1. A microcontroller comprising a data memory divided into a plurality of memory banks wherein special function registers are memory-mapped to more than one memory bank of said plurality of memory banks and wherein said data memory comprises more than one memory bank of said plurality of memory banks that form a block of linear data memory to which no special function registers are mapped, a bank select register which is not mapped to said data memory for selecting a memory bank, and an indirect access register mapped to more than one memory bank, wherein the bank select register is the only register for memory bank selection, the microcontroller being furthermore configured to comprise an instruction set comprising: a plurality of instructions operable to directly address all memory locations within a selected bank; at least one instruction that provides access to said bank select register; at least one instruction performing an indirect address to said data memory using said indirect access register.