Storage device and method of operating the storage device
AssigneeSamsung Electronics Co., Ltd.
InventorsSang-Soo Cha, Young-Seop Shim, Dae-Won Kim
Life of this patent
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Abstract
A method of operating a storage device includes: performing a background read operation on a nonvolatile memory by using a default read voltage level; performing a read retry operation on the nonvolatile memory by using a corrected read voltage level when the background read operation fails; storing the corrected read voltage level in a history buffer when the read retry operation succeeds; and performing a host read operation on the nonvolatile memory by using the history buffer in response to a read request received from a host.
Claims20
A storage device, comprising:
- a nonvolatile memory including a plurality of memory blocks, wherein each of the memory blocks includes a plurality of pages;
- a history buffer;
- and
- a memory controller configured to execute a background read operation independently of a host device, wherein the background read operation includes scanning the plurality of memory blocks by reading a sampled page among the plurality of pages included in each memory block to store corrected read voltage levels for each memory block in the history buffer, and wherein the corrected read voltage level for each memory block is derived from the sampled page of each memory block,
- wherein the memory controller is further configured to execute, in response to a host read request, a normal read operation of the nonvolatile memory using one of the corrected read voltage levels stored in the history buffer.
A method of operating a storage device, the storage device including a memory controller and a nonvolatile memory including a plurality of memory blocks, each memory block including a plurality of pages, said method comprising:
- performing a normal read operation, wherein in the normal read operation the memory controller reads data from the nonvolatile memory according to a read request received from a host device;
- and
- performing a background read operation which is executed independently of the host device, wherein in the background read operation the memory controller reads a sampled page among the pages of a target memory block to determine a corrected read voltage level of the sampled page, the corrected read voltage level of the sampled page being stored in a history buffer as the corrected read voltage level for the target memory block,
- wherein, in the normal read operation having the read request addressing the target memory block, the memory controller retrieves the corrected read voltage level of the target memory block from the history buffer and the nonvolatile memory uses the corrected read voltage level when reading data from the target memory block.
A method of compensating for drifting of memory cell threshold voltages in a nonvolatile memory device having a plurality of memory blocks, each of the memory blocks including a plurality of pages, the method comprising:
- in a background operation performing a scan of the plurality of memory blocks by reading a sampled page of each memory black among the plurality of pages included in each memory block to populate a history buffer storing corrected read voltage levels for each memory block, wherein the corrected read voltage level for each memory block is derived from the scan of the sampled page of each memory block, and
- receiving a host read request and reading the nonvolatile memory using at least one of the corrected read voltage levels stored in the history buffer.
Dependencies are inferred from the claim text.