1. A method for transferring data in a data processing unit comprising the data processing unit performing steps of: receiving a first address; if the first address contains a predetermined address component, then producing a second address and reading data from or writing data to a memory location at the second address; and if the first address does not contain the predetermined address component, then reading data from or writing data to a memory location at the first address, the first address comprising a plurality of address bits, wherein the predetermined address component comprises less than all of the address bits of the first address, the first address and the second address having a common address component.