Abstract: A method for reducing power consumption of a source driver included in a display device and suppressing heat generation is provided. In a display device in which each pixel is supplied with a data signal of image data through a source line, a source driver is included, each source line is electrically connected to the source driver, and the source driver has a function of driving the source lines. In the case where the amount of change of the data signal of the image data is small, in other words, in the case where power for charging and discharging the source line can be small, the source driver reduces the apparent size of the transistor at the output stage, and power consumption can be reduced. Furthermore, the amount of heat generation can be reduced.

Abstract: The display evenness of a large or high-resolution display device is improved. The display device includes a source driver, a first gate driver, a second gate driver, a first pixel, and a second pixel. The first pixel is electrically connected to the source driver and the first gate driver. The second pixel is electrically connected to the source driver and the second gate driver. The first pixel is located closer to the source driver than the second pixel is. The first gate driver has a function of supplying a first write signal to the first pixel. The second gate driver has a function of supplying a second write signal to the second pixel. The pulse width of the second write signal is larger than the pulse width of the first write signal.

Abstract: Provided is a structure which is capable of central control of an electric device and a sensor device and a structure which can reduce power consumption of an electric device and a sensor device. A central control system includes at least a central control device, an output unit, and an electric device or a sensor device. The central control device performs arithmetic processing on information transmitted from the electric device or the sensor device and makes the output unit output information obtained by the arithmetic processing. It is possible to know the state of the electric device or the sensor device even apart from the electric device or the sensor device. The electric device or the sensor device includes a transistor which includes an activation layer using a semiconductor with the band gap wider than that of single crystal silicon.

Abstract: A semiconductor device in which an increase in the degree of wiring congestion due to an increase in the number of output terminals of a driver IC can be reduced is provided. In a shift register of the driver IC, pulse signals are sequentially output in different directions. For example, pulse signal output circuits are provided so as to sequentially output pulse signals in ascending order from right to left and then sequentially output pulse signals in ascending order from left to right. With such a structure, output signals of the driver IC can be output not only from a side opposite to a side along which an input terminal is provided, but also from a side along which the input terminal is provided; thus, the number of output terminals can be increased without an increase in the degree of wiring congestion.

Abstract: A display device that can be easily and more flexibly designed is provided. The display device includes a pixel circuit and a driver circuit in a display portion. The driver circuit includes a plurality of pulse output circuits. Each of the plurality of pulse output circuits has a function of driving a gate line. The pixel circuit is electrically connected to the gate line. Each of the plurality of pulse output circuits includes a first transistor. The pixel circuit includes a second transistor. A layer including the second transistor is over a layer including the first transistor, and the first transistor and the second transistor overlap with each other.

Abstract: A display device with favorable display quality is provided. A display portion where a plurality of pixels is arranged in a matrix is divided into Region A and Region B, i.e., regions on the upstream side and the downstream side of a scanning direction. A signal line for supplying an image signal is provided in each of Region A and Region B. Region A and Region B adjoin each other such that a boundary line showing the boundary between the regions is bent. Bending the boundary line suppresses formation of a stripe in a boundary portion. For example, in a given column, the total number of pixels electrically connected to a signal line in Region A is made different from the total number of pixels electrically connected to a signal line in Region B.

Abstract: An imaging device capable of image processing is provided. The imaging device can retain analog data (image data) obtained by an image-capturing operation in a pixel and perform a product-sum operation of the analog data and a predetermined weight coefficient in the pixel to convert the data into binary data. When the binary data is taken in a neural network or the like, processing such as image recognition can be performed. Since enormous volumes of image data can be retained in pixels in the state of analog data, processing can be performed efficiently.

Abstract: A semiconductor device in which a transistor has the characteristic of low off-state current is provided. The transistor comprises an oxide semiconductor layer having a channel region whose channel width is smaller than 70 nm. A temporal change in off-state current of the transistor over time can be represented by Formula (a2). In Formula (a2), IOFF represents the off-state current, t represents time during which the transistor is off, ? and ? are constants, ? is a constant that satisfies 0<??1, and CS is a constant that represents load capacitance of a source or a drain.

Abstract: The display device includes a pixel and a driver circuit. The driver circuit includes a receiving circuit, a controller, a switching control circuit, and a signal generation circuit. The receiving circuit outputs image data obtained by converting differential signals into parallel data to the controller. The receiving circuit includes a plurality of circuits each including a first amplifier and a second amplifier. The first amplifier and the second amplifier each include a switch and a first transistor for supplying a bias current. The switch has a function of controlling electrical continuity between a wiring for supplying a bias voltage and a gate of the first transistor. The switching control circuit has a function of outputting a switching signal for controlling electrical continuity of the switch.

Abstract: Provided is a structure which is capable of central control of an electric device and a sensor device and a structure which can reduce power consumption of an electric device and a sensor device. A central control system includes at least a central control device, an output unit, and an electric device or a sensor device. The central control device performs arithmetic processing on information transmitted from the electric device or the sensor device and makes the output unit output information obtained by the arithmetic processing. It is possible to know the state of the electric device or the sensor device even apart from the electric device or the sensor device. The electric device or the sensor device includes a transistor which includes an activation layer using a semiconductor with the band gap wider than that of single crystal silicon.

