Error recovery using adaptive LLR lookup table

A storage system controller, comprising:

• a processor configured to:
• select a set of decoding factors for a multi-read operation to read a non-volatile storage device multiple times, the set of decoding factors including an aggregation mode for aggregating read results of multiple reads;
• issue a command to the non-volatile storage device to read user data according to the set of decoding factors;
• a mapping engine configured to generate a plurality of Log-Likelihood Ratio (LLR) values from a pre-selected set of LLR value magnitudes based on the set of decoding factors;
• and
• a soft decision decoder configured to:
• obtain an LLR value from the plurality of LLR values using an aggregated read result as an index, the aggregated read result being obtained in accordance with the aggregation mode;
• and
• perform a soft decision decoding using the LLR value.

A method, comprising:

• pre-selecting a set of Log-Likelihood Ratio (LLR) values;
• initiating a plurality of multi-read operations by selecting a respective set of decoding factors for each of the plurality of multi-read operations and issuing read commands corresponding to the plurality of multi-read operations, each respective set of decoding factors including an aggregation mode for aggregating read results of multiple reads;
• and
• processing the plurality of multi-read operations using a mapping engine and a soft decision decoder in a hardware pipeline,
• wherein, in a first pipeline stage of the hardware pipeline, the mapping engine generates an LLR lookup table (LUT) from the set of LLR value magnitudes based on a set of decoding factors corresponding to one of the plurality of multi-read operations that has finished reading data, and
• in a second pipeline stage of the hardware pipeline, the soft decision decoder performs soft decision decoding using an LLR value obtained from the LLR LUT with an aggregated read result as an index, the aggregated read result being obtained in accordance with the aggregation mode in the set of decoding factors corresponding to the one of the plurality of multi-read operations that has finished reading data.

A method, comprising:

• selecting a set of decoding factors for a multi-read operation to read a non-volatile storage device multiple times, the set of decoding factors including an aggregation mode for aggregating read results of multiple reads;
• issuing a command to the non-volatile storage device to read user data according to the set of decoding factors;
• generating a plurality of Log-Likelihood Ratio (LLR) values using a mapping engine that outputs the plurality of LLR values from a pre-selected set of LLR value magnitudes based on the set of decoding factors;
• obtaining an aggregated read result in accordance with the aggregation mode;
• obtaining an LLR value from the plurality of LLR values using the aggregated read result as an index;
• and
• performing a soft decision decoding using a soft decision decoder with LLR value obtained from the plurality of LLR values, wherein the mapping engine and the soft decision decoder are two pipeline stages of a hardware pipeline for processing data for a plurality of multi-read operations.