Arithmetic circuit and method of driving the same
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorKiyoshi Kato
Life of this patent
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Abstract
In order to reduce power consumption, an arithmetic circuit having a function of performing a logic operation processing based on an input signal, storing a potential set in accordance with the result of the logic operation processing as stored data, and outputting a signal with a value corresponding to the stored data as an output signal. The arithmetic circuit includes an arithmetic portion performing the logic operation processing, a first field-effect transistor controlling whether a first potential, which is the potential corresponding to the result of the logic operation processing is set, and a second field-effect transistor controlling whether the potential of the output signal data is set at a second potential which is a reference potential.
Claims19
A semiconductor device comprising:
- a first line to which a first power supply potential is applied;
- a first transistor that includes a first semiconductor layer including a first channel, the first channel including an oxide semiconductor, wherein a first terminal of the first transistor is electrically connected to the first line;
- a second transistor that includes a second semiconductor layer including a second channel, the second channel including an oxide semiconductor, wherein a first terminal of the second transistor is electrically connected to a second terminal of the first transistor;
- a circuit electrically connected to a second terminal of the second transistor;
- and
- a second line to which a second power supply potential is applied, the second line electrically connected to the circuit,
- wherein the circuit is configured to control whether the second terminal of the second transistor and the second line are brought into conduction or not, and
- wherein each of the first channel and the second channel comprises c-axis aligned crystals of the oxide semiconductor.
An arithmetic circuit configured to perform a logic operation processing based on an input signal, to store a potential corresponding to a result of the logic operation processing as stored data, and to output a signal with a value corresponding to the stored data as an output signal, the arithmetic circuit comprising:
- an arithmetic portion performing the logic operation processing;
- a first field-effect transistor controlling whether a potential of the stored data is set at the potential corresponding to the result of the logic operation processing or not;
- and
- a second field-effect transistor controlling whether the potential of the stored data is set at a reference potential,
- wherein an off-state current per micrometer of channel width of each of the first and second field-effect transistors is lower than or equal to 10 aA, and
- wherein each of a first channel of the first field-effect transistor and a second channel of the second field-effect transistor comprises c-axis aligned crystals of an oxide semiconductor.
Dependencies are inferred from the claim text.