Storage device and method including accessing a word line of a memory using parameters selected according to groups of word lines

• US 9,141,524 B2
• Filed: 09/17/2014
• Issued: 09/22/2015
• Est. Priority Date: 06/30/2009
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Sandisk Technologies Incorporated (Western Digital Corporation)
• Inventors: Alrod, Idan, Sharon, Eran
• Primary Examiner(s): Thai, Tuan
• Assistant Examiner(s): Gossage, Glenn
• Application Number:
  US14/489,024
• Publication Number:
  US 20150006800A1
• Time in Patent Office: 370 Days
• Field of Search: 711/5, 711/103, 365/51, 365/185.11, 365/185.33, 714/6.24
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1068 in sector programmable memories, e.g. flash disk G06F11/1072 takes precedence
• CPC Class Codes: G06F 12/0207 with multidimensional access, e.g. row/column, matrix
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/2022 Flash memory
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages
• CPC Class Codes: G11C 16/10 Programming or data input circuits

Abstract

A data storage device and method of accessing a word line of a memory array using values of one or more parameters based on a physical location of the word line. The method includes determining a block identifier of a physical block of a memory array that is to be accessed. The method further includes determining a word line index of a first word line within the physical block based on the block identifier and further based on a first position of the first word line within the physical block. The method further includes accessing the first word line using a first value of the first parameter.

Claims

1. A method comprising:

determining a value of a first parameter for a first word line within a first physical block of a memory;

comparing the value to a set of values including a first value of the first parameter and a second value of the first parameter;

associating the first word line with the first value in response to determining that a first difference between the value and the first value is less than a second difference between the value and the second value;

determining a block identifier of the first physical block;

determining a word line index of the first word line based on the block identifier and further based on a first position of the first word line within the first physical block, wherein the word line index is associated with a first physical location of the first word line within the memory; and

accessing the first word line using the first value of the first parameter, wherein a first group of word lines that is associated with the word line index includes the first word line and also includes a second word line within a second physical block of the memory, wherein a second group of word lines includes a third word line within the first physical block and also includes a fourth word line at the first position within the second physical block, and wherein the second group of word lines corresponds to the second value.

2. The method of claim 1, wherein the first parameter corresponds to a programming step size of a programming signal, and wherein accessing the first word line includes writing data to the first word line based on the first value of the programming step size.

3. The method of claim 1, wherein the first word line includes a first indicator corresponding to the first value of the first parameter, and wherein the first word line further includes a second indicator corresponding to a third value of a second parameter.

4. The method of claim 1, wherein the first word line includes an indicator corresponding to a first set of values, and wherein the first set of values includes the first value of the first parameter and a third value of a second parameter.

5. The method of claim 4, wherein the first set of values corresponds to a first entry of a table, and wherein the table also includes a second entry corresponding to a second set of values.

6. The method of claim 5, wherein the first word line and the second word line are associated with the first entry of the table, and wherein the third word line and the fourth word line are associated with the second entry of the table.

7. The method of claim 6, wherein associating the first word line with the first value of the first parameter includes associating the first word line with the first entry of the table.

8. The method of claim 1, wherein the first value comprises a physical location-dependent parameter value that is at least partially based on a second physical location of the first physical block within the memory and that is to be used in an error decoding operation.

9. The method of claim 1, wherein the second value comprises a time-dependent parameter value.

10. The method of claim 1, wherein the memory includes a three-dimensional array of memory cells, and wherein the memory is included in a data storage device that includes circuitry associated with operation of the three-dimensional array of memory cells.

11. A data storage device comprising:

a memory; and

a controller, wherein the controller is coupled to the memory, and wherein the controller is configured to determine a value of a first parameter for a first word line within a first physical block of the memory, to compare the value to a set of values that includes a first value of the first parameter and a second value of the first parameter, to associate the first word line with the first value in response to determining that a first difference between the value and the first value is less than a second difference between the value and the second value, to determine a block identifier of the first physical block, and to determine a word line index of the first word line based on the block identifier and further based on a first position of the first word line within the first physical block, wherein the word line index is associated with a first physical location of the first word line within the memory, wherein the controller is further configured to access the first word line using the first value of the first parameter, wherein a first group of word lines that is associated with the word line index includes the first word line and also includes a second word line within a second physical block of the memory, and wherein a second group of word lines includes a third word line within the first physical block and also includes a fourth word line at the first position within the second physical block, and wherein the second group of word lines corresponds to the second value.

12. The data storage device of claim 11, wherein the first wordline includes a first indicator corresponding to the first value of the first parameter.

13. The data storage device of claim 12, wherein the first word line includes a second indicator corresponding to a third value of a second parameter.

14. The data storage device of claim 11, wherein the first word line includes an indicator corresponding to a first set of values, and wherein the first set of values includes the first value of the first parameter and a third value of a second parameter.

15. The data storage device of claim 14, wherein the first set of values corresponds to a first entry of a table, and wherein the table also includes a second entry corresponding to a second set of values.

16. The data storage device of claim 15, wherein the first word line and the second word line are associated with the first entry of the table, and wherein the third word line and the fourth word line are associated with the second entry of the table.

17. The data storage device of claim 16, wherein the controller is further configured to associate the first word line with the first entry of the table.

18. The data storage device of claim 11, wherein the first value comprises a physical location-dependent parameter value that is at least partially based on a second physical location of the first physical block within the memory and that is to be used in an error decoding operation.

19. The data storage device of claim 11, wherein the second value is comprises a time-dependent parameter value.

20. The data storage device of claim 11, wherein the memory includes a three-dimensional array of memory cells, and further comprising circuitry associated with operation of the three-dimensional array of memory cells.