A communication apparatus for communication according to a master-slave communication protocol is formed as a slave instance communicating with a master instance via a bus. The master instance is operative to switch the bus into a bus suspend state if no bus activity is present during a predetermined interval. In response to a bus suspend state, the slave instance makes a transition to a slave suspend state. The communication apparatus includes a monitor configured to monitor the bus activity and a transmitter configured to transmit a signal via the bus if the monitor does not recognize any bus activity during part of the predetermined interval and a transition of the slave instance to the slave suspend state is undesirable, wherein the signal is operative to prevent the master instance from switching the bus into the bus suspend state.