Distortion estimation and cancellation in memory devices
First Claim
1. A method for operating a memory, comprising:
- storing data in a group of analog memory cells of the memory as respective first voltage levels, selected from a set of possible values corresponding to respective possible combinations of data bits to be stored in the analog memory cells;
after storing the data, reading from the analog memory cells respective second voltage levels, which are affected by cross-coupling interference causing the second voltage levels to differ from the respective first voltage levels;
processing the second voltage levels to derive respective hard decisions, each hard decision specifying a respective combination of the data bits selected from among the possible combinations of the data bits;
calculating respective differences between the second voltage levels that were read from the analog memory cells and the respective first voltage levels corresponding to the hard decisions;
estimating cross-coupling coefficients, which quantify the cross-coupling interference among the analog memory cells, based on the differences; and
reconstructing the data stored in the group of analog memory cells from the read second voltage levels using the estimated cross-coupling coefficients.
2 Assignments
0 Petitions
Accused Products
Abstract
A method for operating a memory (28) includes storing data in a group of analog memory cells (32) of the memory as respective first voltage levels. After storing the data, second voltage levels are read from the respective analog memory cells. The second voltage levels are affected by cross-coupling interference causing the second voltage levels to differ from the respective first voltage levels. Cross-coupling coefficients, which quantify the cross-coupling interference among the analog memory cells, are estimated by processing the second voltage levels. The data stored in the group of analog memory cells is reconstructed from the read second voltage levels using the estimated cross-coupling coefficients.
459 Citations
26 Claims
-
1. A method for operating a memory, comprising:
-
storing data in a group of analog memory cells of the memory as respective first voltage levels, selected from a set of possible values corresponding to respective possible combinations of data bits to be stored in the analog memory cells; after storing the data, reading from the analog memory cells respective second voltage levels, which are affected by cross-coupling interference causing the second voltage levels to differ from the respective first voltage levels; processing the second voltage levels to derive respective hard decisions, each hard decision specifying a respective combination of the data bits selected from among the possible combinations of the data bits; calculating respective differences between the second voltage levels that were read from the analog memory cells and the respective first voltage levels corresponding to the hard decisions; estimating cross-coupling coefficients, which quantify the cross-coupling interference among the analog memory cells, based on the differences; and reconstructing the data stored in the group of analog memory cells from the read second voltage levels using the estimated cross-coupling coefficients. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method for operating a memory, comprising:
-
storing data in a group of analog memory cells of the memory as respective first voltage levels; after storing the data, reading from the analog memory cells respective second voltage levels, which are affected by cross-coupling interference causing the second voltage levels to differ from the respective first voltage levels; estimating cross-coupling coefficients, which quantify the cross-coupling interference among the analog memory cells by processing the second voltage levels; and reconstructing the data stored in the group of analog memory cells from the read second voltage levels using the estimated cross-coupling coefficients. - View Dependent Claims (12)
-
-
13. A data storage apparatus, comprising:
-
an interface, which is operative to communicate with a memory that includes a plurality of analog memory cells; and a memory signal processor (MSP), which is coupled to the interface and is arranged to store data in a group of the analog memory cells as respective first voltage levels selected from a set of possible values corresponding to respective possible combinations of data bits to be stored in the analog memory cells, to read from the analog memory cells, after storing the data, respective second voltage levels, which are affected by cross-coupling interference causing the second voltage levels to differ from the respective first voltage levels, to process the second voltage levels to derive respective hard decisions, each hard decision specifying a respective combination of the data bits selected from among the possible combinations of the data bits, to calculate respective differences between the second voltage levels that were read from the analog memory cells and the respective first voltage levels corresponding to the hard decisions, to estimate cross-coupling coefficients, which quantify the cross-coupling interference among the analog memory cells, based on the differences, and to reconstruct the data stored in the group of analog memory cells from the second voltage levels using the estimated cross-coupling coefficients. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22)
-
-
23. A data storage apparatus, comprising:
-
an interface, which is operative to communicate with a memory that includes a plurality of analog memory cells; and a memory signal processor (MSP), which is coupled to the interface and is arranged to store data in a group of the analog memory cells of the memory as respective first voltage levels, to read from the analog memory cells, after storing the data, respective second voltage levels, which are affected by cross-coupling interference causing the second voltage levels to differ from the respective first voltage levels, to estimate cross-coupling coefficients, which quantify the cross-coupling interference among the analog memory cells by processing the second voltage levels, and to reconstruct the data stored in the group of analog memory cells from the read second voltage levels using the estimated cross-coupling coefficients. - View Dependent Claims (24)
-
-
25. A data storage apparatus, comprising:
-
a memory, which comprises a plurality of analog memory cells; and a memory signal processor (MSP), which is coupled to the memory and is arranged to store data in a group of the analog memory cells as respective first voltage levels selected from a set of possible values corresponding to respective possible combinations of data bits to be stored in the analog memory cells, to read from the analog memory cells, after storing the data, respective second voltage levels, which are affected by cross-coupling interference causing the second voltage levels to differ from the respective first voltage levels, to process the second voltage levels to derive respective hard decisions, each hard decision specifying a respective combination of the data bits selected from among the possible combinations of the data bits, to calculate respective differences between the second voltage levels that were read from the analog memory cells and the respective first voltage levels corresponding to the hard decisions, to estimate cross-coupling coefficients, which quantify the cross-coupling interference among the analog memory cells, based on the differences, and to reconstruct the data stored in the group of analog memory cells from the second voltage levels using the cross-coupling coefficients.
-
-
26. A data storage apparatus, comprising:
-
a memory, which comprises a plurality of analog memory cells; and a memory signal processor (MSP), which is coupled to the memory and is arranged to store data in a group of the analog memory cells of the memory as respective first voltage levels, to read from the analog memory cells, after storing the data, respective second voltage levels, which are affected by cross-coupling interference causing the second voltage levels to differ from the respective first voltage levels, to estimate cross-coupling coefficients, which quantify the cross-coupling interference among the analog memory cells by processing the second voltage levels, and to reconstruct the data stored in the group of analog memory cells from the read second voltage levels using the estimated cross-coupling coefficients.
-
Specification