Patent ID: 11914896
Assignee: KIOXIA CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. A memory system connectable to a host, the memory system comprising:
a nonvolatile memory; and
a controller configured to control writing data to the nonvolatile memory or reading data from the nonvolatile memory in response to a command from the host, wherein
the nonvolatile memory is configured to correspond to a first mode of writing data of N bits per unit area and a second mode of writing data of M bits (M>N) per unit area, and
the controller is configured to:
receive, from the host, a write command to write write data to the nonvolatile memory,
set a first area and a second area in the nonvolatile memory, the first area being an area to which the first mode is applied in a fixed manner, the second area being an area to which the first mode and the second mode can be applied mixedly;
write, using the first mode, a part or all parts of the write data to a free area of the first area, when the free area is present in the first area;
compare a difference between a size of the write data and a capacity writable using the first mode in the free area of the first area, with a capacity writable using the first mode in a free area of the second area, when the size of the write data is larger than the capacity writable using the first mode in the free area of the first area;
write, using the first mode and to the free area of the second area, all remaining data of the write data after writing to the free area of the first area, when the difference is smaller than or equal to the capacity writable using the first mode in the free area of the second area; and
determine a write capacity of using the first mode in the free area of the second area and a write capacity of using the second mode in the free area of the second area for writing all the remaining data of the write data, such that the write capacity of the first mode in the free area of the second area is maximally utilized, and write all the remaining data of the write data to the determined write capacity using the first mode in the free area of the second area and the determined write capacity using the second mode in the free area of the second area, when the difference is larger than the capacity writable using the first mode in the free area of the second area.