Abstract: An integrated circuit configuration and a method monitor an integrated oscillator in the circuit. The oscillator has a minimum frequency and furnishes a synchronously controlling clock rate for the functioning of the integrated circuit when excited by an external frequency standard. An integrated reserve oscillator has a maximum frequency below the minimum frequency of the oscillator. An integrated frequency comparator is connected to the reserve oscillator and to the oscillator for comparing the frequency of the reserve oscillator with the frequency of the oscillator.

Abstract: An integrated semiconductor circuit which contains both a microprocessor as well as an analog-to-digital converter. Two D/A converters are allocated to an A/D converter. One of the D/A converters generates a internal base potential from an externally supplied fixed base potential and an externally supplied fixed reference potential under the direction of the microprocessor. The other one generates a internal reference potential from the two external potentials. The two internal potentials form the reference voltage which serves for the A/D conversion according to the principle of successive approximation. By so doing, the same circuit can be controlled by measuring points having different voltage ranges without the converter having to be provided with additional comparison stages. These are involved in comparison to the A/D conversion to be applied and serve the purpose of increasing the resolution.