An interface between base band circuitry and RF transceiver circuitry, particularly relating to the Bluetooth standard. The interface has a plurality of connectors (DBus) for controlling the RF transceiver circuitry including providing control information for changing the mode of operation of the transceiver, said modes including a transmit mode and a receive mode; at least first and second further connectors (RFBus) wherein in the transmit mode, one of said first and second connectors supplies data to the transceiver and the other is operable to perform a first function such as controlling the power amplifier in the RF circuitry and wherein, in the receive mode, one of said first and second connectors receives data from said RF module and the other is operable to perform a second function different from the first function.