Advanced bitwise operations and apparatus in a multi-level system with nonvolatile memory

摘要

A digital system, components and method are configured with nonvolatile memory for storing digital data using codewords. The data is stored in the memory using multiple bits per memory cell of the memory. A code efficiency, for purposes of write operations and read operations relating to the memory, can be changed on a codeword-to-codeword basis based on input parameters. The code efficiency can change based on changing any one of the input parameters including bit density that is stored by the memory. Storing and reading fractional bit densities can be performed.

主权项

1. As part of a digital system using nonvolatile memory including a plurality of memory cells for storing digital data such that at least some of the memory cells can store more than one bit, an apparatus comprising:
an encoder that receives an input data stream that is provided by the system for producing an output data stream that is based on a selected number of bits per cell coding for storage in the memory cells and said encoder is selectively operable in a first mode based on one or more input parameters to produce a first bit density for storage in the memory cells as the selected number of bits per cell and operable at least in a second mode to produce a second bit density that is different than the first bit density responsive to a change in said input parameters for selectably changing the number of bits per cell coding during operation thereof.