Memory system

A memory system comprising:

• a non-volatile memory including a first sub-memory region, a second sub-memory region, a third sub-memory region, a fourth sub-memory region, a fifth sub-memory region, and a sixth sub-memory region;
• and
• a controller, wherein
• each of the first sub-memory region, the second sub-memory region, the third sub-memory region, the fourth sub-memory region, the fifth sub-memory region, and the sixth sub-memory region including a plurality of memory cells, and
• the controller is configured to:
• calculate a first voltage corresponding to the first sub-memory region in first processing;
• before the first processing, use a second voltage as a first common voltage when reading data from each of the first sub-memory region, the second sub-memory region, and the fourth sub-memory region, use a third voltage corresponding to the third sub-memory region when reading data from the third sub-memory region, and use a fourth voltage as a second common voltage when reading data from each of the fifth sub-memory region and the sixth sub-memory region;
• when a first condition is satisfied in the first processing, after the first processing, use the first voltage when reading data from the first sub-memory region, use as the first common voltage a fifth voltage calculated by using the first voltage when reading data from each of the second sub-memory region and the fourth sub-memory region, use the third voltage when reading data from the third sub-memory region, and use the fourth voltage when reading data from each of the fifth sub-memory region and the sixth sub-memory region;
• and
• when a first condition is not satisfied in the first processing, after the first processing, use the first voltage when reading data from the first sub-memory region, use the second voltage as the first common voltage when reading data from each of the second sub-memory region and the fourth sub-memory region, use the third voltage when reading data from the third sub-memory region, and use as the second common voltage a sixth voltage calculated by using the first voltage when reading data from each of the fifth sub-memory region and the sixth sub-memory region.

A memory system, comprising:

• a non-volatile memory including a first memory region and a second memory region;
• and
• a controller, wherein
• each of the first memory and the second memory region including a plurality of sub-memory regions, each sub-memory region including a plurality of memory cells, and
• the controller is configured to:
• use a first common voltage corresponding to the first memory when reading data from each of the sub-memory regions included in the first memory region;
• and
• use a second common voltage corresponding to the second memory region and independent of the first common voltage when reading data from each of the sub-memory regions included in the second memory region;
• the controller is further configured to, when a first sub-memory region in the first memory region satisfies a first condition:
• calculate a first voltage corresponding to the first sub-memory region;
• calculate a second voltage based on the first voltage;
• and
• apply the second voltage as the first common voltage;
• the controller is further configured to, after applying the second voltage as the first common voltage:
• use the first common voltage when reading data from each of the sub-memory regions, excluding the first sub-memory region, included in the first memory region;
• and
• use the first voltage when reading data from the first sub-memory region.

A memory system, comprising:

• a non-volatile memory including a first memory region and a second memory region;
• and
• a controller, wherein
• each of the first memory and the second memory region including a plurality of sub-memory regions, each sub-memory region including a plurality of memory cells, and
• the controller is configured to:
• use a first common voltage corresponding to the first memory when reading data from each of the sub-memory regions included in the first memory region;
• and
• use a second common voltage corresponding to the second memory region and independent of the first common voltage when reading data from each of the sub-memory regions included in the second memory region;
• the controller is further configured to, when a fourth sub-memory region of the sub-memory regions included in the first memory region satisfies a third condition:
• calculate a fifth voltage corresponding to the fourth sub-memory region;
• and
• use the fifth voltage when reading data from the fourth sub-memory region;
• and
• use the first common voltage when reading data from each of the sub-memory regions, excluding the fourth sub-memory region, included in the first memory region.