A microprocessor includes internal registers, an arithmetic and logic
unit, and reads a program memory and executes an instruction set stored
therein. The instruction set includes at least one instruction for
exchanging the contents of both memory locations. The microprocessor
includes an additional internal register connected to an output of the
arithmetic and logic unit, and transfers the contents of a first one of
the memory locations to be exchanged into the additional register when
executing the instruction set. The microprocessor further transfers the
contents of a second one of the memory locations to be exchanged into the
first memory location, and transfers the contents of the additional
register into the second memory location.