Abstract: Provided is a memory device with reduced overhead power. A memory device includes a first circuit retaining data in a first period during which a power supply voltage is supplied; a second circuit saving the data retained in the first circuit in the first period and retaining the data saved from the first circuit in a second period during which the power supply voltage is not supplied; and a third circuit saving the data retained in the second circuit in the second period and retaining the data saved from the second circuit in a third period during which the power supply voltage is not supplied. The third circuit includes a transistor in which a channel formation region is provided in an oxide semiconductor film and a capacitor to which a potential corresponding to the data is supplied through the transistor.

Abstract: A semiconductor memory device or a semiconductor device which has high reading accuracy is provided. A bit line, a word line, a memory cell placed in an intersection portion of the bit line and the word line, and a reading circuit electrically connected to the bit line are provided. The memory cell includes a first transistor and an antifuse. The reading circuit includes a pre-charge circuit, a clocked inverter, and a switch. The pre-charge circuit includes a second transistor and a NAND circuit. The semiconductor memory device includes transistor in each of which an oxide semiconductor is used in a channel formation region, as the first transistor and the second transistor.

Abstract: A display device in which light leakage in a monitor element portion is prevented without increasing the number of steps and cost is provided. The display device includes a monitor element for suppressing influence on a light-emitting element due to temperature change and change over time and a TFT for driving the monitor element, in which the TFT for driving the monitor element is provided so as not to overlap the monitor element. Furthermore, the display device includes a first light shielding film and a second light shielding film, in which the first light shielding film is provided so as to overlap a first electrode of the monitor element and the second light shielding film is electrically connect to the first light shielding film through a contact hole formed in an interlayer insulating film. The contact hole is formed so as to surround the outer edge of the first electrode of the monitor element.

Abstract: An object is to provide a semiconductor memory device that enables low power consumption of a memory cell of a CAM including a nonvolatile memory device. Another object is to provide a semiconductor memory device without degradation due to repeated data writing. Still another object is to provide a nonvolatile memory device that enables high density of memory cells. A semiconductor memory device is provided which includes a memory circuit including a first transistor including an oxide semiconductor in a semiconductor layer, and a capacitor in which a potential corresponding to written data can be retained by turning off the first transistor; and a reference circuit for referring the written potential. The semiconductor memory device enables a high-speed search function by obtaining the address of data generated by detecting the conducting state of a second transistor in the reference circuit.

Abstract: A method for driving an electronic device stably is provided. The electronic device includes a power supply circuit to which power is fed by power sequentially supplied from a contactless power feeding device, and a plurality of loads to which power is sequentially supplied from the power supply circuit. Further, a method for driving an electronic device stably is provided. The electronic device includes a power supply circuit to which power is fed by power supplied from a contactless power feeding device, and one or more loads to which the power supply circuit repeatedly supplies power. The power supply potential Vdd is restored to more than or equal to 90% of the initial potential Vdd0 within an interval in which the power supply circuit is not connected to a load; then, the next load may be connected to the power supply circuit, and may be driven.

Abstract: A display device in which light leakage in a monitor element portion is prevented without increasing the number of steps and cost is provided. The display device includes a monitor element for suppressing influence on a light-emitting element due to temperature change and change over time and a TFT for driving the monitor element, in which the TFT for driving the monitor element is provided so as not to overlap the monitor element. Furthermore, the display device includes a first light shielding film and a second light shielding film, in which the first light shielding film is provided so as to overlap a first electrode of the monitor element and the second light shielding film is electrically connect to the first light shielding film through a contact hole formed in an interlayer insulating film. The contact hole is formed so as to surround the outer edge of the first electrode of the monitor element.

Abstract: A signal processing circuit that consumes less power by stop of supply of power for a short time. In a storage element, before supply of power is stopped, data in a first storage circuit is stored to a second storage circuit, and the data is read from the second storage circuit and a verification circuit can determine whether or not the data in the second storage circuit matches the data in the first storage circuit. After supply of power is restarted, the data in the second storage circuit is stored to the first storage circuit, and the verification circuit can determine whether or not the data in the second storage circuit matches the data in the first storage circuit. In such a manner, verification can be performed without requiring a time for verification.

Abstract: A display device in which light leakage in a monitor element portion is prevented without increasing the number of steps and cost is provided. The display device includes a monitor element for suppressing influence on a light-emitting element due to temperature change and change over time and a TFT for driving the monitor element, in which the TFT for driving the monitor element is provided so as not to overlap the monitor element. Furthermore, the display device includes a first light shielding film and a second light shielding film, in which the first light shielding film is provided so as to overlap a first electrode of the monitor element and the second light shielding film is electrically connect to the first light shielding film through a contact hole formed in an interlayer insulating film. The contact hole is formed so as to surround the outer edge of the first electrode of the monitor element.

Abstract: A semiconductor device in which a nonvolatile memory can normally operate and power saving can be performed with a P-state function, and a driving method of the semiconductor device are provided. The semiconductor device includes: a first circuit configured to control a state including a driving voltage and a clock frequency of a processor core; a first memory circuit and a second memory circuit which store state data; a second circuit generating a power supply voltage and a third circuit generating a clock which are electrically connected to the first circuit; and the processor core electrically connected to the second circuit and the third circuit through a switch. The processor cores includes: a volatile memory; and a nonvolatile memory transmitting and receiving data to/from the first memory.

