System, method and computer readable medium for generating soft information
First Claim
1. A method for generating soft information, the method comprising:
- performing by a flash memory controller a first set of read attempts of flash memory cells using a first set of read thresholds to provide first read results;
calculating, by the flash memory controller, for each flash memory cell of the flash memory cells and in response to the first read results, first cell information indicative of a first change-inducing read threshold;
performing by the flash memory controller a second set of read attempts of the flash memory cells using a second set of read thresholds to provide second read results;
wherein at least one read threshold of the second set of read thresholds substantially equals at least one read threshold of the first set of read thresholds;
calculating, by the flash memory controller, for each flash memory cell of the flash memory cells and in response to the second read results, second cell information indicative of a second change-inducing read threshold; and
generating, for each flash memory cell of the flash memory cells, soft information in response to the first cell information and the second cell information of the flash memory cell;
wherein the first set of read thresholds virtually partitions a threshold voltage distribution of the flash memory cells to multiple first voltage ranges; and
wherein the second set of read thresholds virtually partitions the threshold voltage distribution of the flash memory cells to multiple second voltage ranges.
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Abstract
A system, a method and a non-transitory computer readable medium for generating soft information. The method may include performing a first set of read attempts of flash memory cells using a first set of read thresholds to provide first read results; calculating for each flash memory cell in response to the first read results, first cell information indicative of a first change-inducing read threshold; performing a second set of read attempts of the flash memory cells using a second set of read thresholds to provide second read results, calculating for each flash memory cell in response to the second read results, second cell information indicative of a second change-inducing read threshold; and generating, for each flash memory cell soft information in response to the first cell information and the second cell information of the flash memory cell.
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Citations
22 Claims
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1. A method for generating soft information, the method comprising:
- performing by a flash memory controller a first set of read attempts of flash memory cells using a first set of read thresholds to provide first read results;
calculating, by the flash memory controller, for each flash memory cell of the flash memory cells and in response to the first read results, first cell information indicative of a first change-inducing read threshold;
performing by the flash memory controller a second set of read attempts of the flash memory cells using a second set of read thresholds to provide second read results;
wherein at least one read threshold of the second set of read thresholds substantially equals at least one read threshold of the first set of read thresholds;
calculating, by the flash memory controller, for each flash memory cell of the flash memory cells and in response to the second read results, second cell information indicative of a second change-inducing read threshold; and
generating, for each flash memory cell of the flash memory cells, soft information in response to the first cell information and the second cell information of the flash memory cell;wherein the first set of read thresholds virtually partitions a threshold voltage distribution of the flash memory cells to multiple first voltage ranges; and wherein the second set of read thresholds virtually partitions the threshold voltage distribution of the flash memory cells to multiple second voltage ranges. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
- performing by a flash memory controller a first set of read attempts of flash memory cells using a first set of read thresholds to provide first read results;
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16. A method for generating soft information, the method comprising:
- performing by a flash memory controller a first set of read attempts of flash memory cells using a first set of read thresholds to provide first read results;
calculating, by the flash memory controller, for each flash memory cell of the flash memory cells and in response to the first read results, first cell information indicative of a first change-inducing read threshold;
performing by the flash memory controller a second set of read attempts of the flash memory cells using a second set of read thresholds to provide second read results;
wherein at least one read threshold of the second set of read thresholds substantially equals at least one read threshold of the first set of read thresholds;
calculating, by the flash memory controller, for each flash memory cell of the flash memory cells and in response to the second read results, second cell information indicative of a second change-inducing read threshold;
generating, for each flash memory cell of the flash memory cells, soft information in response to the first cell information and the second cell information of the flash memory cell; anddetermining an amount of second read thresholds to be applied during the second set of read attempts based upon an outcome of an at least partial soft decoding attempt that is applied on the first read results.
