Abstract: Oscillator circuitry is disclosed. The oscillator circuitry comprises a free-running oscillator for generating pulses at a frequency, and a frequency adjustment circuit for adaptively adjusting the frequency of the free-running oscillator. The frequency adjustment circuit comprises a counter configured to count a number of pulses generated by the free-running oscillator and logic configured to compare the number of pulses with an expected number of pulses (corresponding to a target frequency) to determine a difference value and to adjust the frequency of the free-running oscillator in dependence on the difference value. The frequency adjustment circuit is configured, in response to receiving a synchronisation pulse, to trigger an update of the number of pulses to be compared.

Abstract: Oscillator circuitry is disclosed. The oscillator circuitry comprises a free-running oscillator for generating pulses at a frequency, and a frequency adjustment circuit for adaptively adjusting the frequency of the free-running oscillator. The frequency adjustment circuit comprises a counter configured to count a number of pulses generated by the free-running oscillator and logic configured to compare the number of pulses with an expected number of pulses (corresponding to a target frequency) to determine a difference value and to adjust the frequency of the free-running oscillator in dependence on the difference value. The frequency adjustment circuit is configured, in response to receiving a synchronisation pulse, to trigger an update of the number of pulses to be compared.

Abstract: Provided is a method and an apparatus for detecting an operating state or a change in an operating state in a system in which at least one analog signal indicating the operating state is present. The method includes sampling of the analog signal or of a signal dependent on the analog signal for the purpose of providing a sampling signal. The method also includes generation of a transformation signal representing a spectral distribution from a number of signal values of the sampling signal, and comparison of the transformation signal with at least one reference signal representing a spectral distribution.

Abstract: Provided is a method and an apparatus for detecting an operating state or a change in an operating state in a system in which at least one analog signal indicating the operating state is present. The method includes sampling of the analog signal or of a signal dependent on the analog signal for the purpose of providing a sampling signal. The method also includes generation of a transformation signal representing a spectral distribution from a number of signal values of the sampling signal, and comparison of the transformation signal with at least one reference signal representing a spectral distribution.