Data storage device employing multi-tier coding for magnetic tape
AssigneeWestern Digital Technologies, Inc.
InventorsRichard L. Galbraith, Weldon M. Hanson, Derrick E. Burton, Niranjay Ravindran, Iouri Oboukhov
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Abstract
A data storage device is disclosed comprising at least one head configured to access a magnetic tape. Data is read from the magnetic tape to generate a read signal which is processed to decode a first M blocks of low density parity check (LDPC) type codewords using a LDPC type decoder. First un-converged codewords out of the first M blocks are decoded using a first M-blocks parity, and second un-converged codewords out of the first M blocks are decoded using an erasure code.
Claims18
A data storage device configured to access a magnetic tape, the data storage device comprising:
- at least one head configured to access the magnetic tape;
- and
- control circuitry configured to:
- read data from the magnetic tape to generate a read signal;
- process the read signal to decode a first M blocks of low density parity check (LDPC) type codewords using a LDPC type decoder;
- decode first un-converged codewords out of the first M blocks using a first M-blocks parity;
- and
- decode second un-converged codewords out of the first M blocks using an erasure code.
A data storage device configured to access a magnetic tape comprising a plurality of data tracks, the data storage device comprising:
- a plurality of heads configured to access the plurality of data tracks;
- and
- control circuitry configured to:
- read data from each of the plurality of data tracks to generate a plurality of read signals;
- process the plurality of read signals using a plurality of Viterbi type detectors to generate an array of detected symbols representing a block of low density parity check (LDPC) type codewords out of a first M blocks of LDPC type codewords, wherein each LDPC type codeword comprises a plurality of symbols spanning a diagonal of the array;
- process the detected symbols to decode the first M blocks of LDPC type codewords using a LDPC type decoder;
- decode first un-converged codewords out of the first M blocks using a first M-blocks parity;
- and
- decode second un-converged codewords out of the first M blocks using an erasure code.
A data storage device configured to access a magnetic tape, the data storage device comprising:
- at least one head configured to access the magnetic tape;
- a means for reading data from the magnetic tape to generate a read signal;
- a means for processing the read signal to decode a first M blocks of low density parity check (LDPC) type codewords using a LDPC type decoder;
- a means for decoding first un-converged codewords out of the first M blocks using a first M-blocks parity;
- and
- a means for decoding second un-converged codewords out of the first M blocks using an erasure code.
A method of operating a data storage device, the method comprising:
- reading data from a magnetic tape to generate a read signal;
- processing the read signal to decode a first M blocks of low density parity check (LDPC) type codewords using a LDPC type decoder;
- decoding first un-converged codewords out of the first M blocks using a first M-blocks parity;
- and
- decoding second un-converged codewords out of the first M blocks using an erasure code.
A method of operating a data storage device, the method comprising:
- reading data from each of a plurality of data tracks on a magnetic tape to generate a plurality of read signals;
- processing the plurality of read signals using a plurality of Viterbi type detectors to generate an array of detected symbols representing a block of low density parity check (LDPC) type codewords out of a first M blocks of LDPC type codewords, wherein each LDPC type codeword comprises a plurality of symbols spanning a diagonal of the array;
- processing the detected symbols to decode the first M blocks of LDPC type codewords using a LDPC type decoder;
- decoding first un-converged codewords out of the first M blocks using a first M-blocks parity;
- and
- decoding second un-converged codewords out of the first M blocks using an erasure code.
Dependencies are inferred from the claim text.