Patents by Inventor Yoshifumi Ikenaga
Yoshifumi Ikenaga has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20170228338Abstract: A semiconductor device (1) according to the present invention includes a plurality of buses (B1 to Bm), a control unit (10) connected to the plurality of buses (B1 to Bm), the control unit (10) being configured to acquire information about a communication specification including information about a drive voltage from each of a plurality of externally-disposed modules (M1 to Mn) through one of the plurality of buses (B1 to Bm), and a switch circuit (13) configured to set a connection between the plurality of modules (M1 to Mn) and the plurality of buses (B1 to Bm) based on the information about the communication specification for each of the plurality of modules (M1 to Mn) acquired by the control unit (10).Type: ApplicationFiled: November 14, 2014Publication date: August 10, 2017Inventor: Yoshifumi IKENAGA
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Publication number: 20160342552Abstract: The invention aims at providing a semiconductor device, a semiconductor system including same, and a semiconductor device control method enabling it to correctly judge that a module has been coupled to and decoupled from a communication bus. According to one embodiment, a host controller includes a variable resistance element and a control circuit that varies the resistance value of the variable resistance element so that the potential of a potential detecting line which is determined by the variable resistance element and a resistance element provided in each of modules will fall within a predefined range. It is thus possible to keep that potential varying to a certain extent or more due to coupling and decoupling of a module to/from the communication bus. It is therefore possible to correctly judge that a module has been coupled/decoupled to/from the communication bus.Type: ApplicationFiled: April 9, 2016Publication date: November 24, 2016Inventor: Yoshifumi IKENAGA
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Publication number: 20160191044Abstract: According to an embodiment, a module M1 includes an internal circuit 14, and a standard information transmitting unit 15 that transmits a result of a comparison between a voltage supplied from an externally-disposed control device 1 and a threshold voltage specified based on a communication standard of the internal circuit 14 to the control device 1 as information on the communication standard of the internal circuit 14. As a result, the module M1 can communicate with the control device 1 according to a correct communication standard.Type: ApplicationFiled: October 28, 2015Publication date: June 30, 2016Applicant: RENESAS ELECTRONICS CORPORATIONInventor: Yoshifumi IKENAGA
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Publication number: 20160065059Abstract: According to an embodiment of the present invention, a semiconductor device includes a charge pump circuit having a plurality of booster units which are connected in series between an input terminal and an output terminal, each of the plurality of booster units includes: a main transistor that is diode-connected so as to cause a forward current to flow in a direction from an internal input terminal toward an internal output terminal; a sub-transistor that is connected between a first terminal of the main transistor and a back-gate terminal of the main transistor and has a control terminal connected to a second terminal of the main transistor; a resistor that connects the second terminal of the main transistor and the back-gate terminal of the main transistor; and a capacitor that is connected between the internal output terminal and a clock wire.Type: ApplicationFiled: July 18, 2015Publication date: March 3, 2016Inventor: Yoshifumi IKENAGA
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Publication number: 20160065070Abstract: According to one embodiment, a semiconductor device includes: a first switch SWx which switches whether or not to supply a first power supply voltage Vx generated by accumulating a charge outputted from a power source 10, as a second power supply voltage VDD to a first circuit 13, and a second switch SW1 which switches whether or not to connect to the first circuit 13 a smoothing capacitor C1 which suppresses a fluctuation of the second power supply voltage VDD, and the first switch SWx is switched to an on state in response to that the first power supply voltage Vx has reached a sufficient voltage, and then the second switch SW1 is switched to the on state in response to that the second power supply voltage VDD has reached a sufficient voltage.Type: ApplicationFiled: August 11, 2015Publication date: March 3, 2016Applicant: RENESAS ELECTRONICS CORPORATIONInventors: Koichiro NOGUCHI, Koichi NOSE, Yoshifumi IKENAGA, Yoichi YOSHIDA
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Publication number: 20150311706Abstract: A power supply device according to an embodiment comprises a plurality of power sources 10 each including an antenna and an AC/DC conversion unit, a plurality of consolidating units 13—1 to 13—i, and a power supply unit 15. The consolidating units 13—1 to 13—i respectively include consolidating circuits 14—1 to 14—i that selectively consolidate a plurality of DC signals 21—1 to 21—n supplied by the plurality of power sources 10. The power supply unit 15 includes a consolidating circuit 16 that selectively consolidates the DC signals 21—1 to 21—i output from the plurality of consolidating units 13—1 to 13—i, and a voltage conversion circuit 17 that converts a DC signal 23 resulting from consolidation in the consolidating circuit 16, to a predetermined voltage.Type: ApplicationFiled: April 18, 2015Publication date: October 29, 2015Inventors: Koichiro NOGUCHI, Koichi NOSE, Yoshifumi IKENAGA, Yoichi YOSHIDA
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Publication number: 20150311707Abstract: A power supply circuit according to an embodiment has a plurality of voltage sources, a switch circuit that switches between a state in which the plurality of voltage sources are connected in series and a state in which the plurality of voltage sources are connected in parallel, and a voltage control circuit that boosts an input voltage. The switch circuit connects the plurality of voltage sources in series, supplies an output of the plurality of serially connected voltage sources to an output node of the voltage control circuit, thereafter connects the plurality of voltage sources in parallel, and supplies outputs of the plurality of parallel-connected voltage sources to the voltage control circuit. The voltage control circuit boosts voltages of the plurality of parallel-connected voltage sources.Type: ApplicationFiled: April 13, 2015Publication date: October 29, 2015Inventor: Yoshifumi IKENAGA
