Rank-modulation rewriting codes for flash memories

A data device, comprising:

• a memory device configured to store data values, wherein the memory device comprises a plurality of memory cells;
• and
• a memory controller coupled to the memory device, wherein the memory controller is configured to store the data values in the memory device by performance of operations that include:
• receive a set of new data values to be stored in memory cells of the plurality of memory cells, that contain a set of current data values, wherein the received set of new data values includes a set of symbols according to a rank modulation coding scheme;
• retain analog levels of the plurality of memory cells that contain the received set of new data values;
• and
• add, based on the analog levels of the plurality of memory cells, a charge to each memory cell of the plurality of memory cells,
• wherein to add the charge to each memory cell of the plurality of memory cells, the memory controller is configured to program a group of rank locations in the memory device such that a pro rammed value of a rank location is increased until the programmed value is greater than a programmed value of a subsequent rank location by a minimum cell differentiation amount, and
• wherein the programmed group of rank locations facilitate reduction in risk of overshoot of the charge, to enable reuse of the memory device for successive writes.

A memory controller to store data values in a memory that includes a plurality of memory cells, the memory controller comprising:

• a host interface configured to receive a new data set for a rank of a plurality of ranks to be stored in the memory;
• a memory interface configured to read a current state of the plurality of memory cells to store the received new data set;
• and
• a microcontroller configured to:
• add a charge to each memory cell of the plurality of memory cells, wherein the addition of the charge to each memory cell of the plurality of memory cells comprises a program of a group of rank locations in the memory, wherein to program the group of rank locations, the microcontroller is configured to:
• use an update scheme that enables rewrite of the memory multiple times to create another new data set;
• and
• write the another new data set to the plurality of memory cells,
• wherein the program of the group of rank locations by use of the update scheme facilitates reduction in risk of overshoot of the charge, to enable reuse of the memory for successive writes.