VECTORIZED PROCESSING LEVEL CALIBRATION IN A MEMORY COMPONENT

• US 20200133528A1
• Filed: 10/31/2018
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Sheperek, Michael, Koudele, Larry J.
• Granted Patent: US 10,761,749 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0629 Configuration or reconfiguration of storage systems
• CPC Class Codes: G06F 3/0655 Vertical data movement, i.e. input-output transfer; data movement between one or more hosts and one or more storage devices
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]
• CPC Class Codes: G11C 11/5642 Sensing or reading circuits; Data output circuits
• CPC Class Codes: G11C 29/021 in voltage or current generators
• CPC Class Codes: G11C 29/028 with adaption or trimming of parameters
• CPC Class Codes: G11C 29/16 using microprogrammed units, e.g. state machines
• CPC Class Codes: G11C 29/52 Protection of memory contents; Detection of errors in memory contents

Abstract

First and second vectors each respectively having first and second magnitudes and first and second phase angles relative to a reference axis are determined by a processing device based on a set of error values corresponding a current processing level for processing data in memory operations on memory cells of a memory component. An estimated processing level offset is generated based on a comparison between at least one of a difference between the first magnitude and the second magnitude or a difference between the first phase angle and the second phase angle. An updated processing level is generated based on the estimated processing level offset, and the updated processing level replaces the current processing level.

Claims

1. A system, comprising:

a memory component including a plurality of memory cells; and

a processing device, operatively coupled to the memory device, to;

determine a first vector having a first magnitude and a first phase angle relative to a reference axis, the first vector corresponding to a difference between an error value for a current processing level for processing data and an error value for a first offset processing level,

determine a second vector having a second magnitude and a second phase angle relative to the reference axis, the second vector corresponding to a difference between the error value for the current processing level and an error value for a second offset processing level, wherein the first offset processing level is different from the second offset processing level,

generate an estimated processing level offset based on at least one of a difference between the first magnitude and the second magnitude or a difference between the first phase angle and the second phase angle, and

generate an updated processing level based on the estimated processing level offset, the updated processing level to replace the current processing level,

wherein the current processing level and the updated processing level relate to processing the data for a subset of the plurality of memory cells.

2. The system of claim 1, wherein the generation of the estimated processing level offset includes estimating a shift in a process level value of the current processing level based on a difference between at least one component of the first magnitude or at least one component of the second magnitude.

3. The system of claim 2, wherein the shift in the process level value is further based on a characteristic of a valley distribution associated with the current processing level.

4. The system of claim 2, wherein the determination of the first vector, the determination of the second vector, the generation of the estimated processing level offset, the generation of the updated processing level, and replacement of the current processing level with the updated processing level is processed iteratively until at least one of,

the difference between the first magnitude and the second magnitude is within a first predetermined value,

the difference between the first phase and a negative of the second phase with respect to the reference axis is within a second predetermined value, wherein the reference axis corresponds to the updated processing level, or

a dither condition is reached for the updated processing level.

5. The system of claim 4, wherein the updated processing level is an output of a convergence function with the estimated processing level offset as an input to the convergence function, the convergence function determining a rate of convergence for the iterative processing, and

wherein a gain for the convergence function is dependent on a type of memory cell in the subset of the plurality of memory cells.

6. The system of claim 1, wherein the plurality of memory cells is arranged in a plurality of memory pages, and wherein the subset comprises one of the plurality of memory pages.

7. The system of claim 1, wherein the current processing level, the first offset processing level, the second offset processing level, and the updated processing level are threshold voltages corresponding to read levels.

8. A method, comprising:

sampling center, first, and second error values for a current processing level, a first offset processing level, and a second offset processing level, respectively, wherein the first offset processing level is different from the second offset processing level;

determining a first vector having a first magnitude and a first phase angle relative to a reference axis, the first vector corresponding to a difference between the center and first error values;

determining a second vector having a second magnitude and a second phase angle relative to the reference axis, the second vector corresponding to a difference between the center and second error values;

generating an estimated processing level offset based on at least one of a difference between the first magnitude and the second magnitude or a difference between the first phase angle and the second phase angle; and

generating an updated processing level based on the estimated processing level offset, the updated processing level to replace the current processing level,

wherein the current processing level and the updated processing level relate to processing data corresponding to a subset of a plurality of memory cells of a memory component.

9. The method of claim 8, wherein the generating of the estimated processing level offset includes estimating a shift in a process level value of the current processing level based on a difference between at least one component of the first magnitude or at least one component of the second magnitude.

10. The method of claim 9, wherein the shift in the process level value is further based on a characteristic of a valley distribution associated with the current processing level.

11. The method of claim 9, further comprising:

processing iteratively the determining of the first vector, the determining of the second vector, the generating of the estimated processing level offset, the generating of the updated processing level, and replacing of the current processing level with the updated processing level until at least one of,

the difference between the first magnitude and the second magnitude is within a first predetermined value,

the difference between the first phase and a negative of the second phase with respect to the reference axis is within a second predetermined value, wherein the reference axis corresponds to the updated processing level, or

a dither condition is reached for the updated processing level.

12. The method of claim 11, further comprising:

determining a rate of convergence for the iterative generation based on a type of memory cell in the subset of the plurality of memory cells.

13. The method of claim 9, wherein the plurality of memory cells is arranged in a plurality of memory pages, and

wherein the subset comprises one of the plurality of memory pages.

14. The method of claim 8, wherein the current processing level, the first offset processing level, the second offset processing level, and the updated processing level are threshold voltages corresponding to read levels.

15. A non-transitory computer-readable storage medium comprising instructions that, when executed by a processing device, cause the processing device to:

determine a first vector having a first magnitude and a first phase angle relative to a reference axis, the first vector corresponding to a difference between an error value for a current processing level for processing data and an error value for a first offset processing level;

determine a second vector having a second magnitude and a second phase angle relative to a reference axis, the second vector corresponding to a difference between the error value for the current processing level and an error value for a second offset processing level for processing the data, wherein the first offset processing level is different from the second offset processing level;

generate an estimated processing level offset based on at least one of a difference between the first magnitude and the second magnitude or a difference between the first phase angle and the second phase angle; and

generate an updated processing level based on the estimated processing level offset, the updated processing level to replace the current processing level,

wherein the current processing level and the updated processing level relate to processing the data corresponding to a subset of a plurality of memory cells of a memory component.

16. The non-transitory computer-readable storage medium of claim 15, wherein the generating of the estimated processing level offset includes estimating a shift in a process level value of the current processing level based on a difference between at least one component of the first magnitude or at least one component of the second magnitude.

17. The non-transitory computer-readable storage medium of claim 15, wherein the shift in the process level value is further based on a characteristic of a valley distribution associated with the current processing level.

18. The non-transitory computer-readable storage medium of claim 15, further causing the processing device to:

processing iteratively the determining of the first vector, the determining of the second vector, the generating of the estimated processing level offset, the generating of the updated processing level, and replacing of the current processing level with the updated processing level until at least one of,

the difference between the first magnitude and the second magnitude is within a first predetermined value,

the difference between the first phase and a negative of the second phase with respect to the reference axis is within a second predetermined value, wherein the reference axis corresponds to the updated processing level, or

a dither condition is reached for the updated processing level.

19. The non-transitory computer-readable storage medium of claim 18, further causing the processing device to:

determine a rate of convergence for the iterative generation based on a type of memory cell in the subset of the plurality of memory cells.

20. The non-transitory computer-readable storage medium of claim 15, wherein the current processing level, the first offset processing level, the second offset processing level, and the updated processing level are all read level voltages.