Patent ID: 11941247
Assignee: KIOXIA CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. A storage device, comprising:
a non-volatile memory including a plurality of blocks, each of the blocks being a unit of data erasing; and
a control unit that is electrically connected to the non-volatile memory and that is configured to control the non-volatile memory, wherein
the control unit is configured to:
manage a plurality of management areas obtained by logically partitioning storage area of the non-volatile memory,
manage a reference time of the storage device,
when a write request is received that includes data for which a valid term has been set, determine, based on the valid term and the reference time, a first management area from among the plurality of management areas, the valid term being a term during which the data is to be stored in the storage device,
write the data included in the write request to the determined first management area, and
when the data written to the determined first management area is erased, erase all data written in the first management area which includes the data;

non-overlapping valid terms are respectively assigned to the plurality of management areas;
the control unit is configured to determine the first management area which has been assigned the valid term that includes an end time of the valid term set for the data included in the write request;
the plurality of management areas includes the first management area to which a first valid term is assigned and a second management area to which a second valid term longer than the first valid term is assigned;
when the first valid term assigned to the first management area has elapsed, the second valid term assigned to the second management area is shortened based on the first valid term; and
when the valid term assigned to the first management area to which the data is written has elapsed, the control unit is configured to collectively erase all data written to the first management area.