Semiconductor device, CPU, image processing circuit and electronic device, and driving method of semiconductor device

摘要

The invention provides a semiconductor device which consumes less power in pending. The invention further provides a semiconductor device in which a gate electrode is provided over both sides of a semiconductor thin film which forms a transistor, a logic signal is applied to a first gate electrode, a threshold value control signal is applied to a second gate electrode, and a threshold value of a transistor which forms the semiconductor device is controlled by a potential of the second gate electrode, and a driving method thereof. Then, the invention provides a semiconductor device provided with a plurality of logic circuits formed of such a transistor with a back gate and a driving method thereof.