder circuits, each plane having one or more blocks, each plane of the plurality of planes having a register, each plane having an incrementing circuits, and each plane having a comparing circuit;
- and
- a controller chip comprising a memory controller that is in communication with the memory chip, the memory controller requests the memory chip to erase one or more of the blocks;
- the register for a first plane of the planes receives a hot count from a first block of the one or more blocks for the first plane, the hot count indicating the number of times the first block has been erased;
- the incrementing circuit for the first plane increments the contents of the register for the first plane in response to a request from the memory controller to erase the first block;
- and
- the comparing circuit for the first plane compares the contents of the register for the first plane with a predetermined value.
4 more elements
A NAND flash memory array having a page as the unit of programming and a block as the unit of erase, a block containing two or more pages, comprising:
- a block having a host data area and an overhead data area, the overhead data area containing a hot count that records the number of times the block has been erased, the block located on a first substrate;
- a comparing circuit that compares the hot count with a threshold value, the comparing circuit on the first substrate;
- and
- a controller on a second substrate, the controller managing data storage in the memory array.
1 more element
Dependencies are inferred from the claim text.