| 摘要 |
PURPOSE: A device of modulating error correction data is provided to sequentially arrange error correction data as 8-bit data columns, and to convert the data as codeword data to output the codeword data, then to sequentially rearrange the codeword data as 12-bit data columns, thereby modulating the error correction data by using an RLL(Run Length Limited) modulation system in real time. CONSTITUTION: An input data sequencer(51) sequentially arranges error correction data as 8-bit input data according to an RLL modulation system. A pattern comparator(52) compares the sequentially-inputted error correction data with many reference patterns, and converts the data into one or two codewords stored in a conformed pattern, then outputs the converted data. An output data sequencer(53) sequentially arranges the one or two codewords into 12-bit output data. A DSV(Digital Sum Value) calculator(54) converts the one or two 12-bit codeword data into NRZI(Non-Return to Zero Inverted) data, and calculates DSV values of 0 and 1 included in accumulative NRZI data, then selectively outputs NRZI data having a small DSV value.
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