| abstract |
An object of the present invention is to reduce the leakage current of a transistor so that failure of a logic circuit can be suppressed. The logic circuit includes a transistor including an oxide semiconductor layer having a function of a channel forming layer and having an off current of 1 x 10 < -13 > A or less per channel width micrometer. A first signal, a second signal, and a third signal, which is a clock signal, are input as input signals. A fourth signal and a fifth signal, whose voltage states are set according to the input first to third signals, are output as output signals. |