Abstract: An object is to provide a semiconductor device that can maintain the connection relation between logic circuit units or the circuit configuration of each of the logic circuit units even after supply of power supply voltage is stopped. Another object is to provide a semiconductor device in which the connection relation between logic circuit units or the circuit configuration of each of the logic circuit units can be changed at high speed. In a reconfigurable circuit, an oxide semiconductor is used for a semiconductor element that stores data on the circuit configuration, connection relation, or the like. Specifically, the oxide semiconductor is used for a channel formation region of the semiconductor element.

Abstract: A display device that can be easily and more flexibly designed is provided. The display device includes a pixel circuit and a driver circuit in a display portion. The driver circuit includes a plurality of pulse output circuits. Each of the plurality of pulse output circuits has a function of driving a gate line. The pixel circuit is electrically connected to the gate line. Each of the plurality of pulse output circuits includes a first transistor. The pixel circuit includes a second transistor. A layer including the second transistor is over a layer including the first transistor, and the first transistor and the second transistor overlap with each other.

Abstract: A semiconductor device in which a transistor has the characteristic of low off-state current is provided. The transistor comprises an oxide semiconductor layer having a channel region whose channel width is smaller than 70 nm. A temporal change in off-state current of the transistor over time can be represented by Formula (a2). In Formula (a2), IOFF represents the off-state current, t represents time during which the transistor is off, ? and ? are constants, ? is a constant that satisfies 0<??1, and CS is a constant that represents load capacitance of a source or a drain.

Abstract: A method for reducing power consumption of a source driver included in a display device and suppressing heat generation is provided. In a display device in which each pixel is supplied with a data signal of image data through a source line, a source driver is included, each source line is electrically connected to the source driver, and the source driver has a function of driving the source lines. In the case where the amount of change of the data signal of the image data is small, in other words, in the case where power for charging and discharging the source line can be small, the source driver reduces the apparent size of the transistor at the output stage, and power consumption can be reduced. Furthermore, the amount of heat generation can be reduced.

Abstract: An object is to provide a semiconductor device that can maintain the connection relation between logic circuit units or the circuit configuration of each of the logic circuit units even after supply of power supply voltage is stopped. Another object is to provide a semiconductor device in which the connection relation between logic circuit units or the circuit configuration of each of the logic circuit units can be changed at high speed. In a reconfigurable circuit, an oxide semiconductor is used for a semiconductor element that stores data on the circuit configuration, connection relation, or the like. Specifically, the oxide semiconductor is used for a channel formation region of the semiconductor element.

Abstract: Display quality is improved. A display device includes a display controller and a display panel provided with m×n pixels. The display controller includes the step of comparing first display data, which is displayed in a first pixel connected to the i-th signal line and the (j?1)-th scan line, with second display data, which is displayed in a second pixel connected to the i-th signal line and the j-th scan line, and calculating an absolute value of a difference value, the step of extracting a maximum value from a result of the absolute value, and the step of determining a first selection period of the j-th scan line in accordance with the maximum value.

Abstract: Objects are to provide a semiconductor device with a novel structure, to provide a semiconductor device with low power consumption, and to provide a semiconductor device with a small chip area. A digital-analog converter and a frame memory are included. The frame memory includes a sample-and-hold circuit, a correction circuit, and a source follower circuit. The sample-and-hold circuit retains the analog voltage output from the digital-analog converter. The correction circuit corrects the analog voltage retained in the sample-and-hold circuit. The source-follower circuit outputs the corrected analog voltage. The sample-and-hold-circuit, the correction circuit, and the source follower circuit each comprise a first transistor. The first transistor comprises an oxide semiconductor layer in a semiconductor layer.

Abstract: To achieve versatility, a driver IC has a function of generating an analog data signal from an image signal input from the outside; a function of outputting the analog data signal from an output pin; and a function of setting the analog data signal as a data signal for alternating-current driving or for direct-current driving, in accordance with data of a digital signal input from the outside. For example, the driver IC can output data signals for alternating-current driving from output pins in odd-numbered columns and data signals for direct-current driving from output pins in even-numbered columns. Furthermore, the driver IC can output data signals for alternating-current driving or for direct-current driving from all the output pins. The driver IC can drive a liquid crystal panel, a self-luminous panel, and a hybrid display panel where one subpixel includes a liquid crystal element and a light-emitting element.

Abstract: A microcontroller which operates in a low power consumption mode is provided. A microcontroller includes a CPU, a memory, and a peripheral circuit such as a timer circuit. A register in the peripheral circuit is provided in an interface with a bus line. A power gate for controlling supply control is provided. The microcontroller can operate not only in a normal operation mode where all circuits are active, but also in a low power consumption mode where some of the circuits are active. A volatile memory and nonvolatile memory are provided in a register, such as a register of the CPU. Data in the volatile memory is backed up in the nonvolatile memory before the power supply is stopped. In the case where the operation mode returns to the normal mode, when power supply is started again, data in the nonvolatile memory is written back into the volatile memory.

Abstract: A source line through which a video signal is transmitted also serves as a driving electrode of a touch sensor. To perform display, a video signal is transmitted to the source line. To sense the touch, a driving signal is transmitted to the source line. A circuit for transmitting the video signal and the driving signal to the source line has a structure in which a period for transmitting the driving signal is added in the wiring through which the digital video signal is transmitted and the output to the source line is switched by using a switching circuit. Alternatively, the circuit has a structure in which a period for transmitting the driving signal is added in a wiring through which a latch signal is transmitted and the output to the source line is switched.