The invention relates to an integrated circuit having a system base chip of the kind usually provided for performing transmitting and/or receiving functions at a node that is coupled to a vehicle data bus. In an example embodiment, there is an integrated circuit having a system base chip that has basic functions for a transmitting and/or receiving system for a vehicle data bus, namely at least a system voltage supply, a system reset and a monitoring function An interface circuit that, in a self-contained fashion, runs at least parts of a data bus protocol, and in particular, the LIN (Local Interconnect Network) protocol, that performs detection of the bit-rate of received data, and that is capable of passing on at least one received or transmitted byte. A serial/parallel converter makes use in its conversion of the bit-rate detected by the interface circuit.