Systems, methods and apparatus are described that facilitate transmission of data between two devices within an electronic apparatus. A data transfer method includes receiving from a three-wire interface, a first packet of data encoded in a first sequence of symbols representing transitions in signaling state of the three wires, and transmitting on the three-wire interface, a second packet of data encoded in a second sequence of symbols representing transitions in signaling state of the three wires. The first sequence of symbols may include up to five types of symbol. The second sequence of symbols may include two or three types of symbol.