Adaptive DSP generation of read thresholds for gaussian and non-gaussian distributions in solid state storage using cumulative observed counts

A system, comprising:

• a memory that is configured to store information associated with read threshold generation, including a second and earlier level count disparity;
• and
• a read controller that is coupled to the memory and that is configured to:
• determine a level count disparity based at least in part on:
• (1) an expected count of a plurality of cells in solid state storage and (2) an observed count of the plurality of cells in the solid state storage, wherein the observed count is associated with a number of cells in the solid state storage that are activated by performing a single read on the solid state storage using a previous read threshold;
• determine a next read threshold based at least in part on the level count disparity, including by:
• determining a direction of the next read threshold relative to the previous read threshold based at least in part on the level count disparity and independent of the second and earlier level count disparity;
• and
• determining a magnitude of the next read threshold based at least in part on the level count disparity and the second and earlier level count disparity;
• perform a read on the solid state storage using the next read threshold to obtain read data, wherein error correction decoding is performed on the read data;
• perform a plurality of reads on the solid state storage at integer increments of Δ to obtain a plurality of read data at increments of Δ, wherein Δ is a smallest voltage increment supported by the solid state storage;
• determine a second next read threshold based at least in part on an inversely weighted average and the plurality of read data at increments of Δ;
• and
• perform a read on the solid state storage using the second next read threshold to obtain second read data.