Memory system and controller
AssigneeKioxia Corporation
InventorsYoshihisa Kojima, Katsuhiko Ueki
Life of this patent
Estimating the term…
Abstract
In a memory system in an embodiment, in a case of normal operation, a control unit returns a write completion response upon completion of reception of write data from a host, and writes the write data into nonvolatile memory in a multiple values. In a case of unordinary power-off, changeover to operation using a backup battery is conducted and the control unit writes dirty data that is not completed in writing into the nonvolatile memory, into the nonvolatile memory with two values. When next boot, the control unit reads the dirty data from the nonvolatile memory into the volatile memory, and thereafter writes the dirty data into the nonvolatile memory in a multiple values.
Claims20
A memory system comprising:
- a nonvolatile memory;
- a buffer;
- a battery configured to store power on the basis of power supplied from an external supply, and
- a controller configured to:
- in a case where power becomes unsupplied from the external supply, by using the power stored in the battery,
- stop accepting new write commands from a host,
- cancel a first write command received from the host if a completion response for the first write command has not been returned to the host, and
- write second data stored in the buffer into the nonvolatile memory if a completion response for a second write command received from the host has been returned to the host, the second data being data related to the second write command.
A solid state drive (SSD) comprising:
- a NAND flash memory;
- a capacitor configured to store energy on the basis of energy supplied from a power source;
- and
- an SSD controller configured to:
- if a completion response for a first write command received from a host has not been returned to the host in a case where energy becomes unsupplied from the power source, by using energy discharged from the capacitor, stop all new operations to the NAND flash memory for the first write command and abort the first write command received from the host.
Dependencies are inferred from the claim text.