Patent attributes
A nonvolatile memory storage controller is provided for delivering log likelihood ratios (LLRs) to a low-density parity check (LDPC) decoder for use in the decoding of an LDPC encoded codeword. The controller includes read circuitry for reading an LDPC encoded codeword stored in a nonvolatile memory storage module using a plurality of soft-decision reference voltages to provide a plurality of soft-decision bits representative of the codeword. The controller further includes a plurality of lifetime specific LLR look-up tables representative of the lifetime threshold voltage distribution of the memory storage module, wherein each of the plurality of lifetime specific LLR look-up tables comprises a plurality of LLRs representative of a specific point in the lifetime of the memory storage module for each of the plurality of soft-decision bits. The controller provides the LLRs from the appropriate LLR look-up table to an LDPC decoder for the subsequent decoding of the codeword.
