Abstract: A semiconductor device with a large storage capacity per unit area is provided. The disclosed semiconductor device includes a plurality of gain-cell memory cells each stacked over a substrate. Axes of channel length directions of write transistors of memory cells correspond to each other, and are substantially perpendicular to the top surface of the substrate. The semiconductor device can retain multi-level data. The channel of read transistors is columnar silicon (embedded in a hole penetrating gates of the read transistors). The channel of write transistors is columnar metal oxide (embedded in a hole penetrating the gates of the read transistors and gates, or write word lines, of the write transistors). The columnar silicon faces the gate of the read transistor with an insulating film therebetween. The columnar metal oxide faces the write word line with an insulating film, which is obtained by oxidizing the write word line, therebetween, and is electrically connected to the gate of the read transistor.

Abstract: An imaging device with reduced power consumption is provided. The imaging device includes an imaging portion and an encoder. First image data obtained by the imaging portion is transmitted to the encoder. The encoder includes a first circuit that forms a neural network, and the first circuit conducts feature extraction by the neural network on a first image to generate second image data. Note that since the first circuit has a function of performing convolution processing using a weight filter, the encoder can perform computation with a convolutional neural network.

Abstract: An electronic device capable of gaze tracking is provided. The electronic device includes a display apparatus, an image processing portion, and a control portion. The display apparatus includes a light-emitting device and a light-receiving device. The light-emitting device has a function of emitting light to a user's eye as a display image. The light-receiving device has a function of capturing a retina of the user's eye as a captured image. The image processing portion has a function of detecting a macula included in the retina from the captured image and a function of calculating position data of the macula. The control portion has a function of obtaining a position of a user's gaze destination on the display image from the position data of the macula.

Abstract: An electronic device that enables smooth communication is provided. The electronic device includes a display portion including a first camera; a second camera; and an image processing portion. The second camera is positioned in a region not overlapping with the display portion. The first camera has a function of generating a first image of a subject, and the second camera has a function of generating a second image of the subject. The image processing portion includes a generator that performs learning using training data. The training data includes an image including a person's face. The image processing portion has a function of making the first image clear when the first image is input to the generator and a function of tracking the gaze of the subject on the basis of the second image.

Abstract: To provide a novel electronic device. The electronic device includes a housing and a display device. The display device includes a first layer, a second layer, and a third layer. The first layer, the second layer, and the third layer are provided in different layers. The first layer includes a driver circuit and an arithmetic circuit. The second layer includes pixel circuits and a cell array. The third layer includes light-receiving devices and light-emitting devices. The pixel circuits each have a function of controlling light emission of the light-emitting device. The driver circuit has a function of controlling the pixel circuits. The arithmetic circuit has a function of performing arithmetic processing on the basis of first data corresponding to currents output from the light-receiving devices and second data corresponding to a potential held in the cell array.

Abstract: A high-resolution display apparatus having a light detection function is provided. The display apparatus includes a display portion in which a first arrangement pattern and a second arrangement pattern are repeatedly placed in a first direction. In the first arrangement pattern, a first subpixel and a second subpixel are repeatedly arranged in a second direction. In the second arrangement pattern, a third subpixel, a fourth subpixel, and a fifth subpixel are repeatedly arranged in the second direction. Each of the first subpixel to the fourth subpixel includes a light-emitting device. The fifth subpixel includes a light-receiving device. Three or all of light-emitting devices included in the four subpixels can include EL layers with the same structure.

Abstract: A semiconductor device including a display pixel circuit and an imaging pixel circuit is provided. The semiconductor device includes first and second circuits; the first circuit includes a light-emitting device; and the second circuit includes a light-receiving device, first to fifth transistors, and a first capacitor. The light-receiving device includes first and second terminals, and the light-emitting device includes third and fourth terminals. A first terminal of the first transistor is electrically connected to a first terminal of the second transistor, and a gate of the second transistor is electrically connected to a first terminal of the third transistor and a first terminal of the first capacitor. A second terminal of the first capacitor is electrically connected to a first terminal of the fourth transistor and a first terminal of the fifth transistor.

