A data storage device is disclosed comprising a storage medium. First data is encoded into a first codeword comprising a plurality of i-bit symbols, and second data is encoded into a second codeword comprising a plurality of j-bit symbols, wherein i is different than j and a first code rate of the first codeword is less than a second code rate of the second codeword. The first codeword and the second codeword are symbol interleaved to generate an interleaved codeword, and the interleaved codeword is written to the storage medium.

According to one embodiment, a storage device includes a detector, a demodulator, a controller, and a recorder. When a user data item is split data including first data being at least part of a first code word and second data being at least part of a second code word, the controller sets a start position of the second data for forced search of the second code word on the basis of the position of a sync mark recorded in the recorder when the forced search of the first code word has succeeded.

A data storage device is disclosed comprising a storage medium. First data is encoded into a first codeword comprising a plurality of i-bit symbols, and second data is encoded into a second codeword comprising a plurality of j-bit symbols, wherein i is different than j and a first code rate of the first codeword is less than a second code rate of the second codeword. The first codeword and the second codeword are symbol interleaved to generate an interleaved codeword, and the interleaved codeword is written to the storage medium.

A data storage device is disclosed comprising a storage medium. Input data is encoded according to at least one channel code constraint to generate first data and second data. The first data is encoded into a first codeword, and the second data is encoded into a second codeword, wherein a first code rate of the first codeword is less than a second code rate of the second codeword. The first codeword and the second codeword are interleaved to generate an interleaved codeword, and the interleaved codeword is written to the storage medium.

According to various embodiments, a joint detector/decoder device may be provided. The joint detector/decoder device may include: an input circuit configured to receive an input signal; a splitting determination circuit configured to determine whether a survivor is to be split based on a parity check criterion; and a survivor splitting circuit configured to produce a plurality of survivors of a next instance based on at least one survivor of a previous instance and based on the input signal, if it is determined that the survivor of the previous instance is to be split; wherein each survivor has an associated bit sequence.

According to one embodiment, a magnetic disk device includes a disk, a head configured to write data to and read data from the disk, and a controller configured to compress data transmitted with a specific size into compressed data, add data of a first pattern to the compressed data to generate first data having the specific size, execute an encoding process to the generated first data, output second data obtained by encoding the first data, and execute a decoding process to the second data input from outside based on the first pattern.