Abstract: A method for characterizing a load on a data line includes the steps of: (A) Applying at least three successive voltages to the data line. Each respective odd-numbered successive voltage of the at least three successive voltages has substantially a first voltage value displaced a first voltage interval from a reference voltage value. Each respective even-numbered successive voltage of the at least three successive voltages has substantially a second voltage value displaced a second voltage interval from the reference voltage value. (B) Measuring a respective current value on the data line while each of the at least three successive voltages is applied to the data line. (C) Comparing the respective current values for selected successive voltages of the at least three successive voltages to determine whether a hysteric impedance change occurs when voltage on the data line is varied.