Method for checking the functionality of the computing unit

(57) Abstract: data word having a number of data bits which is determined beforehand in pre-determined time interval is supplied to the first computing unit from the second arithmetic unit, first calculation functionality of the method for inspecting unit is provided. One function is assigned to each data bit. A first calculation unit inverts the data bits belonging to the following process of the function and data words to the end of the time slot sent to the second computing unit, the second computing unit for checking the delivery data word.