Patent ID: 7366623

Claim:
A method for characterizing a load on a data line; the method comprising the steps of: (a) applying a first voltage to said data line; said first voltage having a first voltage value with respect to a reference voltage value; (b) measuring a first current value on said data line while said first voltage is applied to said data line; (c) applying a second voltage to said data line; said second voltage having a second voltage value displaced a first voltage interval from said first voltage value away from said reference voltage value; (d) measuring a second current value on said data line while said second voltage is applied to said data line; (e) comparing said second current value with said first current value to determine a first impedance value for said data line; (f) applying a third voltage to said data line; said third voltage having a third voltage value displaced a second voltage interval from said second voltage value toward said reference voltage value; (g) measuring a third current value on said data line while said third voltage is applied to said data line; and (h) comparing said third current value with at least one of said first current value and said second current value to determine whether a hysteretic impedance change occurs when voltage on said data line is varied.