To effect redundant signal processing of a safety-relevant application, such as for a safety control unit of a motor vehicle, at least two redundant signals are fed from at least one sensor to an electronic circuit assembly as input signals for processing. At least one input signal is converted into a different test signal. In the electronic circuit assembly, the input signals are fed to a first peripheral module of a microcontroller, and the test signal is fed to an additional peripheral module. The sensor information of the input signals and of the test signal are thus redundantly processed independently of each other in a respective peripheral module of the microcontroller.