System, methods and apparatus are described that facilitate transmission of data, particularly between two devices within an electronic apparatus. Data is selectively transmitted as N-phase polarity encoded symbols or as packets on differentially driven connectors. A data transfer method comprises encoding data and control signals in a sequence of symbols to be transmitted on a plurality of connectors, and transmitting the sequence of symbols on the plurality of connectors. Each symbol may be transmitted using a combination of a phase state of a first pair of connectors, a polarity of a second pair of connectors, and a selection of at least one undriven connector. Transmission of each symbol in the sequence of symbols may cause a change of state for at least one of the plurality of connectors.