Abstract: According to the DDA technique, incremental signals are processed which usually consist of two separate signals for value and sign. An arithmetic element then comprises at least one register and one adder/subtractor. A complex circuit, for example, a control system comprising a plurality of controllers, requires a number of arithmetic elements, partly having different functions, which are to be linked. A number of arithmetic elements are realized in that use is made of a microprocessor which comprises some additional external circuits and which successively deals with the separate arithmetic elements. For effective use of the microprocessor, there is provided a command control device which modifies the microprogram commands, notably in dependence of the increment to be processed; however, this can also be done by other control signals. This step enables more efficient and faster jumps in the microprogram which are not subject to conditions.