Method of operating storage controller, storage device, and method of operating storage device to perform copy-block operation based on number of corrected bits
A method includes selecting, by a storage controller, a representative page of a first group stored in a first area included in a non-volatile memory device; receiving, by the storage controller, the representative page from the non-volatile memory device; performing, by the storage controller, an error detection operation of determining a number of error bits for the representative page; based on determining that the number of error bits of the representative page exceeds a threshold value, performing an external copy-back operation, by the storage controller, for each page of the first group to a second area included in the non-volatile memory device; and based on determining that the number of error bits of the representative page is less than or equal to the threshold value, performing an internal copy-back operation, by the storage controller, for each page of the first group to the second area.
1 . A method of operating a storage controller and a storage device comprising a non-volatile memory device, the method comprising:
selecting, by the storage controller, a representative page of a first group of pages stored in a first area included in the non-volatile memory device;
receiving, by the storage controller, the representative page from the non-volatile memory device;
performing, by the storage controller, an error detection operation of determining a number of error bits for the representative page;
based on determining that the number of error bits of the representative page exceeds a threshold value, performing an external copy-back operation, by the storage controller, for each of a plurality of pages of the first group of pages to a second area included in the non-volatile memory device, the second area located in a different portion of the non-volatile memory device than the first area; and
based on determining that the number of error bits of the representative page is less than or equal to the threshold value, performing an internal copy-back operation, by the storage controller, for each of the plurality of pages of the first group of pages to the second area,
wherein the selecting of the representative page of the first group of pages comprises selecting a page from the first group of pages that is programmed before the other pages in the first group of pages.
2 . The method of claim 1 , wherein the first area comprises a first set of memory cells configured to store n bits per cell, wherein the second area comprises a second set of memory cells configured to store m bits per cell, wherein n is a positive integer, and wherein m is a positive integer greater than n.
3 . The method of claim 1 , wherein the external copy-back operation comprises:
transmitting, by the storage controller, a read command for other pages in the first group of pages to the non-volatile memory device;
outputting, by the non-volatile memory device, the other pages to the storage controller;
performing, by the storage controller, an error correction operation on the other pages to generate a corrected page; and
outputting, by the storage controller, a program command and the corrected page to the non-volatile memory device.
4 . The method of claim 1 , wherein the internal copy-back operation comprises transmitting a copy-back command by the storage controller to the non-volatile memory device.
5 . The method of claim 4 , wherein the internal copy-back operation further comprises:
in response to the copy-back command,
(i) sensing, by the non-volatile memory device, a page stored in the first area, and
(ii) storing, by the non-volatile memory device, the sensed page in a page buffer circuit, in response to the copy-back command; and
programming, by the non-volatile memory device, the sensed page stored in the page buffer circuit into the second area.
6 . The method of claim 1 , further comprising comparing the number of error bits with the threshold value.
7 . The method of claim 1 , wherein determining a number of error bits for remaining pages of the first group, excluding the representative page, is skipped.
8 . The method of claim 1 , further comprising:
performing a read voltage search operation for the representative page; and
determining one or more optimal read voltage levels based on a result of the read voltage search operation.
9 . The method of claim 8 , wherein
the performing the external copy-back operation further comprises repeating the external copy-back operation based on the one or more optimal read voltage levels applied to the representative page, and
the performing the internal copy-back operation comprises repeating the internal copy-back operation based on the one or more optimal read voltage levels applied to the representative page.
10 . A storage device comprising:
a non-volatile memory device comprising a first area and a second area located in a different portion of the non-volatile memory device than the first area; and
a storage controller configured to perform a migration operation in which pages of a first group of pages stored in the first area are moved to the second area, wherein
the storage controller, to perform the migration operation, is configured to:
select a representative page of the first group of pages,
perform an error detection operation that determines a number of error bits of the representative page of the first group of pages,
based on a determination that the number of error bits of the representative page exceeds a threshold value, perform an external copy-back operation for each of a plurality of pages of the first group of pages to the second area, and
based on a determination that the number of error bits of the representative page is less than or equal to the threshold value, perform an internal copy-back operation for each of the plurality of pages of the first group of pages,
wherein the selection of the representative page comprises the storage controller configured to select a page from the first group of pages that is programmed before the other pages in the first group of pages.
11 . The storage device of claim 10 , wherein the external copy-back operation further comprises:
the storage controller configured to transmit a read command for other pages in the first group of pages to the non-volatile memory device,
the non-volatile memory device configured to output the other pages to the storage controller,
the storage controller configured to perform an error correction operation on the other pages to generate a corrected page, and
the non-volatile memory device configured to receive a program command and the corrected page from the storage controller.
12 . The storage device of claim 10 , wherein the internal copy-back operation further comprises:
the storage controller configured to transmit a copy-back command to the non-volatile memory device,
in response to the copy-back command, the non-volatile memory device configured to: (i) sense a page stored in the first area and (ii) store the sensed page in a page buffer circuit, and
the non-volatile memory device configured to program the page stored in the page buffer circuit into the second area.
13 . The storage device of claim 10 , wherein determining a number of error bits for remaining pages of the first group, excluding the representative page, is skipped.
14 . The storage device of claim 10 , wherein the storage controller is configured to perform a read voltage search operation for the representative page and determine one or more optimal read voltage levels based on a result of the read voltage search operation.
15 . The storage device of claim 14 , wherein the storage controller is configured to repeat the internal copy-back operation and repeat the external copy-back operation based on the one or more optimal read voltage levels applied to the representative page.
16 . A method of operating a storage controller configured to control a non-volatile memory device comprising a first area and a second area located in a different portion of the non-volatile memory device than the first area, the method comprising:
selecting a representative page of a first group of pages stored in the first area included in the non-volatile memory device;
receiving the representative page from the non-volatile memory device;
performing an error detection operation of determining a number of error bits for the representative page;
based on determining that the number of error bits of the representative page exceeds a threshold value, performing an external copy-back operation for each of a plurality of pages of the first group of pages to the second area included in the non-volatile memory device; and
based on determining that the number of error bits of the representative page is less than or equal to the threshold value, performing an internal copy-back operation for each of the plurality of pages of the first group of pages,
wherein the selecting of the representative page of the first group of pages comprises selecting a page from the first group of pages that is programmed before the other pages in the first group of pages.
17 . The method of claim 16 , wherein the external copy-back operation comprises:
transmitting a read command for other pages in the first group of pages to the non-volatile memory device;
receiving the other pages from the non-volatile memory device;
performing an error correction operation on the other pages to generate a corrected page; and
outputting a program command and the corrected page to the non-volatile memory device.
18 . The method of claim 16 , wherein the internal copy-back operation comprises transmitting a copy-back command to the non-volatile memory device.
19 . The method of claim 16 , wherein determining a number of error bits for remaining pages of the first group, excluding the representative page, is skipped.
20 . The method of claim 16 , further comprising:
performing a read voltage search operation for the representative page; and
determining one or more optimal read voltage levels based on a result of the read voltage search operation.