Methods and systems are described for reading from or writing to a plurality of slave devices connected to a communications bus having a common data line. The slave devices are mapped to a virtual device address and the communication is initiated by the master by signaling a start condition and the virtual device address. Each of the slave devices mapped to the virtual device address identifies a register in that slave device associated with the virtual device address and, in sequence, performs a read or write operation on the bus with regard to its identified register in a respective predetermined time slot within the communication or to a corresponding virtual register address assigned to the slave device previously.