A method of detecting a cable connected to a first device includes generating a second signal within the first device, and outputting the second signal onto an input-only pin of a cable connector on the first device, wherein the input-only pin is assigned to receive a first signal from a driver on a second device when a cable is connected from the second device to the cable connector, and wherein the second signal has a frequency that is at least four times greater than the frequency of the first signal. The method further comprises determining that a cable is not connected to the cable connector in response to detecting the second signal on a wire coupled to the input-only pin, and determining that the cable is connected to the cable connector in response to detecting a signal other than the second signal.