Patents by Inventor Masanao Yamaoka

Masanao Yamaoka 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).

  • Publication number: 20110188329
    Abstract: The semiconductor integrated circuit (1) has a memory (4) and a logic circuit (5), which are mixedly palletized on a silicon substrate (2). The memory includes a partially-depleted type nMOS (6) having an SOI structure and formed on UTB (3). The partially-depleted type nMOS has a backgate region (14) under UTB, to which a voltage can be applied independently of a corresponding gate terminal. The logic circuit includes an nMOS (7) and a pMOS (8), and both are of a fully-depleted type, formed on UTB and have an SOI structure.
    Type: Application
    Filed: April 13, 2011
    Publication date: August 4, 2011
    Inventors: Takayuki Kawahara, Masanao Yamaoka, Nobuyuki Sugii
  • Publication number: 20110181319
    Abstract: The present invention provides a high speed and low power consumption LSI operable in a wide temperature range in which a MOS transistor having back gates is used specifically according to operating characteristics of a circuit. In the LSI, an FD-SOI structure having an embedded oxide film layer is used and a lower semiconductor region of the embedded oxide film layer is used as a back gate. A voltage for back gates in the logic circuits having a small load in the logic circuit block is controlled in response to activation of the block from outside of the block. Transistors, in which the gate and the back gate are connected to each other, are used for the circuit generating the back gate driving signal, and logic circuits having a heavy load such as circuit block output section, and the back gates are directly controlled according to the gate input signal.
    Type: Application
    Filed: April 6, 2011
    Publication date: July 28, 2011
    Inventors: Takayuki KAWAHARA, Masanao YAMAOKA
  • Patent number: 7961545
    Abstract: A logic circuit in a system LSI is provided with a power switch so as to cut off the switch at the time of standby, reducing leakage current. At the same time, an SRAM circuit of the system LSI controls a substrate bias to reduce leakage current.
    Type: Grant
    Filed: December 3, 2009
    Date of Patent: June 14, 2011
    Assignee: Renesas Electronics Corporation
    Inventors: Masanao Yamaoka, Koichiro Ishibashi, Shigezumi Matsui, Kenichi Osada
  • Publication number: 20110133786
    Abstract: A speed performance measurement circuit that may perform speed performance measurement is provided between a first logic circuit and a second logic circuit. The speed performance measurement circuit includes a first flip flop that stores first data, a first delay circuit that delays the first data and generates second data, and a second flip flop that stores the second data. Furthermore, the speed performance measurement circuit includes a first comparator circuit that compares output of the first flip flop to output of the second flip flop, and a third flip flop that stores output data from the first comparator circuit in accordance with timing of the first clock signal. Data in a normal path is compared to data in a path delayed by a certain time to measure speed, and power voltage of a circuit is determined based on such comparison. Thus, change in speed with respect to power voltage in a critical path can be measured.
    Type: Application
    Filed: February 15, 2011
    Publication date: June 9, 2011
    Inventors: Masanao YAMAOKA, Kenichi OSADA
  • Publication number: 20110122681
    Abstract: An object of the present invention is to provide a technique of reducing the power consumption of an entire low power consumption SRAM LSI circuit employing scaled-down transistors and of increasing the stability of read and write operations on the memory cells by reducing the subthreshold leakage current and the leakage current flowing from the drain electrode to the substrate electrode. Another object of the present invention is to provide a technique of preventing an increase in the number of transistors in a memory cell and thereby preventing an increase in the cell area. Still another object of the present invention is to provide a technique of ensuring stable operation of an SRAM memory cell made up of SOI or FD-SOI transistors having a BOX layer by controlling the potentials of the wells under the BOX layers of the drive transistors.
    Type: Application
    Filed: February 4, 2011
    Publication date: May 26, 2011
    Inventors: Masanao YAMAOKA, Takayuki Kawahara
  • Publication number: 20110115474
    Abstract: To provide an LSI having a low power mode that can prevent an apparatus on which the LSI is mounted from resulting in performance degradation, etc. even when its electric power is not reduced in the low power mode. Devised is a circuit that instructs an operation mode and detects whether the LSI operates as specified by the mode, and that measures a current at the time of the low power mode in a pseudo manner and, if despite having shifted to the low power mode, the current is not reduced actually, issues an alarm signal.
