I2C Slave/master interface enhancement using state machines

Consistent with one example embodiment, communications systems, using a serial data transfer bus having a serial data line and a clock line used to implement a communications protocol, incorporate enhanced slave/master interfacing on an I2C bus using state machines. The communications system includes a first and second state-machine responsive to the rising edge of the clock signal, and a third state-machine, distinctly operational from the first and second state-machine, responsive to the falling edge of the clock signal. One of the first state-machine and the second state-machine conform to write states of the communications protocol, and the other of the first state-machine and the second state-machine conform to read states of the communications protocol.