Memory device capable of changing pass voltage, memory system, and operating method of the memory device
According to the inventive concept, a memory device may receive a pass voltage signal set in advance from a host and perform a verification operation with respect to a memory cell array based on the received pass voltage signal. The memory device includes an aggressor word line on which a read operation is performed, and a memory block including a victim word line adjacent to the aggressor word line, and a change in a read voltage with respect to the memory block is recorded and the recorded change in the read voltage is sent to the host.
1 . A memory device comprising:
a memory cell array,
wherein the memory cell array comprises:
an aggressor word line on which a read operation is performed; and
a memory block including a victim word line that is adjacent to the aggressor word line,
wherein the memory device is configured to perform a verification operation on the memory cell array based on a pass voltage signal,
wherein a change in a read voltage with respect to the memory block is recorded as a recorded change in the read voltage,
wherein the memory device is configured to change a pass voltage based on the recorded change in the read voltage, and
wherein the memory device is configured to, when a preset number of read operations is exceeded, change the pass voltage based on the recorded change in the read voltage.
2 . The memory device of claim 1 , wherein the change in the pass voltage includes providing an offset to the pass voltage, and
wherein the change in the pass voltage is based on an equation that is predetermined.
3 . The memory device of claim 2 , wherein the change in the pass voltage is based on a distribution of respective threshold voltages of memory cells included in the memory cell array, and
wherein the change in the pass voltage is based on a preset ratio between a maximum value and a minimum value of the distribution of the threshold voltages.
4 . The memory device of claim 3 , wherein the preset ratio between the minimum value and the maximum value in the distribution of the threshold voltages is 1:0.93.
5 . The memory device of claim 1 , wherein the change in the pass voltage includes an offset to the pass voltage, and
wherein the change in the pass voltage is based on a table value that is predetermined.
6 . The memory device of claim 1 , wherein the change in the pass voltage includes an offset to the pass voltage, and
wherein the change in the pass voltage is determined independently for each of a plurality of word lines included in the memory cell array.
7 . The memory device of claim 1 , wherein, after a preset time duration, the pass voltage is changed based on the recorded change in the read voltage.
8 . An operating method of a memory device configured to perform a verification operation on a memory cell array based on a pass voltage, the operating method comprising:
determining a memory block that is a target of data reading;
recording a change in a read voltage of the memory block as a recorded change in the read voltage;
and
changing the pass voltage based on the recorded change in the read voltage, comprising, when a preset number of read operations is exceeded, changing the pass voltage based on the recorded change of the read voltage.
9 . The operating method of claim 8 , wherein changing the pass voltage comprises offsetting the pass voltage based on an equation that is predetermined.
10 . The operating method of claim 9 , wherein changing the pass voltage comprises changing the pass voltage based on a preset ratio between a maximum value and a minimum value in distribution of threshold voltages.
11 . The operating method of claim 10 , wherein the preset ratio between the minimum value and the maximum value in the distribution of the threshold voltages is 1:0.93.
12 . The operating method of claim 8 , wherein changing the pass voltage comprises offsetting the pass voltage based on a preset table value.
13 . The operating method of claim 8 , wherein changing the pass voltage comprises offsetting the pass voltage independently for each of a plurality of word lines.
14 . The operating method of claim 8 , wherein changing the pass voltage comprises:
after a preset time duration has passed, changing the pass voltage based on the recorded change of the read voltage.
15 . A memory device comprising:
a memory cell array,
wherein the memory cell array comprises:
an aggressor word line on which a read operation is performed; and
a memory block including a victim word line that is adjacent to the aggressor word line, and
wherein the memory device is configured to perform a verification operation on the memory cell array based on a pass voltage signal, and configured to record a change in a read voltage with respect to the memory block as a recorded change, and
wherein the recorded change in the read voltage is a changed read level of at least one memory cell included in the memory block.
16 . The memory device of claim 15 , wherein the memory device is configured to change a pass voltage based on the recorded change in the read voltage.
17 . The memory device of claim 16 , wherein the change in the pass voltage includes an offset to the pass voltage and is based on an equation that is predetermined.