    Type: Application
    Filed: November 2, 2010
    Publication date: May 19, 2011
    Inventors: Masanao Yamaoka, Kenichi Osada, Minoru Motoyoshi, Tetsuya Fukuoka
  • Patent number: 7943996
    Abstract: The present invention provides a high speed and low power consumption LSI operable in a wide temperature range in which a MOS transistor having back gates is used specifically according to operating characteristics of a circuit. In the LSI, an FD-SOI structure having an embedded oxide film layer is used and a lower semiconductor region of the embedded oxide film layer is used as a back gate. A voltage for back gates in the logic circuits having a small load in the logic circuit block is controlled in response to activation of the block from outside of the block. Transistors, in which the gate and the back gate are connected to each other, are used for the circuit generating the back gate driving signal, and logic circuits having a heavy load such as circuit block output section, and the back gates are directly controlled according to the gate input signal.
    Type: Grant
    Filed: September 2, 2010
    Date of Patent: May 17, 2011
    Assignee: Renesas Electronics Corporation
    Inventors: Takayuki Kawahara, Masanao Yamaoka
  • Publication number: 20110102019
    Abstract: Thresholds of MISFETS of a Full Depletion-type SOI substrate cannot be controlled by changing impurity density as with bulk silicon MISFETs. Therefore, it is difficult to set a suitable threshold for each circuit. According to the semiconductor device of the present invention, gate electrodes of P-channel type MISFETs composing a memory cell are made of N-type polysilicon, gate electrodes of N-channel type MISFETs are made of P-type polysilicon and gate electrodes of P-channel type and N-channel type MISFETs of peripheral circuits and a logic circuit are made of P-type silicon germanium. A suitable threshold can be achieved for each circuit using a SOI substrate, thereby making it possible to fully leverage the characteristics of the SOI substrate.
    Type: Application
    Filed: January 10, 2011
    Publication date: May 5, 2011
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Kenichi OSADA, Takayuki KAWAHARA, Masanao YAMAOKA
  • Patent number: 7920438
    Abstract: An SRAM circuit operates at a reduced operation margin, especially at a low operating voltage by increasing or optimizing the operation margin of the SRAM circuit. The threshold voltage of the produced transistor in the SRAM circuit is detected to compare the operating voltage of a memory cell with the operating voltage of a peripheral circuit in order to adjust it to the optimum value, and the substrate bias voltage is further controlled.
    Type: Grant
    Filed: January 4, 2008
    Date of Patent: April 5, 2011
    Assignee: Renesas Electronics Corporation
    Inventors: Masanao Yamaoka, Kenichi Osada
  • Patent number: 7911221
    Abstract: A speed performance measurement circuit that may perform speed performance measurement is provided between a first logic circuit and a second logic circuit. The speed performance measurement circuit includes a first flip flop that stores first data, a first delay circuit that delays the first data and generates second data, and a second flip flop that stores the second data. Furthermore, the speed performance measurement circuit includes a first comparator circuit that compares output of the first flip flop to output of the second flip flop, and a third flip flop that stores output data from the first comparator circuit in accordance with timing of the first clock signal. Data in a normal path is compared to data in a path delayed by a certain time to measure speed, and power voltage of a circuit is determined based on such comparison. Thus, change in speed with respect to power voltage in a critical path can be measured.
    Type: Grant
    Filed: December 15, 2008
    Date of Patent: March 22, 2011
    Assignee: Renesas Electronics Corporation
    Inventors: Masanao Yamaoka, Kenichi Osada
  • Publication number: 20110063895
    Abstract: A semiconductor integrated circuit which can respond to changes of the amount of retained data at the time of standby is provided. The semiconductor integrated circuit comprises a logic circuit (logic) and plural SRAM modules. The plural SRAM modules perform power control independently of the logic circuit, and an independent power control is performed among the plural SRAM modules. Specifically, one terminal and the other terminal of a potential control circuit of each SRAM module are coupled to a cell array and a local power line, respectively. The local power line of one SRAM module and the local power line of the other SRAM module share a shared local power line. A power switch of one SRAM module and a power switch of the other SRAM module are coupled in common to the shared local power line.