Abstract: It is to provide a semiconductor memory device in which high voltage is not needed in writing, a defect is less likely to occur, the writing time is short, and data cannot be rewritten without an increase in cost. The semiconductor memory device includes a memory element which includes a diode-connected first transistor, a second transistor whose gate is connected to one terminal of a source electrode and a drain electrode of the diode-connected first transistor, and a capacitor connected to the one terminal of the source electrode and the drain electrode of the diode-connected first transistor and the gate of the second transistor.

Abstract: An in-vehicle system for communicating with an external tool for storing a tool secret key includes: a communication device; a tool key acquisition device; and a communication controller. The in-vehicle system and an external server for storing external tool information provide a vehicular communication system. The external tool information provides a tool public key and key identification information. The tool public key pairs with the tool secret key. When the external tool requests communication connection with the in-vehicle system, the tool key acquisition device transmits the key identification information to the external server, so that the tool key acquisition device acquires the tool public key from the external server. The communication controller performs cryptographic communication with the external tool using the tool public key.

Abstract: A display device in which light leakage in a monitor element portion is prevented without increasing the number of steps and cost is provided. The display device includes a monitor element for suppressing influence on a light-emitting element due to temperature change and change over time and a TFT for driving the monitor element, in which the TFT for driving the monitor element is provided so as not to overlap the monitor element. Furthermore, the display device includes a first light shielding film and a second light shielding film, in which the first light shielding film is provided so as to overlap a first electrode of the monitor element and the second light shielding film is electrically connect to the first light shielding film through a contact hole formed in an interlayer insulating film. The contact hole is formed so as to surround the outer edge of the first electrode of the monitor element.

Abstract: A signal processing unit with reduced power consumption is provided. A transistor in which a channel is formed in an oxide semiconductor is used for a storage circuit included in the signal processing unit, so that data can be held (stored) even while supply of power is stopped. Non-destructive reading can be performed on the data stored in the storage circuit even when supply of power to the signal processing unit is stopped.

Abstract: A bus monitoring security device is connected to a bus, which includes a tool side bus having a tool connection terminal and an ECU side bus. The ECU side bus is coupled with an ECU, and the tool side bus is coupled with a tool capable of communicating with the ECU via the tool connection terminal. The tool side bus and the ECU side bus are separately coupled with the bus monitoring security device. The bus monitoring security device includes: a controller for determining whether the tool being to access the ECU is connected to the ECU side bus, and for restricting transmission and reception of data between the tool and the ECU when the controller determines that the tool is connected to the ECU side bus.

Abstract: An in-vehicle system comprising a gateway between multiple networks is disclosed. One of the networks specifies that when a source apparatus connected to the one of the networks sends a request message to a destination apparatus connected to another one of the networks, the source apparatus should time-out if the source apparatus does not receive a response message within a specified time after sending the request message. Upon receipt of the request message, the gateway relays the request message to the destination apparatus and sends a wait request code to the source apparatus to instruct the source apparatus to wait by extending the specified time.

Abstract: It is an object to provide a highly reliable semiconductor device which operates normally even when a communication distance is extremely short. A semiconductor device which transmits/receives data by wireless communication includes a comparison circuit which compares electric power supplied form outside with electric power serving as a reference; a bias circuit portion which outputs a protection signal and a modulation signal in accordance with output of the comparison circuit; and a protection/modulation circuit which performs protection to prevent degradation and breakdown of elements of the semiconductor device and modulation to transmit data, with one circuit.

Abstract: A display device in which light leakage in a monitor element portion is prevented without increasing the number of steps and cost is provided. The display device includes a monitor element for suppressing influence on a light-emitting element due to temperature change and change over time and a TFT for driving the monitor element, in which the TFT for driving the monitor element is provided so as not to overlap the monitor element. Furthermore, the display device includes a first light shielding film and a second light shielding film, in which the first light shielding film is provided so as to overlap a first electrode of the monitor element and the second light shielding film is electrically connect to the first light shielding film through a contact hole formed in an interlayer insulating film. The contact hole is formed so as to surround the outer edge of the first electrode of the monitor element.

Abstract: An object is to provide a semiconductor memory device that enables low power consumption of a memory cell of a CAM including a nonvolatile memory device. Another object is to provide a semiconductor memory device without degradation due to repeated data writing. Still another object is to provide a nonvolatile memory device that enables high density of memory cells. A semiconductor memory device is provided which includes a memory circuit including a first transistor including an oxide semiconductor in a semiconductor layer, and a capacitor in which a potential corresponding to written data can be retained by turning off the first transistor; and a reference circuit for referring the written potential. The semiconductor memory device enables a high-speed search function by obtaining the address of data generated by detecting the conducting state of a second transistor in the reference circuit.

Abstract: A signal processing unit with reduced power consumption is provided. A transistor in which a channel is formed in an oxide semiconductor is used for a storage circuit included in the signal processing unit, so that data can be held (stored) even while supply of power is stopped. Non-destructive reading can be performed on the data stored in the storage circuit even when supply of power to the signal processing unit is stopped.

Abstract: A vehicular system includes a master ECU, a first slave ECU, and a second slave ECU. The second slave ECU transmits a storing request to the master ECU on detection of a malfunction. The master ECU transmits a storing instruction for causing diagnostic information to be stored, on reception of the storing request. The first slave ECU generates diagnostic information on the first slave ECU, on reception of the storing instruction from the master ECU. The first slave ECU further stores the generated diagnostic information in a retention storage medium. The retention storage medium is configured to retain validity determination information in a condition where the first slave ECU is not supplied with electric power source.