Devices and methods to conditionally send parameter values to non-volatile memory

Patent metadata

Field	Value
Publication number	US-9251891-B1
Application number	US-201414538128-A
Country	US
Kind code	B1
Filing date	Nov 11, 2014
Priority date	Nov 11, 2014
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

A data storage device that includes a controller and a non-volatile memory may perform a method that includes comparing, in the controller, first parameter values of a first group of parameter values to second parameter values of a second group of parameter values. The second parameter values of the second group of parameter values are associated with a scheduled non-volatile memory operation. The first parameter values correspond to parameter values that are in the non-volatile memory. The method includes sending, from the controller to the non-volatile memory, a parameter value of the second group in response to determining that the parameter value differs from a corresponding parameter value of the first group.

First claim

What is claimed is:

1. A method comprising:
in a data storage device including a controller and a non-volatile memory, performing:
comparing, in the controller, first parameter values of a first group of parameter values to second parameter values of a second group of parameter values, the second parameter values of the second group of parameter values associated with a scheduled non-volatile memory operation, the first parameter values corresponding to parameter values that are at the non-volatile memory; and
sending, from the controller to the non-volatile memory, a parameter value of the second group in response to determining that the parameter value differs from a corresponding parameter value of the first group.

2. The method of claim 1 , wherein the controller accesses the first group of parameter values from a controller memory and wherein the first group of parameter values matches parameter values that are stored in a control register of the non-volatile memory.

3. The method of claim 2 , further comprising updating the controller memory to store the second group of parameter values, wherein the second group of parameter values duplicates contents of the control register of the non-volatile memory after sending the parameter value of the second group to the control register of the non-volatile memory.

4. The method of claim 1 , further comprising, prior to comparing the second parameter values to the first parameter values, comparing information related to the scheduled non-volatile memory operation to information related to a most recently initiated non-volatile memory operation, and wherein the second parameter values are compared to the first parameter values in response to the information related to the scheduled non-volatile memory operation differing from the information related to the most recently initiated non-volatile memory operation.

5. The method of claim 4 , wherein comparing the information related to the scheduled non-volatile memory operation to the information related to the most recently initiated non-volatile memory operation includes comparing a program/read mode, a multi-bits-per-cell (MLC)/single bit-per-cell (SLC) mode, and a trim parameter value of the scheduled non-volatile memory operation to a program/read mode, a MLC/SLC mode, and a trim parameter value of the most recently initiated non-volatile memory operation.

6. A method comprising:
in a data storage device including a controller and a non-volatile memory, performing in response to receiving a multi-bit-per-cell (MLC) write operation to be performed at the non-volatile memory:
determining whether a next operation is a single bit-per-cell (SLC) write operation, wherein the next operation follows the MLC write operation according to a schedule of operations to be performed at the non-volatile memory;
selecting a first group of parameter values if the next operation is a SLC write operation and selecting a second group of parameter values if the next operation is not a SLC write operation;
sending parameter values of the selected one of the first group and the second group to a control register in the non-volatile memory; and
initiating the MLC write operation,
wherein processing of the MLC write operation at the non-volatile memory is suspended to enable the next operation to be performed at the non-volatile memory prior to completion of the MLC write operation, and wherein the parameter values remain in the control register in the non-volatile memory until the MLC write operation is completed.

7. The method of claim 6 , wherein the first group of parameter values includes parameter values corresponding to the MLC write operation and parameter values corresponding to the SLC write operation, and wherein the second group of parameter values includes the parameter values corresponding to the MLC write operation and parameter values corresponding to read operations.

8. The method of claim 7 , wherein the parameter values corresponding to read operations include first offset values to convert MLC parameter values to SLC read parameter values and wherein the parameter values corresponding to the SLC write operation include second offset values to convert the MLC parameter values to SLC write parameter values.

9. The method of claim 6 , wherein the controller determines an MLC trim index indicating a set of MLC trim parameters and an SLC trim index indicating a set of SLC trim parameter, wherein the controller determines a set of MLC-to-SLC trim-based conversion parameters, and wherein the first group of parameter values and the second group of parameter values include the set of MLC-to-SLC trim-based conversion parameters.

10. The method of claim 9 , wherein the controller updates values of the set of MLC-to-SLC trim-based conversion parameters in response to a change in one or both of the MLC trim index or the SLC trim index, and wherein the controller stores the updated values of the MLC-to-SLC trim-based conversion parameters in a controller memory.

11. The method of claim 9 , wherein the set of MLC-to-SLC trim-based conversion parameters corresponds to current values of the MLC trim index and the SLC trim index and is used during MLC program suspend operations to read SLC data having a current version of the SLC trim index or having a prior version of multiple prior versions of the SLC trim index.

12. The method of claim 6 , wherein prior to sending the parameter values of the selected one of the first group and the second group to the control register in the non-volatile memory, the controller compares the parameter values of the selected one of the first group and the second group to parameter values in a controller memory, wherein the parameter values in the controller memory duplicate parameter values that are in the control register in the non-volatile memory, and the controller selects which parameter values to send to the control register in the non-volatile memory based on the comparison.

13. A data storage device comprising:
a non-volatile memory; and
a controller coupled to the non-volatile memory, wherein the controller includes:
a logic unit configured to compare a first group of parameter values stored at a controller memory to a second group of parameter values associated with a scheduled memory operation, wherein the first group of parameter values corresponds to parameter values that are in the non-volatile memory; and
an interfacing unit configured to send a parameter value of the second group to the non-volatile memory in response to an indication from the logic unit that the parameter value differs from a corresponding parameter value of the first group.

14. The data storage device of claim 13 , wherein the controller memory comprises a memory that is accessible to the controller and that is configured to store multiple groups of parameter values including the first group of parameter values and the second group of parameter values.

15. The data storage device of claim 13 , wherein the controller includes a management unit configured to maintain, in the controller memory, a copy of parameter values that are stored in the control register of the non-volatile memory and to update contents of the controller memory to indicate changes to parameter values in the control register of the non-volatile memory.

16. The data storage device of claim 13 , wherein the controller includes a non-volatile memory operation comparator configured to compare information related to the scheduled memory operation to information related to a most recently initiated memory operation, and wherein the controller i

Assignees

• Sandisk Technologies Inc

Inventors

• Hu Ken Jianhui
• Yang Nian Niles
• Khurana Bhuvan
• Gavens Lee M
• Tanpairoj Kulachet

Classifications

• G11C16/10

  Programming or data input circuits · CPC title

• G11C16/26

  Sensing or reading circuits; Data output circuits · CPC title

• G11C11/5628

  Programming or writing circuits; Data input circuits · CPC title

• G11C11/5642 Primary

  Sensing or reading circuits; Data output circuits · CPC title

• G11C2211/5641

  Multilevel memory having cells with different number of storage levels · CPC title