US Patent 9484098 Smart reread in nonvolatile memory

A population of memory cells are programmed and an indicator of a first number of the memory cells programmed to a first state is recorded. Subsequently, a first read operation is performed using a first set of read parameters to identify a second number of the memory cells that are read as being in the first state. The difference between the first number and the second number is determined and a second set of read parameters for a second read (reread) is selected accordingly.