Abstract:
An object is to provide a semiconductor device that automatically adjusts the luminance of a display device. The semiconductor device includes an illuminometer, a threshold detector, a timing controller, a digital-to-analog converter circuit, a first display panel, and a second display panel. The illuminance of external light is measured with the illuminometer, and the threshold value of digital video data is determined by the threshold detector in accordance with the illuminance. The timing controller generates a signal for the first display panel or a signal for the second display panel on the basis of the threshold value and video data transmitted from the outside. The signal for the first display panel and the signal for the second display panel are input to one digital-to-analog converter circuit and converted into digital signals, and the obtained digital signals are input to a corresponding one of the first display panel and the second display panel.
Abstract:
A semiconductor device that suppresses operation delay due to stop and restart of the supply of a power supply potential is provided. A potential corresponding to data held while power supply potential is continuously supplied is backed up in a node connected to a capacitor while the supply of the power supply potential is stopped. Then, by utilizing change in resistance of a channel in a transistor whose gate is the node, the data is restored with restart of the supply of the power supply potential. Note that by supplying a high potential to the node before the data back up, high-speed and accurate data back up is possible.
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:
In a CMOS image sensor in which a plurality of pixels is arranged in a matrix, a transistor in which a channel formation region includes an oxide semiconductor is used for each of a charge accumulation control transistor and a reset transistor which are in a pixel portion. After a reset operation of the signal charge accumulation portion is performed in all the pixels arranged in the matrix, a charge accumulation operation by the photodiode is performed in all the pixels, and a read operation of a signal from the pixel is performed per row. Accordingly, an image can be taken without a distortion.
Abstract:
A nonvolatile semiconductor device which can be driven at low voltage is provided. A nonvolatile semiconductor device with low power consumption is provided. A Schmitt trigger NAND circuit and a Schmitt trigger inverter are included. Data is held in a period when the supply of power supply voltage is continued, and a potential corresponding to the data is stored at a node electrically connected to a capacitor before a period when the supply of power supply voltage is stopped. By utilizing a change in channel resistance of a transistor whose gate is connected to the node, the data is restored in response to the restart of the supply of power supply voltage.
Abstract:
Data of a register in a programmable logic element is retained. A volatile storage circuit and a nonvolatile storage circuit are provided in a register of a programmable logic element whose function can be changed in response to a plurality of context signals. The nonvolatile storage circuit includes nonvolatile storage portions for storing data in the register. The number of nonvolatile storage portions corresponds to the number of context signals. With such a structure, the function can be changed each time context signals are switched and data in the register that is changed when the function is changed can be backed up to the nonvolatile storage portion in each function. In addition, the function can be changed each time context signals are switched and the data in the register that is backed up when the function is changed can be recovered to the volatile storage circuit.
Abstract:
To provide a semiconductor device in which power consumption can be reduced and operation delay due to a stop and a restart of supply of power supply voltage can be suppressed and a driving method thereof. A potential corresponding to data held in a period during which power supply voltage is continuously supplied is saved to a node connected to a capacitor before the supply of power supply voltage is stopped. By utilizing change of channel resistance of a transistor whose gate is the node, data is loaded when the supply of power supply voltage is restarted.
Abstract:
To provide a semiconductor memory device which can be manufactured with high yield and which can achieve higher integration. A pair of memory cells adjacent to each other in the bit line direction is connected to a bit line through a common contact hole. The pair of memory cells adjacent to each other in the bit line direction shares an electrode connected to the bit line. An oxide semiconductor layer included in the memory cell is provided to overlap with a word line and a capacitor line. A transistor and a capacitor included in the memory cell are each provided to overlap with the bit line connected to the memory cell.
Abstract:
To provide a PLD having a reduced circuit area and an increased operation speed. In the circuit structure, a gate of a transistor provided between an input terminal and an output terminal of a programmable switch element is in an electrically floating state in a period when a signal is input to the programmable switch element. The structure enables the voltage of a gate to be increased by a boosting effect in response to a signal supplied from programmable logic elements, suppressing a reduction in amplitude voltage. This can reduce a circuit area by a region occupied by a booster circuit such as a pull-up circuit and increase operation speed.
Abstract:
A programmable logic device includes a plurality of programmable logic elements (PLE) whose electrical connection is controlled by first configuration data. Each of The PLEs includes an LUT in which a relationship between a logic level of an input signal and a logic level of an output signal is determined by second configuration data, an FF to which the output signal of the LUT is input, and an MUX. The MUX includes at least two switches each including first and second transistor. A signal including third configuration data is input to a gate of the second transistor through the first transistor. The output signal of the LUT or an output signal of the FF is input to one of a source and a drain of the second transistor.