Error detecting code addition circuit, error detection circuit and method, and disc apparatus

An error detector for detecting an error by calculating an error detecting value of a code string added with an error detecting code where a detection target code string to be error-detected comprises k, k being a natural number, number of bits, each bit data being associated with a first bit sequence, and the error detecting value is obtained when the detection target code string is processed in the first bit sequence by a predetermined operation method, the error detector comprising:

• a substitute value output section outputting at least part of each substitute value associated with the first bit sequence of each bit data of the detection target code string;
• and
• an error detecting value calculation section calculating the error detecting value of the detection target code string according to an output result of the substitute value output section,
• wherein the error detecting value calculation section calculates the error detecting value by processing each bit data of the detection target code string and the substitute value corresponding to the first bit sequence in a different sequence, the different sequence is different from the first bit sequence.

An error detecting method, comprising:

• inputting a detection target code string in a second sequence different from a first sequence to calculate an error detecting value that is obtained when a detection target code string to be error-detected that contains K, K being a natural number, number of bytes, each byte data being associated with a first sequence, is processed in the first sequence by a predetermined operation method;
• generating a specific substitute value corresponding to the first sequence of each byte data by referring to a table storing at least part of K number of specific substitute values associated with the first sequence;
• and
• calculating the error detecting value by processing each byte data of the detection target code string and the specific substitute value corresponding to the first sequence in the second sequence.

An error detecting code addition circuit for generating an error detecting code addition code string of K, K being a natural number, number of bytes composed of user data added with an error detecting code from a processing target code string of K number of bytes containing user data, where the processing target code string has each data associated with a first sequence, and the error detecting code addition code string is obtained by processing the processing target code string in the first sequence by a predetermined operation process, the error detecting code addition circuit comprising:

• a substitute value output section outputting a specific substitute value corresponding to the first sequence of each byte data of the processing target code string;
• and
• a code string generation section calculating the error detecting code addition code string according to an output result of the substitute value output section,
• wherein the code string generation section generates the error detecting code addition code string by processing each byte data of the processing target code string and the specific substitute value corresponding to the first sequence in a second sequence different from the first sequence.

A disc apparatus, comprising:

• a reading section reading error detecting code addition code string added with an error detecting code;
• and
• an error detection section detecting an error by calculating an error detecting code of the error detecting code addition code string,
• wherein the error detecting code addition code string contains K, K being a natural number, number of bytes, each byte data associated with the first sequence,
• wherein the error detecting value is obtained when a detection target code string is processed in the first sequence with a predetermined operation method,
• wherein the error detection section includes:
• a substitute value output section outputting a specific substitute value corresponding to the first sequence of each byte data in the error detecting code addition code string;
• and
• an error detecting value calculation section calculating the error detecting value in the error detecting code addition code string according to an output result of the substitute value output section, and
• wherein the error detecting value calculation section calculates the error detecting value by processing each byte data of the error detecting code addition code string and the specific substitute value corresponding to the first sequence in a second sequence different from the first sequence.

An disc apparatus, comprising:

• an error detecting code addition section generating an error detecting code addition code string of K, K being a natural number, number of bytes composed of user data added with an error detecting code from a processing target code string of K number of bytes containing user data;
• and
• a recording section recording data generated based on the error detecting code addition code string,
• wherein the processing target code string has each byte data associated with a first sequence,
• wherein the error detecting code addition code string is obtained by processing the processing target code string in the first sequence with a predetermined operation method,
• wherein the error detecting code addition section includes:
• a substitute value output section outputting a specific substitute value corresponding to the first sequence of each byte data of the processing target code string;
• and
• a code string generation section calculating the error detecting code addition code string according to an output result of the substitute value output section, and
• wherein the code string generation section generates the error detecting code addition code string by processing each byte data of the processing target code string and the specific substitute value corresponding to the first sequence in a second sequence different from the first sequence.

A disc apparatus, comprising:

• a descrambler generating descrambled code string by descrambling scrambled code string obtained based on each byte data of a code string of K, K being a natural number, number of bytes, each byte associated with a first sequence, and a scramble value corresponding to the first sequence of the byte data;
• and
• an error detector detecting an error by calculating an error detecting value of the descrambled code string,
• wherein each scramble value corresponding to the first sequence is obtained by performing a predetermined operation corresponding to the first sequence on an initial value,
• wherein each byte data of the descrambled code string is associated with the first sequence,
• wherein the error detecting value is obtained when the descrambled code string is processed in the first sequence with a predetermined operation method,
• wherein the descrambler includes:
• a scramble value generation section generating a scramble value corresponding to the first sequence of each byte data in the descrambled code string that is input in a second sequence different from the first sequence;
• and
• a code string operation section calculating the descrambled data from the input byte data and the scramble value corresponding to the first sequence of the byte data, and
• wherein the error detector includes:
• a substitute value output section outputting a specific substitute value corresponding to the first sequence of each byte data of the descrambled code string;
• and
• an error detecting value calculation section calculating the error detecting value by processing each byte data of the descrambled code string and the specific substitute value corresponding to the first sequence in the second sequence according to an output result of the substitute value output section.