Combined group ecc protection and subgroup parity protection

A computer system for generating a matrix P to provide an error correction code (ECC) word for a given group of n bits and to provide parity bits for subgroups of said given group of n bits, the matrix P including a multitude of rows and columns, the computer system comprising:

• a memory unit for storing data;
• One or more processing units coupled to the memory and configured for:
• generating permutations of m bit wide vectors, each of the vectors having an odd number of three or more elements with a value of one and the other elements with a value zero;
• assigning the permutations to rows of the matrix P while adhering to a defined group of conditions;
• and
• if not all the rows of P are assigned, increasing m, and repeating the generating and assigning steps;
• and
• wherein multiplying said given group of n bits with P produces m error correction code protection bits, and two of the columns of P provide parity bits for parity protection for subgroups of said given group of n bits.

A computer readable storage device, tangibly embodying a program of instructions executable by a computer to perform method steps for generating a matrix P to provide an error correction code (ECC) for a given group of n bits and to provide parity bits for subgroups of said given group of n bits, the matrix P including a multitude of rows and columns, said method steps comprising:

• generating permutations of m bit wide vectors, each of the vectors having an odd number of three or more elements with a value of one and the other elements with a value zero;
• assigning the permutations to rows of the matrix P while adhering to a defined group of conditions;
• and
• if not all the rows of P are assigned, increasing m, and repeating the generating and assigning steps;
• and
• wherein multiplying said given group of n bits with P produces m error correction code protection bits, and two of the columns of P provide parity bits for parity protection for subgroups of said given group of n bits.