Systems, methods, and apparatus are described that enable a serial bus to be operated in one or more modes that employ additional wires for communicating data. A method includes configuring a first interface to exchange data over two primary wires of a serial bus in accordance with a first I3C protocol, and configuring a second interface to communicate over at least one secondary wire in accordance with a second I3C protocol. In one example, the first data is encoded in a sequence of symbols representing signaling state of the two primary wires. A recovered clock signal may be derived from transitions between symbol transmission intervals in the first interface may be used to control double data rate communication through the second interface.