Patent ID: 6877126

Claim:
A method of reproducing data recorded as blocks of a predetermined size each block having an error protection code applied thereto and comprising a series of several sub-blocks, the method comprising: (a) reading in parallel a set of N sub-sequences of data starting at N respective locations chosen without restriction to boundaries of said blocks or sub-blocks, the set of N sub-sequences of data encompassing a contiguous portion of a first sequence of data; (b) during said reading step, identifying within each sub-sequence a series of sub-blocks forming a part of a block and, in the absence of data from the start of the block, processing the series of sub-blocks in accordance with predetermined rules to accumulate a partial syndrome relating to a complete syndrome for the block, obtained by applying the error protection code to the block including all sub-blocks thereof; (c) upon reaching the end of the block, accumulating a syndrome for a next block within the sub-sequence; (d) during said reading step subsequently identifying in another of said sub-sequences a series of sub-blocks forming a starting part of the block whose end part has been processed and processing said sub-blocks to accumulate a remainder syndrome relating to the complete syndrome for the block; and (e) combining the remainder syndrome with the partial syndrome so as to obtain the complete syndrome for the block.