Abstract: A novel electronic device including a reconfigurable circuit is provided. In the electronic device including a reconfigurable circuit capable of executing multi-context operation, a context selection signal is locally generated. For example, a context selection signal is generated in the reconfigurable circuit with the use of context determination data contained in an output of another logic block, for example. The range of application of the context selection signal can be set as appropriate by a user. Thus, multi-context operation performed locally and partly enables efficient use of the circuit. Memory usage can be reduced and its efficiency can be improved compared to the case of using global multi-context driving. Other embodiments may be disclosed and claimed.

Abstract: A decoder with reduced power consumption is provided. The decoder includes a first circuit and a second circuit for holding data. The second circuit includes a first transistor, a second transistor, and a third transistor. The first transistor and the second transistor include an oxide semiconductor in a channel formation region. The third transistor includes silicon in a channel formation region. A gate of the second transistor is electrically connected to one of a source and a drain of the first transistor and a gate of the third transistor is electrically connected to one of a source and a drain of the second transistor. The decoder is configured to provide or stop power supply to the semiconductor device depending on a packet ID of a header portion of the data and to perform data storing or restoring of data between the first circuit and the second circuit.

Abstract: A semiconductor device that is suitable for high-speed operation is provided. The semiconductor device includes a decoder. The decoder includes a first circuit. The first circuit is configured to operate in synchronization with a clock signal. The first circuit is configured to perform image processing. A circuit configuration of the first circuit can be changed. Clock gating is performed on the first circuit to prevent the clock signal from being input to the first circuit when the circuit configuration of the first circuit is being changed. A broadcasting system including the semiconductor device is also provided.

Abstract: A semiconductor device that can operate normally with lower power consumption is provided. The semiconductor device includes a pair of first circuits which each include a first transistor and a second transistor capable of controlling the supply of a first signal to a gate of the first transistor, and a second circuit which is capable of generating a second signal which is to be supplied to a gate of the second transistor and which has a larger amplitude than the first signal. One of a source and a drain of one of the first transistors included in the pair of first circuits is electrically connected to one of a source and a drain of the other of the first transistors. The first signals supplied to the gates of the first transistors in the pair of first circuits have potentials with different logic levels.

Abstract: A novel semiconductor device is provided. The semiconductor device includes a programmable logic device including a programmable logic element, a control circuit, and a detection circuit. The programmable logic device includes a plurality of contexts. The control circuit is configured to control selection of the contexts. The detection circuit is configured to output a signal corresponding to the amount of radiation. The control circuit is configured to switch between a first mode and a second mode in accordance with the signal corresponding to the amount of radiation. The first mode is a mode in which the programmable logic device performs processing by a multi-context method, and the second mode is a mode in which the programmable logic device performs processing using a majority signal of signals output from the logic element multiplexed by the plurality of contexts.

Abstract: A small semiconductor device is provided. The semiconductor device includes a register, switches, a memory circuit, a controller, and a display. An output terminal of the register is electrically connected to two or more of the switches. The switches are electrically connected to the memory circuit. The register has a function of retaining data corresponding to a parameter used when the controller operates. The switches have a function of selecting the memory circuit to which the data retained in the register is to be output. The memory circuit has a function of retaining the data output from the register. The controller has a function of reading the data retained in the memory circuit to control operation of the display.

Abstract: A display system is provided. The display system includes an imaging device, a processing device, and a display device that includes first and second display elements. The imaging device has a function of supplying imaging data based on a captured image. The processing device has a function of receiving the imaging data, supplying first image data containing at least part of the captured image, performing determination processing for determining whether the captured image contains a predetermined object, performing image processing based on the result of the determination processing, and supplying second image data based on the image processing. The display device has a function of receiving the first and second image data. The first display element has a function of displaying an image based on the first image data, and the second display element has a function of displaying an image based on the second image data.

Abstract: To reduce the effect of external light and to improve the accuracy of detecting the location of a touch. In an image-capture period, light emission from a self-light-emitting element is controlled, and imaging data at the time of displaying white on a display screen and imaging data at the time of displaying black on the display screen are output from each sensor pixel. The location of a sensor pixel where a difference between the two pieces of imaging data output from the same sensor pixel is the greatest is detected. Thus, the location of a touch of the object on the display screen is detected with high accuracy. By utilizing a difference between imaging data at the time of reverse display, the effect of external light can be reduced.

Abstract: A semiconductor device suitable for low-voltage driving. The semiconductor device includes a first transistor, a second transistor, a power supply line, a circuit, and a memory circuit. The first transistor controls electrical continuity between the circuit and the power supply line. The memory circuit stores data for setting a gate potential of the first transistor. The second transistor controls electrical continuity between an output node of the memory circuit and a gate of the first transistor. The second transistor is a transistor with an ultralow off-state current, for example, an oxide semiconductor transistor. In a period for operating the circuit, a first potential is input to the power supply line and the second transistor is turned off. In a period for updating the gate potential of the first transistor, a second potential is input to the power supply line. The second potential is higher than the first potential.

Abstract: A novel semiconductor device, a semiconductor device where influence of noise is lessened, or a semiconductor device with high reliability is provided. A first circuit has a function of generating an optical data signal in accordance with the amount of irradiation light and a function of generating a reset signal corresponding to a reset state of the first circuit. A second circuit has a function of controlling output of the optical data signal and the reset signal from the first circuit to a fourth circuit. A third circuit has a function of controlling generation of the reset signal to be output from the first circuit to the fourth circuit. The fourth circuit has a function of calculating the difference between the optical data signal input from the first circuit and the reset signal input from the first circuit after input of the optical data signal.

