A universal cable interface and associated system and method are provided for coupling a transmission medium to a processing device. The universal cable interface can selectively operate in a first (input) mode and a second (output) mode. The universal cable interface can also handle different types of data, such as standard definition video data and high definition video data. When operating in the first mode, the universal cable interface may receive serial data over the transmission medium and convert the serial data into a parallel format for transmission to the processing device. When operating in the second mode, the universal cable interface may receive parallel data from the processing device and convert the parallel data into a serial format for transmission over the transmission medium.