Abstract: Synchronization of a bus master to a bus slave permits the desired hierarchical structuring of buses by virtue of a bus slave on a bus receiving the synchronization information for an associated bus master is disclosed. A phase locked loop is used to filter this clock information and to regenerate missing clock pulses. This clock which is now “sound,” is supplied to one or more parallel bus masters of other buses, which generate the corresponding clock information using the necessary messages on the respective bus. This principle is independent of the respective bus system, which means that a plurality of identical buses or else different bus systems can be operated hierarchically in synchronization with one another.