Abstract: A solid-state imaging device with high productivity and improved dynamic range is provided. In the imaging device including a photoelectric conversion element having an i-type semiconductor layer, functional elements, and a wiring, an area where the functional elements and the wiring overlap with the i-type semiconductor in a plane view is preferably less than or equal to 35%, further preferably less than or equal to 15%, and still further preferably less than or equal to 10% of the area of the i-type semiconductor in a plane view. Plural photoelectric conversion elements are provided in the same semiconductor layer, whereby a process for separating the respective photoelectric conversion elements can be reduced. The respective i-type semiconductor layers in the plural photoelectric conversion elements are separated by a p-type semiconductor layer or an n-type semiconductor layer.

Abstract: A semiconductor device with reduced circuit area is provided. The semiconductor device includes first and second cell arrays and a first converter circuit. The first cell array includes a first cell and a second cell in the same row, and the second cell array includes third and fourth cells in the same row. The first cell is electrically connected to first and second wirings, the second cell is electrically connected to the first and third wirings, the third cell is electrically connected to fourth and sixth wirings, and the fourth cell is electrically connected to fifth and seventh wirings. The sixth wiring is electrically connected to the seventh wiring. The first to fourth cells each have a function of outputting current corresponding to a product of retained data and input data. Specifically, the first cell, the second cell, the third cell, and the fourth cell output current to the second wiring, the third wiring, the sixth wiring, and the seventh wiring, respectively.

Abstract: A semiconductor device with a novel structure is provided. The semiconductor device includes a cell array performing a product-sum operation of a first layer and a product-sum operation of a second layer in an artificial neural network, a first circuit from which first data is input to the cell array, and a second circuit to which second data is output from the cell array. The cell array includes a plurality of cells. The cell array includes a first region and a second region. In a first period, the first region is supplied with the t-th (t is a natural number greater than or equal to 2) first data from the first circuit and outputs the t-th second data according to the product-sum operation of the first layer to the second circuit. In the first period, the second region is supplied with the (t+1)-th first data from the first circuit and outputs the (t+1)-th second data according to the product-sum operation of the second layer to the first circuit.

Abstract: An electronic device having an eye tracking function is provided. The electronic device includes a display device and an optical system. The display device includes a first light-emitting element, a second light-emitting element, a sensor portion, and a driver circuit portion. The sensor portion includes a light-receiving element. The first light-emitting element has a function of emitting infrared light or visible light. The second light-emitting element has a function of emitting light of a color different from that of light emitted from the first light-emitting element. When the first light-emitting element emits infrared light, the light-receiving element has a function of detecting the infrared light that is emitted from the first light-emitting element and reflected by an eyeball of a user.

Abstract: A novel semiconductor device is provided. In reservoir computing using an input layer, a reservoir layer, and an output layer, variation in threshold voltage between transistors is used as a weight used for product arithmetic processing. Two transistors are provided in one product arithmetic circuit and data u is supplied to gates of the two transistors. Drain current of each of the transistors is determined by the data u and the threshold voltage of the transistor. The difference between the drain currents corresponds to a product arithmetic result. The difference between the drain currents is converted into voltage to be output. A plurality of product arithmetic circuits are connected in parallel to form a product-sum arithmetic circuit.

Abstract: A semiconductor device that restores degraded data is provided. The semiconductor device includes a first circuit, a storage portion, and an arithmetic portion. The first circuit includes a current source and a first switch. The storage portion includes a first transistor and a first capacitor. The arithmetic portion includes a second transistor. A first terminal of the first transistor is electrically connected to a control terminal of the first switch, a first terminal of the first switch is electrically connected to an output terminal of the current source, and a second terminal of the first switch is electrically connected to a first terminal of the second transistor. When data retained in the arithmetic portion is restored, the first transistor is turned on, and the data retained in the storage portion is supplied to the control terminal of the first switch through the first transistor.