    Type: Application
    Filed: August 12, 2010
    Publication date: March 17, 2011
    Inventors: Shigenobu KOMATSU, Masanao Yamaoka, Noriaki Maeda, Masao Morimoto, Yasuhisa Shimazaki, Yasuyuki Okuma, Toshiaki Sano
  • Publication number: 20110012206
    Abstract: When threshold voltages of constituent transistors are reduced in order to operate an SRAM circuit at a low voltage, there is a problem in that a leakage current of the transistors is increased and, as a result, electric power consumption when the SRAM circuit is not operated while storing data is increased. Therefore, there is provided a technique for reducing the leakage current of MOS transistors in SRAM memory cells MC by controlling a potential of a source line ssl of the driver MOS transistors in the memory cells.
    Type: Application
    Filed: September 27, 2010
    Publication date: January 20, 2011
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Masanao Yamaoka, Kenichi Osada, Kazumasa Yanagisawa
  • Publication number: 20100327356
    Abstract: The present invention provides a high speed and low power consumption LSI operable in a wide temperature range in which a MOS transistor having back gates is used specifically according to operating characteristics of a circuit. In the LSI, an FD-SOI structure having an embedded oxide film layer is used and a lower semiconductor region of the embedded oxide film layer is used as a back gate. A voltage for back gates in the logic circuits. having a small load in the logic circuit block is controlled in response to activation of the block from outside of the block. Transistors, in which the gate and the back gate are connected to each other, are used for the circuit generating the back gate driving signal, and logic circuits having a heavy load such as circuit block output section, and the back gates are directly controlled according to the gate input signal.
    Type: Application
    Filed: September 2, 2010
    Publication date: December 30, 2010
    Inventors: Takayuki KAWAHARA, Masanao YAMAOKA
  • Patent number: 7821814
    Abstract: When threshold voltages of constituent transistors are reduced in order to operate an SRAM circuit at a low voltage, there is a problem in that a leakage current of the transistors is increased and, as a result, electric power consumption when the SRAM circuit is not operated while storing data is increased. Therefore, there is provided a technique for reducing the leakage current of MOS transistors in SRAM memory cells MC by controlling a potential of a source line ssl of the driver MOS transistors in the memory cells.
    Type: Grant
    Filed: August 15, 2008
    Date of Patent: October 26, 2010
    Assignee: Renensas Electronics Corporation
    Inventors: Masanao Yamaoka, Kenichi Osada, Kazumasa Yanagisawa
  • Publication number: 20100264735
    Abstract: Objects of the invention are to minimize power consumption while maintaining the required information processing capabilities of an LSI chip by supplying multiple voltages to the LSI chip such that its circuit blocks receive necessary voltages and to prevent an increase in the chip area of the LSI chip and performance degradation of signal wires, which may result from the supply of the multiple voltages, by reducing the number of power supply wires. In an LSI chip to which two voltages are supplied, high voltage wires are more densely spaced than low voltage wires. By selectively applying voltages based on circuit block performance, it is possible to reduce power consumption while maintaining the amount of information processed by the LSI chip.
    Type: Application
    Filed: April 13, 2010
    Publication date: October 21, 2010
    Inventors: Masanao YAMAOKA, Kenichi Osada, Yasuhiro Fujimura, Tetsuya Fukuoka, Ryo Nishino
  • Patent number: 7808045
    Abstract: The present invention provides a high speed and low power consumption LSI operable in a wide temperature range in which a MOS transistor having back gates is used specifically according to operating characteristics of a circuit. In the LSI, an FD-SOI structure having an embedded oxide film layer is used and a lower semiconductor region of the embedded oxide film layer is used as a back gate. A voltage for back gates in the logic circuits having a small load in the logic circuit block is controlled in response to activation of the block from outside of the block. Transistors, in which the gate and the back gate are connected to each other, are used for the circuit generating the back gate driving signal, and logic circuits having a heavy load such as circuit block output section, and the back gates are directly controlled according to the gate input signal.
