Write data for bin resynchronization after power loss

Patent metadata

Field	Value
Publication number	US-11301382-B2
Application number	US-202016948774-A
Country	US
Kind code	B2
Filing date	Sep 30, 2020
Priority date	Aug 13, 2020
Publication date	Apr 12, 2022
Grant date	Apr 12, 2022

Abstract

A system includes a memory device and a processing device, operatively coupled to the memory device. The processing device is to perform operations including detecting a voltage of a power source for the memory device has dropped below a threshold voltage indicative of an imminent power loss and writing data to the memory device in response to the detecting. The operations further include measuring a characteristic of the data in response to detecting a power on of the memory device; determining an estimated amount of time for which the memory device was powered off based on results of the measuring; and in response to the estimated amount of time satisfying a first threshold criterion, updating a value for a temporal voltage shift of a block family of programmed data based on the estimated amount of time.

First claim

What is claimed is:

1. A system comprising:
a memory device; and
a processing device, operatively coupled to the memory device, the processing device to perform operations comprising:
detecting a voltage of a power source for the memory device has dropped below a threshold voltage indicative of an imminent power loss;
writing data to the memory device in response to the detecting;
measuring a characteristic of the data in response to detecting a power on of the memory device;
determining an estimated amount of time for which the memory device was powered off based on results of the measuring; and
in response to the estimated amount of time satisfying a first threshold criterion, updating a value for a temporal voltage shift of a block family of programmed data based on the estimated amount of time.

2. The system of claim 1 , wherein measuring the characteristic comprises measuring one of temporal voltage shift of the data or a read bit error rate of the data.

3. The system of claim 1 , wherein the data is of a predetermined pattern, and the operations further comprise, in conjunction with the writing, storing a location of the data.

4. The system of claim 1 , wherein the operations further comprise:
resynchronizing assignment of a threshold voltage offset bin to the block family based on the updated value for temporal voltage shift of the block family; and
transitioning to execution of host memory commands received from a host system.

5. The system of claim 1 , wherein the measuring comprises measuring a data state metric associated with one or more memory cell of the data, and the operations further comprise:
comparing a level of the data state metric to a temporal voltage shift function to determine the estimated amount of time; and
incrementing a value of a timer, restored from the memory device, based on the estimated amount of time.

6. The system of claim 1 , wherein the operations further comprise:
determining that the estimated amount of time does not satisfy the first threshold criterion; and
transitioning directly to execution of host memory commands received from a host system.

7. The system of claim 1 , wherein the operations further comprise:
determining that the estimated amount of time satisfies a second threshold criterion that is greater than the first threshold criterion;
tuning an algorithm, which is used to measure temporal voltage shift of block families, in order to accurately measure aged programmed pages based on the estimated amount of time; and
transitioning to execution of host memory commands received from a host system.

8. The system of claim 1 , further comprising:
the power source to power the memory device; and
one or more capacitors coupled to the power source to extend a period of time from the detecting to a loss of power of the memory device.

9. A method comprising:
detecting, by a processing device of a memory sub-system, a voltage of a power source for a memory device has dropped below a threshold voltage indicative of an imminent power loss;
writing, by the processing device, data of a predetermined pattern to the memory device in response to the detecting;
in response to detecting a power on of the memory device:
reading a time value of a low power clock;
measuring a temporal voltage shift of the data; and
determining, based on the time value and the temporal voltage shift, an estimated amount of time the memory device was powered off; and

updating, by the processing device in response to the estimated amount of time satisfying a first threshold criterion, a value for temporal voltage shift of a block family of programmed data based on the estimated amount of time.

10. The method of claim 9 , wherein updating the value for the temporal voltage shift of the block family further comprises updating bin pointers of a vector in a block family table indexed to the block family from a superblock table.

11. The method of claim 9 , further comprising:
resynchronizing assignment of a threshold voltage offset bin to the block family based on the updated value of the temporal voltage shift for the block family; and
transitioning to execution of host memory commands received from a host system.

12. The method of claim 9 , wherein the measuring comprises measuring a data state metric associated with one or more memory cell of the data, the method further comprising:
comparing a level of the data state metric to a temporal voltage shift function to determine the estimated amount of time; and
incrementing a value of a timer, restored from the memory device, based on the estimated amount of time.

13. The method of claim 9 , further comprising:
determining that the estimated amount of time does not satisfy the first threshold criterion; and
transitioning directly to execution of host memory commands received from a host system.

14. The method of claim 9 , further comprising:
determining that the estimated amount of time satisfies a second threshold criterion that is greater than the first threshold criterion;
tuning an algorithm, which is used to measure temporal voltage shift of block families, in order to accurately measure aged programmed pages; and
transitioning to execution of host memory commands received from a host system.

15. A method comprising:
detecting, by a processing device of a memory sub-system, a voltage of a power source for a memory device has dropped below a threshold voltage indicative of an imminent power loss;
writing, by the processing device, data to the memory device in response to the detecting;
measuring a characteristic of the data, by the processing device, in response to detecting a power on of the memory device;
determining, by the processing device based on results of the measuring, an estimated amount of time the memory device was powered off; and
updating, by the processing device in response to the estimated amount of time satisfying a first threshold criterion, a value for a temporal voltage shift of each block family of a plurality of block families of programmed data based on the estimated amount of time.

16. The method of claim 15 , wherein the measuring the characteristic comprises measuring one of temporal voltage shift of the data or a read bit error rate of the data.

17. The method of claim 15 , further comprising:
resynchronizing assignment of a threshold voltage offset bin to at least some of the plurality of block families based on the updated value of the temporal voltage shift for each block family of the plurality of block families; and
transitioning to execution of host memory command received from a host system.

18. The method of claim 15 , wherein the measuring comprises measuring a data state metric associated with one or more memory cell of the data, the method further comprising:
comparing a level of the data state metric to a temporal voltage shift function to determine the estimated amount of time; and
incrementing a value of a timer, restored from the memory device, based on the estimated amount of time.

19. The method of claim 15 , further comprising:
determining that the estimated amount of time does not satisfy the first threshold criterion; and
transitioning directly to execution of host memory commands received from a host system.

20. The method of claim 15 , further comprising:
determining that the estimated amount of time satisfies a second threshold criterion that is greater than the first threshold criterion;
tuning an algorithm, which is used to me

Assignees

• Micron Technology Inc

Inventors

• Sheperek Michael
• Liikanen Bruce A
• Kientz Steven Michael

Classifications

• G06F2201/81

  Threshold · CPC title

• G06F11/1441

  Resetting or repowering · CPC title

• G06F1/305

  in the event of power-supply fluctuations · CPC title

• G06F1/30

  Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations (for resetting only G06F1/24) · CPC title

• G01R19/16552

  in I.C. power supplies · CPC title