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Publication number: 20150180239Abstract: There is a problem in the prior semiconductor devices that energy recovery efficiency is low. According to one embodiment of the present invention, a power supply circuit includes an alternating-current signal synthesis unit including a plurality of alternating-current coupling elements having primary sides to which respective input alternating-current signals are input and secondary sides connected in series with each other, and a control circuit that outputs an input selection signal specifying a combination of the input alternating-current signals to be synthesized. The control circuit generates the input selection signal so as to maximize the output alternating-current signal synthesized by the alternating-current synthesis signal unit.Type: ApplicationFiled: October 25, 2014Publication date: June 25, 2015Inventors: Koichiro NOGUCHI, Koichi Nose, Yoshifumi Ikenaga, Yoichi Yoshida
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Publication number: 20150091382Abstract: A power supply circuit according to an embodiment of the invention includes: voltage sources; voltage control circuits that boost an input voltage; and a voltage source connection switch that connects at least one of the voltage sources to one of the voltage control circuits. For example, the voltage source connection switch connects, to the voltage control circuit, a voltage source having a voltage lower than a predetermined reference voltage among the voltage sources, and connects, to the voltage control circuit, a voltage source having a voltage equal to or higher than the determined reference voltage among the voltage sources.Type: ApplicationFiled: September 7, 2014Publication date: April 2, 2015Inventor: Yoshifumi IKENAGA
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Patent number: 8390313Abstract: When an operation of a specified one of monitor circuits is defective or any of elements forming a ring oscillator in each of the monitor circuits has characteristic abnormality, if voltage control is performed based on a result from the monitor operating at a lowest speed, a required voltage may be overestimated. This results in an increase in power consumption, and also causes an accuracy reduction when the average value of detection results from the multiple monitors is calculated. The multiple monitor circuits are provided. Of the detection results therefrom, any detection result falling outside a predetermined range is ignored, and the average value of the remaining monitor results is used as a final monitor detection value.Type: GrantFiled: March 21, 2011Date of Patent: March 5, 2013Assignee: Renesas Electronics CorporationInventors: Yoshifumi Ikenaga, Masahiro Nomura
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Patent number: 8368457Abstract: The present invention is a semiconductor integrated circuit device including a target circuit, a voltage supply circuit that supplies the power supply voltage to the target circuit, a control circuit that controls an output voltage of the voltage supply circuit, and a target voltage prediction circuit that predicts a voltage value of the power supply voltage. The control circuit changes the output voltage of the voltage supply circuit by a predetermined voltage value. The target voltage prediction circuit detects a change amount of an operating frequency of the target circuit along with the change of the predetermined voltage value, and calculates a target voltage value based on a relation between the change amount of the operating frequency and the predetermined voltage value. The voltage supply circuit supplies a power supply voltage corresponding to the target voltage value to the target circuit.Type: GrantFiled: September 15, 2010Date of Patent: February 5, 2013Assignee: Renesas Electronics CorporationInventor: Yoshifumi Ikenaga
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Publication number: 20110241725Abstract: When an operation of a specified one of monitor circuits is defective or any of elements forming a ring oscillator in each of the monitor circuits has characteristic abnormality, if voltage control is performed based on a result from the monitor operating at a lowest speed, a required voltage may be overestimated. This results in an increase in power consumption, and also causes an accuracy reduction when the average value of detection results from the multiple monitors is calculated. The multiple monitor circuits are provided. Of the detection results therefrom, any detection result falling outside a predetermined range is ignored, and the average value of the remaining monitor results is used as a final monitor detection value.Type: ApplicationFiled: March 21, 2011Publication date: October 6, 2011Inventors: Yoshifumi IKENAGA, Masahiro Nomura
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Patent number: 8008659Abstract: A substrate bias is controlled such that a leakage current is minimum. A semiconductor integrated circuit device comprises a leakage detecting circuit which detects a leakage current by using leakage detecting MOSFETs, a control circuit which generates a control signal depending on an output from the leakage detecting circuit, a substrate bias generating circuit which changes a substrate bias depending on the control signal, and a controlled circuit including a MOSFET having the same characteristics as that of each of the leakage detecting MOSFETs. The leakage detecting circuit detects a substrate leakage current which includes as the substrate bias becomes deep and a subthreshold leakage current which decreases as the substrate bias becomes deep.Type: GrantFiled: October 31, 2005Date of Patent: August 30, 2011Assignee: NEC CorporationInventors: Yoshifumi Ikenaga, Koichi Takeda, Masahiro Nomura
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Patent number: 8004351Abstract: A semiconductor integrated circuit device includes: a target circuit whose at least power supply voltage is variable; a power supply voltage providing circuit feeding the target circuit with a power supply voltage; and a minimum energy point monitor circuit detecting an energy-minimizing power supply voltage which minimizes a change in the energy consumed by the target circuit upon a change in the power supply voltage. The power supply voltage delivered by the power supply voltage providing circuit is controlled so as to be equal to the energy-minimizing power supply voltage detected by the minimum energy point monitor circuit.Type: GrantFiled: December 28, 2007Date of Patent: August 23, 2011Assignee: NEC CorporationInventors: Yoshifumi Ikenaga, Masahiro Nomura