    Type: Grant
    Filed: April 26, 2010
    Date of Patent: October 5, 2010
    Assignee: Renesas Electronics Corporation
    Inventors: Takayuki Kawahara, Masanao Yamaoka
  • Publication number: 20100201429
    Abstract: The present invention provides a high speed and low power consumption LSI operable in a wide temperature range in which a MOS transistor having back gates is used specifically according to operating characteristics of a circuit. In the LSI, an FD-SOI structure having an embedded oxide film layer is used and a lower semiconductor region of the embedded oxide film layer is used as a back gate. A voltage for back gates in the logic circuits having a small load in the logic circuit block is controlled in response to activation of the block from outside of the block. Transistors, in which the gate and the back gate are connected to each other, are used for the circuit generating the back gate driving signal, and logic circuits having a heavy load such as circuit block output section, and the back gates are directly controlled according to the gate input signal.
    Type: Application
    Filed: April 26, 2010
    Publication date: August 12, 2010
    Inventors: Takayuki KAWAHARA, Masanao Yamaoka
  • Publication number: 20100188887
    Abstract: The invention provides a semiconductor integrated circuit device provided with an SRAM that satisfies the requirements for both the SNM and the write margin with a low supply voltage. The semiconductor integrated circuit device include: multiple static memory cells provided in correspondence with multiple word lines and multiple complimentary bit lines; multiple memory cell power supply lines that each supply an operational voltage to each of the multiple memory cells connected to the multiple complimentary bit lines each; multiple power supply circuits comprised of resistive units that each supply a power supply voltage to the memory cell power supply lines each; and a pre-charge circuit that supplies a pre-charge voltage corresponding to the power supply voltage to the complimentary bit lines, wherein the memory cell power supply lines are made to have coupling capacitances to thereby transmit a write signal on corresponding complimentary bit lines.
    Type: Application
    Filed: March 29, 2010
    Publication date: July 29, 2010
    Inventors: Noriaki Maeda, Yoshihiro Shinozaki, Masanao Yamaoka, Yasuhisa Shimazaki, Masanori Isoda, Koji Nii
  • Publication number: 20100182076
    Abstract: A semiconductor integrated circuit device achieving an active state in which a high speed operation is performed and an inactive state in which a low leakage state is retained while an internal logical state is retained, and a transition between the two states can be achieved at high speed with low noise and low power. A power control circuit provided between a first power-supply line for providing a first external power-supply voltage and a second power-supply line for providing a second external power-supply voltage includes an output MOSFET. A constant OFF current flows in the MOSFET even if a gate and a source of the output MOSFET are put in the same voltage, and a threshold voltage of the output MOSFET is smaller than that of an internal circuit MOSFET.
    Type: Application
    Filed: January 18, 2010
    Publication date: July 22, 2010
    Inventors: Hiroyuki MIZUNO, Kiyoo ITOH, Masanao YAMAOKA
  • Publication number: 20100177580
    Abstract: Even when memory capacity of a memory that uses a replica bit-line is made higher, fluctuations of a generating timing of a sense-amplifier enable signal are reduced. A semiconductor integrated circuit device comprises a plurality of word lines, a plurality of bit-lines, a plurality of ordinary memory cells, an access control circuit, a plurality of sense-amplifiers, first and second replica bit-lines, first and second replica memory cells, and first and second logic circuits. The first and second replica memory cells are connected to the first and second replica bit-lines, respectively; inputs of the first and second logic circuits are connected to the first and second replica bit-lines, respectively; a sense-amplifier enable signal is generated from an output of the second logic circuit; and this signal is supplied to a plurality of sense-amplifiers.
    Type: Application
    Filed: January 14, 2010
    Publication date: July 15, 2010
    Inventors: Shigenobu Komatsu, Masanao Yamaoka, Noriaki Maeda, Masao Morimoto, Yasuhisa Shimazaki