Method and system for optical disk decoding

A method for optical disk inner code decoding, for decoding an error correction code (ECC) block, the ECC block including a plurality of data sectors, each data sector including a plurality of rows of data, the method comprising the steps of:

• (a1) determining whether the K-th data sector corresponding to the I-th row is set to be correct:
• if so, proceeding to step (g1);
• or
• if not, proceeding to steps (b1) and (h1) simultaneously;
• (b1) determining whether a syndrome corresponding to the I-th row is equal to zero:
• if so, proceeding to step (e1);
• or
• if not, proceeding to steps (c1)
• (c1) decoding the data of the I-th row;
• (d1) determining whether the decoding of the data of the I-th row is complete:
• if so, proceeding to step (e1);
• or
• if not, proceeding to step (f1);
• (e1) correcting the data of the I-th row, setting the data of the I-th row to be correct and proceeding to step (g1);
• (f1) setting an erasure flag corresponding to the I-th row to be a first value;
• (g1) determining whether the inner code decoding of the entire ECC block is complete:
• if so, terminating the method;
• or
• if not, repeating from the step (a1) for the (K+1)th data sector;
• (h1) performing descrambling;
• (i1) determining whether the following is true:
• the K-th data sector is passed in the EDC check and is set to be correct and no error correction is performed on the K-th data sector:
• if so, proceeding to step (j1);
• or
• if not, proceeding to step (k1);
• (j1) setting the K-th data sector to be correct;
• and
• (k1) setting the K-th data sector to be undetermined.

A method for optical disk outer code decoding, for decoding an error correction code (ECC) block, the ECC block including a plurality of data sectors, the ECC block including a plurality of columns of data, each of the columns of data corresponding to one of the data sectors, the method comprising the steps of:

• (a2) determining whether a syndrome corresponding to the J-th column is equal to zero:
• if so, proceeding to step (g2);
• or
• if not, proceeding to step (b2);
• (b2) decoding the data of the J-th column;
• (c2) determining whether the decoding of the data of the J-th column is complete:
• if so, proceeding to step (d2);
• or
• if not, proceeding to steps (f2);
• (d2) determining whether the data sector where a correction obtained from the decoding of the step (b2) belongs is passed in the EDC check:
• if so, proceeding to step (e2);
• or
• if not, proceeding to steps (g2);
• (e2) reserving the data sector;
• (f2) setting an erasure flag corresponding to the J-th column to be a first value and proceeding to step (i2);
• (g2) correcting the data of the J-th column;
• (h2) setting the J-th column to be correct;
• and
• (i2) determining whether the outer code decoding of the entire ECC block is complete:
• if so, terminating the method;
• or
• if not, repeating from the step (a2) after increasing the value of J by one.

A system for optical disk decoding, for receiving message data from an optical disk, and for decoding an error correction code (ECC) block of the message data, the system comprising:

• an eight-to-fourteen modulation (EFM) demodulator for receiving the message data from the optical disk and performing EFM demodulation of the message data, obtaining the ECC block;
• an inner code decoder for performing inner code decoding of the ECC block;
• an outer code decoder for performing outer code decoding of the ECC block;
• a descrambling and EDC checking unit for performing descrambling and EDC checking;
• and
• a descrambler for performing descrambling;
• wherein the ECC block is inputted into the inner code decoder and the descrambling and EDC checking unit simultaneously, and EDC checking of the ECC block is performed during the outer code decoding of the ECC block.