Signal processing circuit and method for driving the same

A method for driving a signal processing circuit comprising a storage element, the storage element comprising a first inverter, a second inverter, a first selection transistor, a second selection transistor, a first transistor, a second transistor, a first capacitor, and a second capacitor, wherein each of the first transistor and the second transistor comprises an oxide semiconductor layer including a channel, wherein an input terminal of the first inverter is electrically connected to the input terminal of the storage element via the first selection transistor and the second transistor, wherein an output terminal of the first inverter is electrically connected to the output terminal of the storage element via the second selection transistor, wherein the output terminal of the first inverter is electrically connected to an input terminal of the second inverter via the first transistor, wherein an output terminal of the second inverter is electrically connected to the input terminal of the first inverter via the second transistor, wherein an electrode of the first capacitor is electrically connected to the input terminal of the second inverter, and wherein an electrode of the second capacitor is electrically connected to the input terminal of the first inverter, the method comprising the steps of:

• supplying a potential of data to an input terminal of the first inverter via the first selection transistor and the second transistor;
• outputting a potential of an output terminal of the first inverter as an output signal via the second selection transistor;
• supplying a potential of the output terminal of the first inverter to an input terminal of the second inverter via the first transistor;
• supplying a potential of an output terminal of the second inverter to the input terminal of the first inverter via the second transistor;
• and
• turning off the first transistor and the second transistor, before stopping the supply of the power-supply voltage to the first inverter and the second inverter.

A storage device comprising:

• a storage element comprising an input terminal, an output terminal, a first inverter, a second inverter, a first selection transistor, a second selection transistor, a first transistor, a second transistor, a first capacitor, and a second capacitor,
• wherein each of the first transistor and the second transistor comprises an oxide semiconductor layer including a channel,
• wherein an input terminal of the first inverter is electrically connected to the input terminal of the storage element via the first selection transistor and the second transistor,
• wherein an output terminal of the first inverter is electrically connected to the output terminal of the storage element via the second selection transistor,
• wherein the output terminal of the first inverter is electrically connected to an input terminal of the second inverter via the first transistor,
• wherein an output terminal of the second inverter is electrically connected to the input terminal of the first inverter via the second transistor,
• wherein an electrode of the first capacitor is electrically connected to the input terminal of the second inverter, and
• wherein an electrode of the second capacitor is electrically connected to the input terminal of the first inverter.