a system having a transmission unit transmitting an output data signal formed from output data and related error detection code and a corresponding receiving unit . the output data signal is pre - emphasized by a pre - emphasis driver in the transmission unit . the receiving unit includes an equalizer equalizing the received output data signal and an error detector analyzing the error detection code to determine whether a bit error is present in the received data . upon successive data transmission failures either an equalization coefficient in the equalizer or a pre - emphasis coefficient in the pre - emphasis driver are changed .