Methods, apparatus, and systems for data communication over a multi-wire, multi-phase interface are disclosed. A method of calibration includes configuring a 3-phase signal to include a high frequency component and a low frequency component during a calibration period, and transmitting a version of the 3-phase signal on each wire of a 3-wire interface. The version of the 3-phase signal transmitted on each wire is out-of-phase with the versions of the 3-phase signal transmitted on each of the other wires of the 3-wire interface. The 3-phase signal may be configured to enable a receiver to determine certain operating parameters of the 3-wire interface.