Patent ID: 8594166

Claim:
A system for the bidirectional synchronous transmission of data between a device to be tested and a testing device comprising: a device to be tested and a testing device which are connected together by an electric transmission line and by an electric ground line, wherein the device to be tested and the testing device are suitable for sending and receiving data synchronously with a predetermined clock frequency and phase as sequences of first and second voltages which respectively represent a first and second value of a bit on the electric transmission line, wherein to receive the data the testing device samples a voltage on the electric transmission line at predetermined sampling phases of the clock to identify whether the first or the second voltage is present, wherein to send the data the device to be tested produces the sequences of first and second voltages in such a way that the first or the second voltage is present on the electric transmission line in a phase range of at least −20° through +20° of the predetermined sampling phases of the receiving device, wherein the clock frequency and phase is predetermined by the device to be tested and the testing device is synchronized to said predetermined clock frequency and phase, and wherein in an initialization phase the device to be tested transmits a sequence of alternate first and second voltages on the electric transmission line and the testing device derives the clock frequency and phase from said sequence.