Memory system and control method
AssigneeToshiba Memory Corporation
InventorsYoshihisa Kojima, Masanobu Shirakawa, Kazutaka Takizawa, Hiroyuki Moro, Takuya Futatsuyama
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Abstract
A memory system includes a nonvolatile memory a controller that controls the nonvolatile memory, and a backup power supply. In response to a detection that power from an external source to the memory system is interrupted, at which time power to the memory system starts to be supplied from the backup power supply, the controller transmits a first command to the nonvolatile memory to change a parameter for a write operation and then transmits a second command to the nonvolatile memory to carry out a write operation, such that the nonvolatile memory carries out the write operation using the changed parameter.
Claims19
A memory system comprising:
- a nonvolatile memory including a plurality of memory cells and a plurality of word lines;
- a controller configured to control the nonvolatile memory;
- and
- a backup power supply,
- wherein, in response to a detection that power from an external source to the memory system is interrupted, at which time power to the memory system starts to be supplied from the backup power supply, the controller:
- transmits a first command to the nonvolatile memory to change a parameter for a write operation on first memory cells, which are electrically connected to a first word line and are in an erased state;
- and then
- transmits a second command to the nonvolatile memory to carry out the write operation on the first memory cells, such that the nonvolatile memory carries out the write operation using the changed parameter.
A memory system comprising:
- a nonvolatile memory that includes a plurality of blocks, including a first block and a second block;
- and
- a controller that controls the nonvolatile memory,
- wherein the controller, in response to a shutdown event, transmits a first command to the nonvolatile memory to write data into the first block, and in response to a power restore event that follows the shutdown event, transmits a second command to the nonvolatile memory to relocate the data written into the first block to the second block, and
- wherein during the relocating, the controller transmits a third command to the nonvolatile memory to set a read pass voltage to a first read pass voltage and, after the relocating, the controller transmits a fourth command to the nonvolatile memory to set the read pass voltage to a second read pass voltage that is lower than the first read pass voltage.
Dependencies are inferred from the claim text.