Abstract: The data communication system includes a first control device, a second data device and a data link, including a first transmission link and a second transmission link, between the second data device and the first control device. A data driver enables data transmission from the second data device to the first control device across the data link, and a differential controller is adapted to generate a voltage differential between the first transmission link and the second transmission link. A detector detects differences in voltage levels between the first transmission link and the second transmission link. The data communication system enables bi-directional communication between integrated circuit devices over a serial communication link avoiding the necessity for clock, chip enable and control connections on the data device and is particularly useful for communication between an image sensor and coprocessor.