Nonvolatile memory system and related method of performing erase refresh operation
AssigneeSamsung Electronics Co., Ltd.
InventorsSang chul Kang, Seung hyun Han
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Abstract
A memory system comprises a flash memory and a memory controller. The flash memory comprises a plurality of memory blocks. The memory controller performs a read retry operation on a memory block containing an uncorrectable read error until an accurate data value is read from the memory block. The memory controller then controls the flash memory to perform an erase refresh operation on the memory block.
Claims17
A flash memory system, comprising:
- a flash memory comprising a plurality of memory blocks;
- and
- a memory controller that performs multiple successive read retry operations on a memory block in which an uncorrectable read error has been detected in a read operation using a normal read voltage, until a correctable data value is read, and thereafter controls the flash memory to perform an erase refresh operation on the memory block;
- wherein the memory controller performs the read retry operation using a varied read voltage that is produced by incrementing or decrementing the normal read voltage in each of the successive read retry operations according to whether the normal read voltage is designated for reading a first data state or a second data state.
A method of operating a memory device comprising a plurality of memory blocks, the method comprising:
- performing multiple successive read retry operations on a memory block in which an uncorrectable read error has been detected in a read operation using a normal read voltage, until a correctable data value is read from the memory block;
- and
- performing an erase refresh operation on the memory block after at least one of the read retry operations has been performed, in response to read retry information associated with the at least one read retry operation
- wherein the memory controller performs the read retry operations using a varied read voltage that is produced by incrementing or decrementing the normal read voltage in each of the successive read retry operations according to whether the normal read voltage is designated for reading a first data state or a second data state.
A method of operating a nonvolatile memory device comprising a plurality of memory blocks, the method comprising:
- reading data from a selected memory block in a read operation using a normal read voltage;
- detecting whether an uncorrectable error exists in the data;
- upon detecting the uncorrectable error, performing a plurality of read retry operations on the selected memory block using a varied read voltage until a correctable error exists in the data that is read;
- and
- moving the data that has been read to a free memory block and erasing the selected memory block;
- wherein the varied read voltage is incremented or decremented in each successive read retry operation according to whether the normal read voltage is designated for reading a first data state or a second data state.
Dependencies are inferred from the claim text.