- performing by a flash memory controller a first set of read attempts of flash memory cells using a first set of read thresholds to provide first read results;
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17. A method for generating soft information, the method comprising:
- performing by a flash memory controller a first set of read attempts of flash memory cells using a first set of read thresholds to provide first read results;
calculating, by the flash memory controller, for each flash memory cell of the flash memory cells and in response to the first read results, first cell information indicative of a first change-inducing read threshold;
performing by the flash memory controller a second set of read attempts of the flash memory cells using a second set of read thresholds to provide second read results;
wherein at least one read threshold of the second set of read thresholds substantially equals at least one read threshold of the first set of read thresholds;
calculating, by the flash memory controller, for each flash memory cell of the flash memory cells and in response to the second read results, second cell information indicative of a second change-inducing read threshold;
generating, for each flash memory cell of the flash memory cells, soft information in response to the first cell information and the second cell information of the flash memory cell; andperforming an additional set of read attempts of the flash memory cells using an additional set of read thresholds to provide additional read results;
wherein at least one additional read threshold of the additional set of read thresholds substantially equals at least one read thresholds of the first set of read thresholds;calculating, by the flash memory controller, for each flash memory cell and in response to the additional read results, additional cell information indicative of an additional change-inducing read threshold; and generating, for each flash memory cell, soft information in response to the first, second and additional cell information of the flash memory cell. - View Dependent Claims (18, 19)
- performing by a flash memory controller a first set of read attempts of flash memory cells using a first set of read thresholds to provide first read results;
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20. A method for generating soft information, the method comprising:
- performing by a flash memory controller a first set of read attempts of flash memory cells using a first set of read thresholds to provide first read results;
calculating, by the flash memory controller, for each flash memory cell of the flash memory cells and in response to the first read results, first cell information indicative of a first change-inducing read threshold;
performing by the flash memory controller a second set of read attempts of the flash memory cells using a second set of read thresholds to provide second read results;
wherein at least one read threshold of the second set of read thresholds substantially equals at least one read threshold of the first set of read thresholds;
calculating, by the flash memory controller, for each flash memory cell of the flash memory cells and in response to the second read results, second cell information indicative of a second change-inducing read threshold;
generating, for each flash memory cell of the flash memory cells, soft information in response to the first cell information and the second cell information of the flash memory cell; anddetermining at least one parameter of the second set of read attempts in response to a state of the flash memory cells.
- performing by a flash memory controller a first set of read attempts of flash memory cells using a first set of read thresholds to provide first read results;
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21. A non-transitory computer readable medium that stores instructions for:
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performing, by a flash memory controller, a first set of read attempts of flash memory cells using a first set of read thresholds to provide first read results; calculating, by the flash memory controller, for each flash memory cell of the flash memory cells and in response to the first read results, first cell information indicative of a first change-inducing read threshold; performing, by the flash memory controller, a second set of read attempts of the flash memory cells using a second set of read thresholds to provide second read results; wherein at least one read threshold of the second set of read thresholds substantially equals at least one read threshold of the first set of read thresholds; calculating, by the flash memory controller, for each flash memory cell of the flash memory cells and in response to the second read results, second cell information indicative of a second change-inducing read threshold; and generating, for each flash memory cell of the flash memory cells, soft information in response to the first cell information and the second cell information of the flash memory cell; wherein the first set of read thresholds virtually partitions a threshold voltage distribution of the flash memory cells to multiple first voltage ranges; and wherein the second set of read thresholds virtually partitions the threshold voltage distribution of the flash memory cells to multiple second voltage ranges.
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22. A system comprising a flash memory controller, the flash memory controller comprises:
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a read circuit that is arranged to perform; a first set of read attempts of flash memory cells using a first set of read thresholds to provide first read results; a second set of read attempts of the flash memory cells using a second set of read thresholds to provide second read results;
wherein at least one read threshold of the second set of read thresholds substantially equals at least one read threshold of the first set of read thresholds;a soft information circuit arranged to; calculate, for each flash memory cell of the flash memory cells and in response to the first read results, first cell information indicative of a first change-inducing read threshold; calculate, for each flash memory cell of the flash memory cells and in response to the second read results, second cell information indicative of a second change-inducing read threshold; and generate, for each flash memory cell of the flash memory cells, soft information in response to the first cell information and the second cell information of the flash memory cell; wherein the first set of read thresholds virtually partitions a threshold voltage distribution of the flash memory cells to multiple first voltage ranges; and wherein the second set of read thresholds virtually partitions the threshold voltage distribution of the flash memory cells to multiple second voltage ranges.
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Specification