A memory structure includes a memory module divided into low order banks and high order banks. The low order banks are used as conventional memory. The high order banks are used as either conventional memory or ECC memory, depending upon routing of data. In one embodiment, data from the high order banks are routed through a primary multiplexer to a data bus when the high order banks are used as conventional memory. When the high order banks are used as ECC memory, data from the auxiliary section is routed through the primary multiplexer to an error correction circuit. A secondary multiplexer combines ECC bits from the auxiliary section of the module or a dedicated ECC memory on a motherboard. The auxiliary section thus supplements the onboard ECC memory to provide support for an effectively larger ECC memory for use with error intolerant applications that require error correction.