Methods and apparatus are described relating to an electronic device which includes at least one configurable resistive element. Each such configurable resistive element includes at least one multi-layer thin film element exhibiting giant magnetoresistance. The resistance value of each configurable resistive element is configurable over a resistance value range by application of at least one magnetic field which manipulates at least one magnetization vector associated with the thin film element. One embodiment is an adjustable output gate. Another embodiment is a differential amplifier in which the gain of each channel is adjustable.