Apparatus and a method for managing a memory device based on a read operation
A memory device includes an open memory block and control circuitry. The open memory block includes at least one first page having an erased state. The control circuitry is configured to perform a read operation for a page included in the open memory block, and apply a weight determined based on a ratio of the at least one first page in the open memory block to calculate a read count subject to the read operation.
1 . A memory device comprising:
an open memory block including at least one first page having an erased state; and
control circuitry configured to:
perform a read operation for a page included in the open memory block,
determine a weight based on a ratio of a number of the at least one first page in the open memory block to a total number of pages in the open memory block,
determine a read count subject to the read operation based on the weight, and
control the open memory block based on the read count.
2 . The memory device according to claim 1 , wherein the control circuitry is configured to determine the weight to increase the read count by more than twice in a case that the ratio is greater than a first threshold, compared to when the ratio is equal to or less than the first threshold.
3 . The memory device according to claim 2 , wherein the first threshold is determined based on program/erase (P/E) cycles of the open memory block.
4 . The memory device according to claim 2 , wherein the control circuitry determines the weight higher in a case that a first string of the page in the open memory block shares a layer with a second string in another memory block, compared to when the layer is not shared by the first and second strings.
5 . The memory device according to claim 1 , wherein the control circuitry is configured to determine, when all pages in the open memory block are programmed, the weight higher in a case that a first string of the page in the open memory block shares a layer with a second string in another memory block, compared to when the first string does not share the layer with the second string.
6 . The memory device according to claim 5 , wherein the control circuitry determines the weight higher for the first string than for the second string.
7 . The memory device according to claim 1 , wherein the control circuitry is further configured to perform data migration from the open memory block to a free memory block when the read count determined based on the weight is higher than a second threshold.
8 . The memory device according to claim 1 , wherein the control circuitry is further configured to:
change the open memory block to a closed memory block when the open memory block does not include the at least one first page having the erase state after a program operation; and
determine a read count for the closed memory block without determining the weight.