Storage device including nonvolatile memory device and controller with varied read weights

    公开(公告)号:US10049755B2

    公开(公告)日:2018-08-14

    申请号:US15423629

    申请日:2017-02-03

    IPC分类号: G11C16/34 G06F3/06 G11C16/04

    摘要: A storage device includes a nonvolatile memory device and a controller. The nonvolatile memory device includes multiple memory blocks, each of which includes memory cells. The controller reads data from selected memory cells of a memory block selected from the memory blocks during a read operation. The selected memory cells correspond to both a word line and a string selection line selected as a read target. The controller increases a read count by a read weight corresponding to the selected word line and string selection line of the selected memory block, and performs a refresh operation on the selected memory cells if the read count reaches a threshold value. In the selected memory block, two or more read weights are assigned according to locations of the string selection lines and the word lines.