a method for bi - directional transmission of data between a source and a sink over a two - wire interface includes re - mapping a data signal and a clock signal from a first local bus on the source into a different protocol signal . transmitting the different protocol signal from the source to the sink over the two - wire interface . re - mapping the different protocol signal back into the data signal and the clock signal for use on a second local bus on the sink . re - mapping the data signal and the clock signal from the second local bus into the different protocol signal ; and transmitting the different protocol signal from the sink to the source over the two - wire interface .