In a data processing system having a plurality of error coding function circuitries, a method includes receiving an address which indicates a first storage location for storing a first data value; using a first portion of the address to select one of the plurality of error coding function circuitries as a selected error coding function circuitry; and using the selected error coding function circuitry to generate a first checkbit value, wherein the selected error coding function circuitry uses the first data value to generate the first checkbit value. When the first portion of the address has a first value, a first one of the plurality of error coding function circuitries is selected as the selected error coding function circuitry. When the first portion of the address has a second value, a second one of the plurality of error coding function circuitries is selected as the selected error coding function circuitry.