Embodiments of the invention are generally directed to simultaneous transmission of clock and bidirectional data over a communication channel. An embodiment of a transmitting device includes a modulator to generate a modulated signal including a clock signal and a data signal, the clock signal being modulated by a first signal edge of the modulated signal and the data signal being modulated by a position of a second signal edge of the modulated signal; a driver to drive the modulated signal on a communication channel; an echo canceller to subtract reflected signals on the communication channel; and a data recovery module to recover a signal received on the communication channel, the received signal being encoded by Return-to-Zero (RZ) encoding, the signal being received simultaneously with driving the modulated signal on the communication channel.