differences with respect to preceding switching edges steps 100 to 400 can however also be executed entirely or partly by a program although execution via hardware is preferred times that correspond to the arrival of signals of crankshaft sensor 3 are thus continuously stored and in parallel therewith times that correspond to the arrival of signals of camshaft sensor 5 are continuously stored storage of these values occurs regardless of which of these signals is used to calculate the position pulses or the status of position counter 11 a sufficient number of measured values of crankshaft sensor 3 and of camshaft sensor 5 is therefore always contained in the memory of the circuit assemblage so as to switch over between these two methods at any time this is significant in particular for malfunctions of one of the two sensors for example if crankshaft sensor 3 fails and no measured values of camshaft sensor 5 are stored one complete revolution of the camshaft must first occur before any calculation at all can be performed on the basis of the camshaft sensor signal it is therefore proposed according to the present invention that storage of the arrival times of switching edges of crankshaft sensors 3 and camshaft sensors 5 respectively occur continuously so that a switchover between these two different sensor signals for calculating position pulses p or the status of position counter 11 is possible at any time fig7 shows the further processing of the arrival times stored in steps 200 to 400 of signals of crankshaft sensor 3.