1. A method for expanding a data memory for a microprocessor architecture comprising a bank select accessing scheme for accessing data memory which is divided into a plurality of memory banks and a bank select register configured to select a memory bank and wherein the microprocessor architecture comprises an instruction set having a dedicated instruction for selecting a memory bank; wherein an opcode of the dedicated bank select instruction provides for a maximum of n bits payload thereby providing for an address value which is configured to select a maximum of 2 n memory banks, the method comprising the steps of: using an opcode of a test instruction that provides for m bits of payload for a new bank select instruction, wherein m>n; and using an opcode of the dedicated bank select instruction for a new test instruction.