Disk array device, parity data generating circuit for RAID and Galois field multiplying circuit

A Galois field multiplying circuit, comprising:

• a Galois field multiplying table;
• a longitudinal index table making circuit for generating the index table information of the longitudinal direction by indexing the Galois field multiplying table from the longitudinal direction by using a multiplication coefficient;
• a transversal index table making circuit for generating the index table information of the transversal direction by indexing the Galois field multiplying table from the transversal direction by using the multiplication coefficient;
• an upper order data converting circuit and a lower order data converting circuit for dividing data from the generated index table information into an upper order data portion and a lower order data portion and converting these data into data for redundant array of independent disks;
• and
• an upper order parity inverting circuit and a lower order parity inverting circuit for dividing parity with respect to the data from the generated index table information into an upper order parity portion and a lower order parity portion and converting this parity into parity with respect to the data for redundant array of independent disks.

A Galois field multiplying circuit, comprising:

• a Galois field multiplying table;
• a longitudinal index table making circuit for generating the index table information of the longitudinal direction by indexing the Galois field multiplying table from the longitudinal direction by using a multiplication coefficient;
• a transversal index table making circuit for generating the index table information of the transversal direct by indexing the Galois field multiplying table from the transversal direction by using the multiplication coefficient;
• an even data converting circuit and an odd data converting circuit for dividing data from the generated index table information into an even data position and an odd data position and converting these data into data for redundant array of independent disks;
• and an even parity inverting circuit and an odd parity inverting circuit for dividing parity with respect to the data from the generated index table information into an even parity position and an odd parity position and converting this parity into parity with respect to the data for redundant array of independent disks.

A Galois field multiplying circuit, comprising:

• a Galois field multiplying table;
• a longitudinal index table making circuit for generating the index table information of the longitudinal direction by indexing the Galois field multiplying table from the longitudinal direction by using a multiplication coefficient;
• a transversal index table making circuit for generating the index table information of the transversal direction by indexing the Galois field multiplying table from the transversal direction by using the multiplication coefficient;
• an upper order data converting circuit and a lower order data converting circuit for dividing data from the generated index table information into an upper order data portion and a lower order data portion and converting these data into data for redundant array of independent disks;
• and
• an error correcting code converting circuit for converting error correcting code with respect to the data into error correcting code with respect to the data for redundant array of independent disks.

A Galois field multiplying circuit comprising:

• a Galois field multiplying table having a conversion table for data and a conversion table for parity;
• a longitudinal index table making circuit for generating a longitudinal inverting table for parity and a longitudinal converting table for data by indexing said Galois field multiplying table from the longitudinal direction by using a multiplication coefficient;
• a transversal index table making circuit for generating a transversal converting table for data and a transversal inverting table for parity by indexing said Galois field multiplying table from the transversal direction by using the multiplication coefficient;
• an upper order data converting circuit for selecting the longitudinal converting table for data generated by said longitudinal index table making circuit by each decomposing data of an upper order data portion of data, and obtaining a multiplying result of the Galois field;
• a lower order data converting circuit for selecting the transversal converting table for data generated by said transversal index table making circuit by each decomposing data of a lower order data portion of data, and obtaining a multiplying result of the Galois field;
• an upper order parity inverting circuit for obtaining an inverting result of an upper order parity portion in which an XOR logic operation is performed with respect to each decomposing parity of the upper order parity portion of the parity and the multiplying result of the Galois field obtained by selecting the transversal inverting table for parity generated by said transversal index table making circuit by each decomposing data of the upper order data portion of the data;
• and
• a lower order parity inverting circuit for obtaining an inverting result of the lower order parity in which the XOR logic operation is performed with respect to each decomposing parity of the lower order parity portion of the parity and the multiplying result of the Galois field obtained by selecting the longitudinal inverting table for parity generated by said longitudinal index table making circuit by each decomposing data of the upper order data portion of the data.

A Galois field multiplying circuit comprising:

• a Galois field multiplying table having a conversion table for data and a conversion table for parity;
• a longitudinal index table making circuit for generating a longitudinal inverting table for parity and a longitudinal converting table for data by indexing said Galois field multiplying table from the longitudinal direction by using a multiplication coefficient;
• a transversal index table making circuit for generating a transversal converting table for data and a transversal inverting table for parity by indexing said Galois field multiplying table from the transversal direction by using the multiplication coefficient;
• an even data converting circuit for selecting the longitudinal converting table for data generated by said longitudinal index table making circuit by each decomposing data of an even data position of data, and obtaining a multiplying result of the Galois field;
• an odd data converting circuit for selecting the transversal converting table for data generated by said transversal index table making circuit by each decomposing data of an odd data position of data, and obtaining a multiplying result of the Galois field;
• an even parity inverting circuit for obtaining an inverting result of the even parity in which an XOR logic operation is performed with respect to each decomposing parity of the upper order parity portion of the parity and the multiplying result of the Galois field obtained by selecting the transversal inverting table for parity generated by said transversal index table making circuit by each decomposing data of the even data position of the data;
• and
• an odd parity inverting circuit for obtaining an inverting result of the odd parity in which the XOR logic operation is performed with respect to each decomposing parity of the lower order parity portion of the parity and the multiplying result of the Galois field obtained by selecting the longitudinal inverting table for parity generated by said longitudinal index table making circuit by each decomposing data of the odd data position of the data.

A Galois field multiplying circuit, comprising:

• a Galois field multiplying table having a conversion table for data and a conversion table for parity;
• an error correcting code converting table corresponding to each decomposing data of the data;
• a longitudinal index table making circuit for generating a longitudinal inverting table for parity and a longitudinal converting table for data by indexing said Galois field multiplying table from the longitudinal direction by using a multiplication coefficient;
• a transversal index table making circuit for generating a transversal converting table for data and a transversal inverting table for parity by indexing said Galois field multiplying table from the transversal direction by using the multiplication coefficient;
• an error correcting code index table making circuit for generating a conversion table for error correcting code by indexing said error correcting code converting table by using the multiplication coefficient;
• an upper order data converting circuit for selecting the longitudinal converting table for data generated by said longitudinal index table making circuit by each decomposing data of an upper order data portion of data, and obtaining a multiplying result of the Galois field;
• a lower order data converting circuit for selecting the transversal converting table for data generated by said transversal index table making circuit by each decomposing data of a lower order data portion of data, and obtaining a multiplying result of the Galois field;
• and
• an error correcting code converting circuit for selecting the error correcting code converting table generated by said error correcting code index table making circuit by each decomposing data of the data, and converting the error correcting code with respect to the data into error correcting code with respect to data for redundant array of independent disks.