12. A computer system for storing data, comprising: an input device that receives data from a user; a processor coupled to the input device, the processor being structured to process data according to programmed instructions; a memory module that stores a plurality of data words for use by the processor, each data word including a plurality of consecutive data bits divided into N subsets of data bits having data values, where N is an integer greater than 1, the data bits in each subset comprising every N.sup.th data bit in the data word; and a memory controller coupling the memory module to the processor, the memory controller being structured to create a separate error correction code for each of the subsets of each of the plurality of data words stored in the memory module, each error correction code including a plurality of check bits computed based on the data bits of the subset corresponding to the error correction code.
13. The computer system of claim 12 wherein the memory controller includes N error correction modules each structured to create the error correction code for a corresponding one of the subsets of each data word.