Abstract: Influence of external light is suppressed. With a photodetector including a photodetector circuit which generates a data signal in accordance with illuminance of incident light and a light unit which overlaps with the photodetector circuit, a first data signal is generated by the photodetector circuit when the light unit is in an ON state, a second data signal is formed by the photodetector circuit when the light unit is in an OFF state, and the first data signal and the second data signal are compared, so that a difference data signal that is data of a difference between the two compared data signals is generated.

Abstract: A low-power voltage controlled oscillator is provided. The voltage controlled oscillator includes (2n+1) first circuit components (n is an integer of one or more). An output terminal of the first circuit component in a k-th stage (k is an integer of one or more and 2n or less) is connected to an input terminal of the first circuit component in a (k+1)-th stage. An output terminal of the first circuit component in a (2n+1)-th stage is connected to an input terminal of the first circuit component in a first stage. One of the first circuit components includes a second circuit component and a third circuit component whose input terminal is connected to an output terminal of the second circuit component. The third circuit component includes a first transistor and a second transistor whose source-drain resistance is controlled in accordance with a signal input to a gate through the first transistor.

Abstract: Provided is a semiconductor device in which leakage current due to miniaturization of a semiconductor element is reduced and delay at a time of context switch of a multi-context PLD is reduced. A first transistor and a second transistor included in a charge retention circuit functioning as a configuration memory each include an oxide semiconductor in a semiconductor layer serving as a channel formation region. One of a source and a drain of the first transistor is electrically connected to a gate of the second transistor. One of a source and a drain of the second transistor is connected to a switch for context switch. In the switch used for context switch, electrostatic capacitance on an input side to which the one of the source and the drain of the second transistor is connected is larger than electrostatic capacitance on an output side.

Abstract: Skew of a multi-context PLD in context switch is reduced to achieve low power consumption. The frequency of a clock signal is switched in context switch operation in accordance with circuit operation to secure time required for context switch. By returning the frequency of the clock signal to the original frequency after executing the context switch, the PLD can maintain high-speed processing and perform the context switch accurately and safely. The time required for the context switch mainly depends on a hardware structure (circuit layout including a parasitic component). Thus, the reliability in the context switch can be improved when time that is equal to or longer than the longest time required for circuit change is secured.

Abstract: To provide a semiconductor device having a novel configuration, in which a malfunction and power consumption are reduced. A data holding circuit which includes a flipflop including first and second latch circuits and a shadow register including a nonvolatile memory portion; and a control signal generation circuit which generates a first control signal supplied to the first latch circuit and a second control signal supplied to the second latch circuit are included. The shadow register is a circuit which controls data saving or data restoring between the first and second latch circuits on the basis of a saving control signal or a restore control signal. The control signal generation circuit is a circuit which generates the first and second control signals at L level in a period during which data is saved or restored, on the basis of a clock signal, the saving control signal, and the restore control signal.

Abstract: To provide a highly reliable and low-power-consumption semiconductor device functioning as a programmable logic device. A monitor circuit is provided to monitor a change in the potential of a configuration memory in which a transistor is turned off to hold charge and a potential corresponding to the charge is stored as configuration data. The reset of the configuration data is controlled in accordance with the potential change. With such a structure, the configuration memory can be reconfigured before the configuration data is lost, resulting in improved reliability of the semiconductor device. In addition, reconfiguration can be performed every time data is lost. Accordingly, power consumption can be reduced as compared with the structure where reconfiguration is performed periodically.

Abstract: A semiconductor device with a novel structure that can consume less power and have a reduced size of a circuit. In the semiconductor device, when configuration operation is started in a path transistor in a configuration memory, supply of an H-level potential to a signal pass node is stopped and then the potential of the signal pass node is set at L level, whereby configuration data is input to a memory potential retaining node, which is a gate of the path transistor. After the configuration operation is completed, the supply of the H-level potential to the signal pass node is resumed so that capacitive coupling occurs between the path transistor and the memory potential retaining node and increase the gate potential of the path transistor, so that a boosting effect is obtained. The above structure eliminates the need for a keeper circuit, reducing the power consumption and the circuit area.

Abstract: A semiconductor device includes a configuration memory that has functions of holding configuration data and generating a signal based on the configuration data, a context generator that has a function of generating a signal for controlling context switch, a clock generator that has a function of operating in a first mode or a second mode in accordance with the signal generated in the configuration memory, and a PLD. A clock signal is input to the context generator and the clock generator. The clock generator outputs the clock signal to the PLD in the first mode and stops outputting the clock signal to the PLD in the second mode.

Abstract: To achieve high processing capability, a semiconductor device includes first and second circuits, first to third wirings, and first to fourth transistors. The first circuit is electrically connected to the first wiring and a gate of the first transistor. One of a source and a drain of the first transistor is electrically connected to the second wiring. The other of the source and the drain of the first transistor is electrically connected to a gate of the second transistor. The second circuit is electrically connected to the first wiring and a gate of the third transistor. One of a source and a drain of the third transistor is electrically connected to the third wiring. The other of the source and the drain of the third transistor is electrically connected to a gate of the fourth transistor. One of a source and a drain of the fourth transistor is electrically connected to one of a source and a drain of the second transistor.

Abstract: Adverse effects of noise are reduced. A photodetector circuit, a difference data generation circuit, and a data input selection circuit are included. The photodetector circuit has a function of generating an optical data signal. A first data signal and a second data signal is input to the difference data generation circuit and the difference data generation circuit has a function of generating difference data of data of the first data signal and data of the second data signal. The data input selection circuit has a function of determining that the data of optical data signal is regarded as data of the first data signal or data of the second data signal.