Mapping between program states and data patterns

A method, comprising:

• storing a N unit data pattern in a plurality (G) of memory cells such that the G memory cells store N/G units of data per memory cell, wherein a combination of respective program states of the G memory cells maps to at least one constellation point corresponding to the N unit data pattern;
• wherein the at least one constellation point is part of a mapping constellation comprising at least a first shell of constellation mapping points and a second shell of constellation mapping points;
• and
• wherein quantities of constellation points corresponding to the respective first and second shells are determined, at least partially, based on a polynomial expression of order equal to G.

An apparatus, comprising:

• an array of memory cells each programmable to a plurality (L) of program states;
• and
• a controller configured to:
• store a particular N unit data pattern in a plurality (G) of memory cells each programmed to a respective one of the L program states;
• map, via a mapping constellation, the particular N unit data pattern to at least one of 2N program state combinations, wherein the mapping constellation maps between the 2N program state combinations and a respective 2N N unit data patterns;
• wherein the mapping is based, at least partially, on a polynomial expression of order equal to G, a first term of the polynomial expression corresponding to a first mapping shell and a second term of the polynomial expression corresponding to a second mapping shell.