Abstract: A display apparatus having a novel structure is provided. A plurality of display panels, a fixing member having a curved surface, and a housing storing the fixing member are included. The display panel includes a display portion including a pixel circuit, a non-display portion provided to surround the display portion, a gate driver circuit for driving the pixel circuit, and a source driver circuit. The gate driver circuit is provided at a position overlapping with the display portion. The source driver circuit is provided at a position overlapping with the non-display portion. The plurality of display panels are fixed along the curved surface of the fixing member.

Abstract: A neuron circuit can switch between two functions: as an input neuron circuit, and as a hidden neuron circuit. An error circuit can switch between two functions: as a hidden error circuit, and as an output neuron circuit. A switching circuit is configured to be capable of changing the connections between the neuron circuit, a synapse circuit, and the error circuit. The synapse circuit includes an analog memory that stores data that corresponds to the connection strength between the input neuron circuit and the hidden neuron circuit or between the hidden neuron circuit and the output neuron circuit, a writing circuit that changes the data in the analog memory, and a weighting circuit that weights an input signal in reaction to the data of the analog memory and outputs the weighted output signal. The analog memory includes a transistor comprising an oxide semiconductor with extremely low off-state current.

Abstract: A driving method of a semiconductor device that takes three-dimensional images with short duration is provided. In a first step, a light source starts to emit light, and first potential corresponding to the total amount of light received by a first photoelectric conversion element and a second photoelectric conversion element is written to a first charge accumulation region. In a second step, the light source stops emitting light and second potential corresponding to the total amount of light received by the first photoelectric conversion element and the second photoelectric conversion element is written to a second charge accumulation region. In a third step, first data corresponding to the potential written to the first charge accumulation region is read. In a fourth step, second data corresponding to the potential written to the second charge accumulation region is read.

Abstract: An occupant protection device which can protect an occupant without delay is provided. An image taken by an imaging device is analyzed to judge whether there is an object approaching the subject car. In the case where a collision between the object and the subject car is judged to be inevitable, an airbag device is activated before the collision, whereby the occupant can be protected without delay. By using selenium for a light-receiving element of the imaging device, an accurate image can be obtained even under low illuminance. Imaging in a global shutter system leads to an accurate image with little distortion. This enables more accurate image analysis.

Abstract: To provide an operation method of a semiconductor device in which a variation in arithmetic operation results is reduced. The semiconductor device includes first and second cell arrays and first to fifth circuits. First, third standard data is written from the fourth circuit to the second cell array, and first standard data is written from the first circuit to the first cell array. Then, second standard data is transmitted from the second circuit to the first cell array, a result of a product-sum operation of the first standard data and the second standard data is input from the first cell array to the third circuit, and fourth standard data corresponding to the result of the product-sum operation is transmitted from the third circuit to the second cell array.

Abstract: A semiconductor device that can perform product-sum operation with low power consumption is provided. The semiconductor device includes first and second circuits; the first circuit includes a first holding node and the second circuit includes a second holding node. The first circuit is electrically connected to first and second input wirings and first and second wirings, the second circuit is electrically connected to the first and second input wirings and the first and second wirings, and the first and second circuits each have a function of holding first and second potentials corresponding to first data at the first and second holding nodes. When a potential corresponding to second data is input to each of the first and second input wirings, the first circuit outputs a current to one of the first wiring and the second wiring and the second circuit outputs a current to the other of the first wiring and the second wiring.

Abstract: An electronic device having an eye tracking function is provided. The electronic device includes a display device and an optical system. The display device includes a first light-emitting element, a second light-emitting element, a sensor portion, and a driver circuit portion. The sensor portion includes a light-receiving element. The first light-emitting element has a function of emitting infrared light or visible light. The second light-emitting element has a function of emitting light of a color different from that of light emitted from the first light-emitting element. When the first light-emitting element emits infrared light, the light-receiving element has a function of detecting the infrared light that is emitted from the first light-emitting element and reflected by an eyeball of a user.