Rank-modulation rewriting codes for flash memories

A computer method of operating a memory device, the method comprising:

• receiving a new data set m for a rank to store in the memory device wherein the memory device comprises a plurality of cells;
• reading a current state of the plurality of cells within the plurality of cells are arranged according to a rank modulation scheme and the plurality of cells are used to store the new data set;
• determine a new multi-permutation to be written to the plurality of cells representing the received data set m determined in accordance with a predetermined cost;
• write the new multi-permutation on to memory.

A computer method of operating a memory device, the method comprising:

• receiving a data value composing a plurality of data sets wherein each data set is a set of values representing a rank in a plurality of ranks and repeating for the data sets in the data value, operations comprising:
• receiving a new data set for a rank of the plurality of ranks to be stored in the memory device wherein the memory device comprises a plurality of cells;
• reading a current state of candidate cells within the plurality of cells wherein candidate cells are used to store the new data set;
• creating a binary representation, of the plurality of cells used to store the new data set;
• using a WOM code to combine the binary representation with the new data set to create a binary WOM vector;
• modifying the binary WOM vector to equal quantities of 1's and 0's within the candidate cells creating a new data vector;
• writing the new data vector to the candidate cells.

A computer method of operating a memory device, the method comprising:

• reading a plurality of cells and determining a multi-permutation stored in the plurality of cells;
• identifying a group of cells in the plurality of cells, contained within each rank of a plurality of ranks;
• for each rank, performing the steps of:
• reading a new data vector from the rank;
• modifying the new data vector to recreate a binary WOM vector;
• using a WOM code on the binary WOM vector to separate a binary representation from a data set.

A memory controller comprising:

• an interface that receives a new data set for a rank of a plurality of ranks to be stored in a memory comprising a plurality of cells;
• a processor configured to perform operations of:
• reading a current state of candidate cells within the plurality of cells wherein candidate cells are used to store the new data set;
• creating a binary representation of the plurality of cells used to store the new data set;
• using a WOM code to combine the binary representation with the new data set to create a binary WOM vector;
• modifying the binary WOM vector to equal quantities of 1's and 0's within the candidate cells creating a new data vector;
• writing the new data vector to the candidate cells.

A memory controller comprising:

• an interface that receives a new data set m for a rank to be stored in a memory device wherein the memory device comprises a plurality of cells;
• a processor configured to perform operations of:
• reading a current state of the plurality of cells within the plurality of cells are arranged according to a rank modulation scheme and the plurality of cells are used to store the new data set;
• determine a new multi-permutation to be written to the plurality of cells representing the received data set m determined in accordance with a predetermined cost;
• write the new multi-permutation to memory.

A memory controller comprising:

• an interface that receives a data value comprising a plurality of data sets wherein each data set is a set of values representing a rank in a plurality of ranks;
• a processor configured to perform operations repeated for the data sets in the data value, the operations comprising:
• receiving a new data set for a rank of the plurality of ranks to be stored in the memory device wherein the memory device comprises a plurality of cells;
• reading a current state of candidate cells within the plurality of cells wherein candidate cells are used to store the new data set;
• creating a binary representation of the plurality of cells used to store the new data set;
• using a WOM code to combine the binary representation with the new data set to create a binary WOM vector;
• modifying the binary WOM vector to equal quantities of 1's and 0's within the candidate cells creating a new data vector;
• writing the new data vector to the candidate cells.

A memory controller comprising:

• an interface that provides access to a plurality of cells in a memory device;
• a processor that accesses the plurality of cells through the interface and reads the plurality of cells and performs operations comprising determining a multi-permutation stored in the plurality of cells, and identifying a group of cells in the plurality of cells contained within each rank of a plurality of ranks and, for each rank, performing the operations of:
• reading a new data vector from the rank;
• modifying the new data vector to recreate a binary WOM vector;
• using a WOM code on the binary WOM vector to separate a binary representation from a data set.

A data device comprising:

• a memory configured to store data values:
• a memory controller that is configured to store the data values in the memory by performing operations comprising:
• receiving a new data set for a rank of a plurality of ranks to be stored in the memory device wherein the memory device comprises a plurality of cells;
• reading a current state of candidate cells within the plurality of cells wherein candidate cells are used to store the new data set;
• creating a binary representation of the plurality of cells used to store the new data set;
• using a WOM code to combine the binary representation with the new data set to create a binary WOM vector;
• modifying the binary WOM vector to equal quantities of 1's and 0's within the candidate cells creating a new data vector;
• writing the new data vector to the candidate cells.

A data device comprising:

• a memory configured to store data values:
• a memory controller that is configured to store the data values in the memory by performing operations comprising:
• receiving a new data set m for a rank to store in the memory device wherein the memory device comprises a plurality of cells;
• reading a current state of the plurality of cells within the plurality of cells are arranged according to a rank modulation scheme and the plurality of cells are used to store the new data set;
• determine a new multi-permutation to be written to the plurality of cells representing the received data set m determined in accordance with a predetermined cost;
• write the new multipermutation to memory.

A data device comprising:

• a memory configured to store data values:
• a memory controller that is configured to store the data values in the memory by performing operations comprising:
• receiving a data value comprising a plurality of data sets wherein each data set is a set of values representing a rank in a plurality of ranks and repeating for the data sets in the data value, operations comprising:
• receiving a new data set for a rank of the plurality of ranks to be stored in the memory device wherein the memory device comprises a plurality of cells;
• reading a current state of candidate cells within the plurality of cells wherein candidate cells are used to store the new data set;
• creating a binary representation of the plurality of cells used to store the new data set;
• using a WOM code to combine the binary representation with the new data set to create a binary WOM vector;
• modifying the binary WOM vector to equal quantities of 1's and 0's within the candidate cells creating a new data vector;
• writing the new data vector to the candidate cells.

A data device comprising:

• reading a plurality of cells and determining a multi-permutation stored in the plurality of cells;
• identifying a group of cells in the plurality of cells, contained within each rank of a plurality of ranks;
• for each rank, performing the steps of:
• reading a new data vector from the rank;
• modifying the new data vector to recreate a binary WOM vector;
• using a WOM code on the binary WOM vector to separate a binary representation from a data set.