Data storage device including nonvolatile memory device and operating method thereof

Patent metadata

Field	Value
Publication number	US-10133665-B2
Application number	US-201715701978-A
Country	US
Kind code	B2
Filing date	Sep 12, 2017
Priority date	Oct 15, 2014
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

A method of operating a data storage device includes programming non-fully programmed memory blocks at a point in time when a reference time elapses from a point in time when each of the memory blocks is physically erased, acquiring a first interval and a second interval, calculating a disturb index based on the first interval and the second interval, selecting a victim block for garbage collection based on the disturb index, and copying valid page data of the victim block into a free block. The first interval is defined by a point in time when each of the memory blocks is physically erased and a point in time when each of the memory blocks is fully programmed. The second interval is an interval during which a fully programmed state is maintained after a point in time when each of the memory blocks is fully programmed.

First claim

What is claimed is:

1. A method of operating a data storage device, the data storage device including a nonvolatile memory device and a memory controller configured to control a garbage collection operation of the nonvolatile memory device, the nonvolatile memory device including a plurality of memory blocks on a substrate, each of the plurality of memory blocks including a plurality of three dimensional memory cell strings on the substrate formed in a direction perpendicular to the substrate, and the memory controller including a disturb manager, the method comprising:
performing a dummy closing operation on N memory blocks among the plurality of memory blocks, N being an integer greater than one and less than a number of the plurality of memory blocks, each of the N memory blocks being not fully programmed before the performing the dummy closing operation;
storing an interval and a threshold time for each of the N memory blocks in the disturb manager of the memory controller, the interval being an elapsed time from the dummy closing operation of a corresponding memory block among the N memory blocks, and the threshold time being a time delay that is minimally required between the dummy closing operation and the garbage collection operation of the corresponding memory block;
selecting a victim block among the N memory blocks based on the intervals of the N memory blocks, the selecting the victim block including selecting a particular memory block among the N memory blocks as the victim block based on the interval of the particular memory block being equal to or longer than the threshold time; and
copying valid page data of the victim block into a free block among the plurality of memory blocks.

2. The method of claim 1 , wherein
the performing the dummy closing operation includes performing the dummy closing operation on a memory block that is not fully programmed with user data and thus includes at least one physically erased page, and
the performing the dummy closing operation includes completely programming the memory block with user data and dummy data without leaving any physically erased page in the memory block.

3. The method of claim 1 , wherein, in response to the N memory blocks including several memory blocks having intervals exceeding the threshold time, the selecting the victim block includes selecting a memory block having a largest number of invalid pages among the several memory blocks as the victim block.

4. The method of claim 1 , wherein the performing the dummy closing operation includes performing the dummy closing operation in response to a sudden power-off or in response to a power off reset event that is issued.

5. The method of claim 4 , wherein the performing the dummy closing operation includes performing the dummy closing operation after recovery of the sudden power-off or the power off reset event.

6. A method of operating a data storage device, the data storage device including a nonvolatile memory device and a memory controller configured to control a garbage collection operation of the nonvolatile memory device, the nonvolatile memory device including a plurality of memory blocks on a substrate, and each of the plurality of memory blocks including a plurality of three dimensional memory cell strings on the substrate formed in a direction perpendicular to the substrate, and the memory controller including a disturb manager, the method comprising:
performing a dummy closing operation on N memory blocks among the plurality of memory blocks, N being an integer greater than one and less than a number of the plurality of memory blocks, each of the N memory blocks being not fully programmed before the performing the dummy closing operation, and the dummy closing operation including programming each of the N memory blocks with dummy data so that each of the N memory blocks is fully programmed with at least one of user data or dummy data;
storing a first interval, a second interval, a first threshold time and a second threshold time for each of the N memory blocks in the disturb manager,
the first interval being an elapsed time from a physical erase operation to the dummy closing operation of a corresponding memory block among the N memory blocks,
the second interval being an elapsed time from the dummy closing operation of the corresponding memory block,
the first threshold time being a time delay that is minimally required between the physical erase operation and the dummy closing operation of the corresponding memory block, and
the second threshold time being a time delay that is minimally required between the dummy closing operation and the garbage collection operation on the corresponding memory block;

selecting a victim block among the N memory blocks based on the second intervals of the N memory blocks, the selecting the victim block including selecting a particular memory block among the N memory blocks as the victim block in response to the second interval of the particular memory block being equal to or longer than the second threshold time; and
copying valid page data of the victim block into a free block among the plurality of memory blocks.

7. The method of claim 6 , wherein
the performing the dummy closing operation includes performing the dummy closing operation on a memory block that is not fully programmed with user data and thus includes at least one physically erased page, and
the performing the dummy closing operation includes completely programming the memory block with user data and dummy data without leaving any physically erased page in the memory block.

8. The method of claim 6 , wherein the performing the dummy closing operation includes performing the dummy closing operation on a memory block in response to the first interval exceeding the first threshold time.

9. The method of claim 8 , further comprising:
determining whether to perform the dummy closing operation on the memory block in response to comparing the first interval stored in the disturb manager with the first threshold time.

10. The method of claim 6 , wherein, in response to the N memory blocks including several memory blocks having second intervals that exceed the second threshold time, the selecting the victim block includes selecting a memory block having a largest number of invalid pages among the several memory blocks as the victim block.

11. The method of claim 6 , wherein the performing the dummy closing operation includes performing the dummy closing operation in response to a sudden power-off or in response to a power off reset event that is issued.

12. The method of claim 11 , wherein the performing the dummy closing operation includes performing the dummy closing operation after recovery of the sudden power-off or the power off reset event.

13. The method of claim 6 , comprising:
erasing the victim block after the copying valid page data of the victim block into the free block.

14. A data storage device, the data storage device comprising:
a nonvolatile memory device, the nonvolatile memory device including a plurality of memory blocks on a substrate, each of the plurality of memory blocks including a plurality of three dimensional memory cell strings on the substrate formed in a direction perpendicular to the substrate; and
a memory controller coupled to the nonvolatile memory device,
the memory controller including a disturb manager,
the memory controller being configured to perform a dummy closing operation on N memory blocks among the plurality of memory blocks, N being an integer greater than one and less than a number of the plurality of memory blocks, each of the N memory blocks being not

Assignees

• Moon Sangkwon
• Lee Seung Yeon
• Lee Heewon
• Doh In Hwan
• Kang Namwook
• Samsung Electronics Co Ltd

Inventors

• Moon Sangkwon
• Lee Seung-Yeon
• Lee Heewon
• Doh In Hwan
• Kang Namwook

Classifications

• G06F3/0614

  Improving the reliability of storage systems · CPC title

• G06F12/0253

  Garbage collection, i.e. reclamation of unreferenced memory · CPC title

• G06F2212/1032

  Reliability improvement, data loss prevention, degraded operation etc · CPC title

• G06F2212/1016

  Performance improvement · CPC title

• G06F2212/7205

  Cleaning, compaction, garbage collection, erase control · CPC title