“…This method was extended to measure most I/O DC characteristics such as the output voltages and currents (VOL, IOL, VOH, IOH), the input voltage logic levels (VIL, VIH), and the pin leakage currents (IIL, IIH, IOZ) [9]. Additionally, the characterization of jitter and noise using I/O Loopback test has been proposed in [11], [12]. However, Loopback tests have a fault masking problem because the interface timing of inputs and outputs is measured jointly [13]; this would degrade the accuracy of testing.…”