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Patent number: 8004348Abstract: A control circuit controls a power-source-voltage feed circuit, and controls a power source voltage fed to a target circuit. A reference-speed monitor monitors whether or not a delay time of a critical path in the target circuit is satisfies a required operational speed. A voltage-difference monitor monitors a difference between the power source voltage of the target circuit and a threshold voltage of the target circuit, to output the voltage difference information. The control circuit determines whether to increase or decrease the power source voltage based on a result of monitoring by the reference-speed monitor. The control circuit determines the change rate of the power source voltage so that the control rate of the power source voltage is proportional to the voltage difference information output from the voltage-difference monitor.Type: GrantFiled: February 14, 2008Date of Patent: August 23, 2011Assignee: NEC CorporationInventors: Yoshifumi Ikenaga, Masahiro Nomura
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Publication number: 20110187419Abstract: A semiconductor integrated circuit is capable of accurately detecting the characteristics of a chip. The semiconductor integrated circuit includes a monitor circuit and a control circuit. The control circuit generates a clock pulse signal having M successive pulses (M is 2 or a greater integer), and outputs the clock pulse signal to the monitor circuit. The monitor circuit includes a frequency divider and a ring oscillator. The frequency divider frequency divides the clock pulse signal by M and generates the resulting signal as an enable signal. The ring oscillator generates an oscillation signal as a monitor output value during a period defined in accordance with the enable signal.Type: ApplicationFiled: January 31, 2011Publication date: August 4, 2011Inventors: Yoshifumi Ikenaga, Masahiro Nomura
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Publication number: 20110068855Abstract: The present invention is a semiconductor integrated circuit device including a target circuit, a voltage supply circuit that supplies the power supply voltage to the target circuit, a control circuit that controls an output voltage of the voltage supply circuit, and a target voltage prediction circuit that predicts a voltage value of the power supply voltage. The control circuit changes the output voltage of the voltage supply circuit by a predetermined voltage value. The target voltage prediction circuit detects a change amount of an operating frequency of the target circuit along with the change of the predetermined voltage value, and calculates a target voltage value based on a relation between the change amount of the operating frequency and the predetermined voltage value. The voltage supply circuit supplies a power supply voltage corresponding to the target voltage value to the target circuit.Type: ApplicationFiled: September 15, 2010Publication date: March 24, 2011Applicant: Renesas Electronics CorporationInventor: Yoshifumi Ikenaga
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Publication number: 20100327961Abstract: A semiconductor integrated circuit device includes: a target circuit whose at least power supply voltage is variable; a power supply voltage providing circuit feeding the target circuit with a power supply voltage; and a minimum energy point monitor circuit detecting an energy-minimizing power supply voltage which minimizes a change in the energy consumed by the target circuit upon a change in the power supply voltage. The power supply voltage delivered by the power supply voltage providing circuit is controlled so as to be equal to the energy-minimizing power supply voltage detected by the minimum energy point monitor circuit.Type: ApplicationFiled: December 28, 2007Publication date: December 30, 2010Inventors: Yoshifumi Ikenaga, Masahiro Nomura
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Publication number: 20100295530Abstract: A power supply voltage control circuit controls power supply voltage supplied to a target circuit that performs certain signal processing. The power supply voltage control circuit includes a control signal generation circuit that selectively generates first and second control signals when the power supply voltage supplied to the target circuit is increased from a first power supply voltage to a second power supply voltage, the second power supply voltage being higher than the first power supply voltage, and a power supply circuit that increases the power supply voltage toward a voltage level of the second power supply voltage based on the first control signal, or increases the power supply voltage to a voltage level higher than the second power supply voltage first and subsequently decreases the power supply voltage to the second power supply voltage based on the second control signal.Type: ApplicationFiled: April 29, 2010Publication date: November 25, 2010Applicant: NEC Electronics CorporationInventors: Yoshifumi Ikenaga, Masahiro Nomura
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Publication number: 20100033235Abstract: A control circuit controls a power-source-voltage feed circuit, and controls a power source voltage fed to a target circuit. A reference-speed monitor monitors whether or not a delay time of a critical path in the target circuit is satisfies a required operational speed. A voltage-difference monitor monitors a difference between the power source voltage of the target circuit and a threshold voltage of the target circuit, to output the voltage difference information. The control circuit determines whether to increase or decrease the power source voltage based on a result of monitoring by the reference-speed monitor. The control circuit determines the change rate of the power source voltage so that the control rate of the power source voltage is proportional to the voltage difference information output from the voltage-difference monitor.Type: ApplicationFiled: February 14, 2008Publication date: February 11, 2010Inventors: Yoshifumi Ikenaga, Masahiro Nomura