Storage device including nonvolatile memory device and operating method of storage device
A storage device, including a nonvolatile memory device including a plurality of memory cells forming a user area and a reserved area; and a controller configured to perform a write operation on at least one write unit included in the plurality of memory cells, and to perform an erase operation on at least one erase unit included in the plurality of memory cells, wherein the controller includes an internal buffer, wherein the controller is configured to: perform a backup operation by writing first data stored in the internal buffer in a backup erase unit included in the reserved area, and after performing the backup operation adjust a buffering unit of the internal buffer to correspond to a cell type of the backup erase unit.
1 . A storage device comprising:
a nonvolatile memory device comprising a plurality of memory cells forming a user area and a reserved area; and
a controller configured to perform a write operation on at least one write unit included in the plurality of memory cells, and to perform an erase operation on at least one erase unit included in the plurality of memory cells,
wherein the controller comprises an internal buffer,
wherein the controller is configured to:
receive a first write request including first data to be written into the user area from an external host device,
store the first data in the internal buffer,
perform a first backup operation by moving the first data from the internal buffer to a backup erase unit included in the reserved area, wherein the backup erase unit corresponds to a first cell type,
after performing the first backup operation, adjust the internal buffer to correspond to the first cell type,
receive a second write request including second data to be written into the user area from the external host device,
store the second data in the internal buffer,
perform a second backup operation by moving the second data from the internal buffer to the backup erase unit, and
based on determining that a combined page size of the first data and the second data stored in the backup erase unit is equal to a target page size corresponding to a second cell type, migrate the first data and the second data from the backup erase unit to a target erase unit included in the user area, wherein the target erase unit corresponds to the second cell type.
2 . The storage device of claim 1 , wherein a combination of the first data and the second data comprises third data corresponding to the second cell type.
3 . The storage device of claim 2 , wherein, after migrating the third data from the backup erase unit to the target erase unit, the controller is further configured to adjust the internal buffer to correspond to the second cell type.
4 . A storage device comprising:
a nonvolatile memory device comprising a plurality of memory cells forming a user area and a reserved area; and
a controller configured to perform a write operation on at least one write unit included in the plurality of memory cells, and to perform an erase operation on at least one erase unit included in the plurality of memory cells,
wherein the controller comprises an internal buffer comprising zone buffers, and is configured to:
allocate a plurality of zones to a storage space of the user area of the nonvolatile memory device based on a request received from an external host device,
select two or more erase units from among a plurality of erase units included in the plurality of memory cells to be allocated to each of the plurality of zones based on a zone map table,
fixedly and sequentially manage logical addresses of data written in the plurality of zones,
receive a first write request including first write data to be written into the user area from the external host device,
store the first write data in the internal buffer,
perform a first backup operation for buffer data stored in the internal buffer by moving the buffer data to a backup erase unit included in the reserved area, wherein the backup erase unit corresponds to a first cell type,
select a zone based on features of zones associated with backup data stored in the backup erase unit, and
migrate data corresponding to the selected zone from the backup erase unit to the selected zone,
wherein, after performing the first backup operation, the controller is further configured to:
adjust the zone buffers corresponding to the zones associated with the buffer data stored in the backup erase unit to correspond to the first cell type,
receive a second write request including second write data to be written into the user area from the external host device,
store the second write data in the internal buffer,
perform a second backup operation for the buffer data stored in the internal buffer by moving the buffer data to the backup erase unit, and
based on determining that a combined page size of the first write data and the second write data stored in the backup erase unit is equal to a target page size corresponding to a second cell type, migrate the first write data and the second write data from the backup erase unit to a target erase unit included in the user area, wherein the target erase unit corresponds to the second cell type.
5 . The storage device of claim 4 , wherein, based on first data corresponding to a first zone which corresponds to the first cell type from among the zones being received from the external host device and stored in a first zone buffer of the internal buffer corresponding to the first zone, the controller is further configured to write the first data in the backup erase unit.
6 . The storage device of claim 5 , wherein, based on accumulated data associated with the first zone accumulated in the backup erase unit corresponding to a cell type of the first zone, the controller is further configured to migrate the accumulated data to the first zone.
7 . The storage device of claim 6 , wherein, after migrating the accumulated data to the first zone, the controller is further configured to adjust a cell type of data stored in the first zone buffer to correspond to the cell type of the first zone.
8 . A storage device comprising:
a nonvolatile memory device comprising a plurality of memory cells; and
a controller configured to perform a write operation on at least one write unit included in the plurality of memory cells, and to perform an erase operation on at least one erase unit included in the plurality of memory cells,
wherein the controller comprises an internal buffer and is configured to:
receive a first write request including first data to be written into a target erase unit from an external host device,
store the first data in the internal buffer,
move the first data from the internal buffer to a reserved erase unit, wherein the reserved erase unit corresponds to a first cell type,
after moving the first data to the reserved erase unit, adjust the internal buffer to correspond to the first cell type, and determine a migration order for backup data stored in the reserved erase unit based on features of target erase units, wherein the target erase unit corresponds to a second cell type,
receive a second write request including second data to be written into the target erase unit from the external host device,
store the second data in the internal buffer,
move the second data from the internal buffer to the reserved erase unit, and
based on determining that a combined page size of buffer data stored in the reserved erase unit is equal to a target page size corresponding to the second cell type, migrate the buffer data from the reserved erase unit to the target erase units based on the migration order, and
wherein the buffer data comprises the first data and the second data.
9 . The storage device of claim 8 , wherein the controller is further configured to:
calculate invalid ratios corresponding to the backup data for each target erase unit of the target erase units; and
determine the migration order based on the invalid ratios.
10 . The storage device of claim 9 , wherein the controller is further configured to select a target erase unit having a highest invalid ratio from among the target erase units to be a first target erase unit in the migration order.
11 . The storage device of claim 8 , wherein the controller is further configured to:
calculate write speeds corresponding to the backup data for each target erase unit of the target erase units; and
determine the migration order based on the calculated write speeds.
12 . The storage device of claim 11 , wherein the controller is further configured to select a target erase unit having a highest write speed from among the target erase units to be a first target erase unit in the migration order.
13 . The storage device of claim 8 , wherein the controller is further configured to migrate the backup data in a power-saving mode.
14 . The storage device of claim 8 , wherein the controller is further configured to migrate the backup data in an idle state.
15 . The storage device of claim 8 , wherein the reserved erase unit comprises a write booster buffer corresponding to a universal flash storage (UFS) standard.
16 . The storage device of claim 15 , wherein the controller is further configured to perform a backup operation based on determining that a write booster is activated.
17 . The storage device of claim 8 , wherein a storage space of the nonvolatile memory device comprises a user area and a reserved area,
wherein the external host device is configured to request data to be written in the user area, and
wherein the reserved erase unit is selected from among erase units of the reserved area.
18 . The storage device of claim 17 , wherein the controller is further configured to perform a backup operation based receiving a flush request or a power off notification (PON) from the external host device.
19 . The storage device of claim 1 , wherein the internal buffer is adjusted to correspond to one from among a quadruple level cell (QLC) type, a triple level cell (TLC) type, a multi level cell (MLC) type, and a single level cell (SLC) type.