Multi-mode iterative detector

A storage system comprising:

• a linear block encoder configured to encode data to generate encoded data;
• a write circuit configured to write the encoded data to a storage medium;
• a read circuit configured to read the encoded data from the storage medium;
• a channel decoder configured to, during a first decoding iteration, decode the encoded data to generate first decoded data
• a soft linear block code decoder configured to, during the first decoding iteration, decode the first decoded data to generate second decoded data
• wherein during a second decoding iteration, the channel decoder is configured to decode the encoded data i) subsequent to the soft linear block code decoder decoding the first decoded data and ii) based on the second decoded data;
• and
• a threshold check circuit configured to select:
• an output of the soft linear block code decoder if a number of parity check violations has a first relationship with respect to a threshold, or
• an output of the channel decoder if the number of the parity check violations has a second relationship with respect to the threshold,
• wherein if there are no parity-check violations or a number of decoding iterations performed by the channel decoder and the soft linear block code decoder exceeds a predetermined number, the threshold check circuit is configured to determine if the number of the parity-check violations has the first relationship with respect to the threshold.

A storage system comprising:

• a linear block encoder configured to encode data to generate encoded data;
• a write circuit configured to write the encoded data to a storage medium;
• a read circuit configured to read the encoded data from the storage medium;
• a channel decoder configured to, during a first decoding iteration, decode the encoded data to generate first decoded data;
• a soft linear block code decoder configured to, during the first decoding iteration, decode the first decoded data to generate second decoded data,
• wherein during a second decoding iteration, the channel decoder is configured to decode the encoded data i) subsequent to the soft linear block code decoder decoding the first decoded data and ii) based on the second decoded data;
• and
• a threshold check circuit configured to select:
• an output of the soft linear block code decoder if a number of parity check violations has a first relationship with respect to a threshold, or
• an output of the channel decoder if the number of the parity check violations has a second relationship with respect to the threshold,
• wherein the soft linear block code decoder is configured to determine if there is a parity-check violation based on a parity-check matrix.

A method comprising:

• linear block encoding data to generate encoded data;
• writing the encoded data to a storage medium;
• reading the encoded data from the storage medium;
• during a first decoding iteration, channel decoding the encoded data read from the storage medium to generate first decoded data;
• during the first decoding iteration, soft linear block code decoding the first decoded data to generate second decoded data,
• wherein during a second decoding iteration, the channel decoding of the encoded data is performed based on the second decoded data;
• calculating a number of parity-check violations based on the soft linear block code decoding of the first decoded data;
• and
• selecting
• the first decoded data if the number of the parity-check violations has a first relationship with respect to a threshold, or
• the second decoded data if the number of the parity check violations has a second relationship with respect to the threshold,
• wherein channel decoding the encoded data is based on the second decoded data if number of the parity-check violations is greater than or equal to 1.