1. A method of providing combined error code protection and subgroup parity protection for a given group of n bits, the method comprising the steps of: identifying a number, m, of redundant bits for said error protection; and constructing a matrix P, wherein multiplying said given group of n bits with P produces m redundant error correction code (ECC) protection bits, and two columns of P provide parity protection for subgroups of said given group of n bits.