Tri-state (i.e., High Impedance As Third State) Patents (Class 326/56)
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Publication number: 20110169526Abstract: An electronic integrated circuit includes a signal path connected between the functional logic (15) thereof and an external output terminal. The signal path includes a switch (S), a bus holder circuit (121B), and an output buffer (19).Type: ApplicationFiled: March 23, 2011Publication date: July 14, 2011Applicant: TEXAS INSTRUMENTS INCORPORATEDInventor: Lee D. Whetsel
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Patent number: 7969196Abstract: Method and apparatus are provided for buffering a data signal to a low voltage logic device. A circuit for buffering the data signal to the low voltage logic device includes an output buffer and an N-type transistor. The output buffer has an input and an output, where the input is configured to receive the data signal. The output buffer is configured to produce an output signal based on the data signal, and the output signal has a maximum potential. The N-type transistor has a source coupled to the output, a drain configured to couple to the low voltage logic device, and a gate configured to receive a bias potential, where the bias potential is greater than the maximum potential.Type: GrantFiled: January 5, 2010Date of Patent: June 28, 2011Assignee: Freescale Semiconductor, Inc.Inventors: Paul T. Bennett, John M. Pigott
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Patent number: 7948269Abstract: In one embodiment, an output driver is disclosed. The output driver has a first driving device (Q1) that has a first terminal coupled to a bus line terminal, and a second driving device (Q2) that has a first terminal coupled to the bus line terminal. The first driving device (Q1) is configured to couple the bus line terminal to a reference voltage when activated by a first control signal, and the second driving device (Q2) is configured to couple the bus line terminal to a first supply voltage (Vcc) when the second driving device (Q2) is activated by a second control signal. The output driver also has a controller configured to activate the second control signal after the first control signal is deactivated. The second control signal remains active for a first fixed period of time.Type: GrantFiled: January 20, 2009Date of Patent: May 24, 2011Assignee: XILINX, Inc.Inventors: Richard S. Ballantyne, Mark Paluszkiewicz, Henry E. Styles, Ralph D. Wittig
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Publication number: 20110084729Abstract: One interface chip and a plurality of core chips are electrically connected via a plurality of through silicon vias. A data signal of a driver circuit is input into the core chip via any one of the through silicon vias. An output switching circuit activates any one of tri-state inverters and selects one of the through silicon vias. The tri-state inverters amplify the data signal and transmit it to the through silicon via. Similarly, an input switching circuit activates any one of tri-state inverters. These tri-state inverters also amplify the data signal transmitted from the through silicon via and supply it to the receiver circuit.Type: ApplicationFiled: October 6, 2010Publication date: April 14, 2011Applicant: ELPIDA MEMORY, INC.Inventor: Hideyuki Yoko
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Patent number: 7915926Abstract: A semiconductor chip includes a plurality of pads, input circuits or output circuits that are electrically connected to the pads, a main control unit that outputs a read access signal, the read access signal controlling reading of signals from an external circuit or an internal circuit, and activation control units that control activation of the input circuits or the output circuits that are electrically connected to the pads based on the read access signal, the pads receiving the signals from the external circuit or the internal circuit.Type: GrantFiled: May 3, 2010Date of Patent: March 29, 2011Assignee: Renesas Electronics CorporationInventors: Hideo Isogai, Kentarou Tanaka
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Patent number: 7911229Abstract: Parasitic static leakage current through input terminals of bus-accessing multiplexers is minimized by automatically forcing as many as practical of the bus lines into a high impedance state where all drivers of the lines are in a high impedance output state. Thus parasitic current sinking or current sourcing leakage paths through the bus-accessing multiplexers are cut off. The method is of particular utility in a low power FPGA that desirable has low static current leakage when in a static state.Type: GrantFiled: September 26, 2008Date of Patent: March 22, 2011Assignee: Siliconblue Technologies CorporationInventor: Andrew Ka Lab Chan
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Publication number: 20110006808Abstract: Input/Output (I/O) pin circuits, devices, methods and systems are implemented in various fashions. According to one such method, a valid signal level is provided for a pin of an integrated circuit (IC) die. Responsive to a reset signal, a first mode (304) is entered where one of a pull-up circuit or pull-down circuit is enabled (308, 310) to set the pin to the valid signal level. A change in signal level of the pin that is a deviation from the valid signal level is detected (312). Responsive to detecting the change, a second mode (314) is entered where the one of a pull-up circuit or pull-down circuit is disabled (316).Type: ApplicationFiled: March 16, 2009Publication date: January 13, 2011Applicant: NXP B.V.Inventor: Robert de Gruijl
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Patent number: 7868649Abstract: A processing unit carries out a predetermined data processing on the data in a storage unit. The storage unit is connected to the processing unit with a plurality of connecting lines. A voltage generating unit is connected to each of the connecting lines via a corresponding termination resistor and that generates a termination voltage to be applied to the connecting lines. An interrupting unit is connected between the connecting lines and the termination resistors, and it applies or does not apply the termination voltage to the connecting lines depending on a data processing state of the processing unit.Type: GrantFiled: September 8, 2008Date of Patent: January 11, 2011Assignee: Ricoh Company, LimtedInventor: Satoshi Tanaka
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Patent number: 7868647Abstract: A semiconductor device includes a plurality of pads configured to receive a plurality of external signals, an internal circuit configured to perform a predetermined internal operation in response to one of the external signals that is inputted through one of the plurality of pads, and a signal transferring unit configured to receive the external signal, output the external signal to an internal circuit an output signal during a normal mode, and output a fixed signal regardless of changes in the external signal to the internal circuit in a test mode.Type: GrantFiled: December 24, 2008Date of Patent: January 11, 2011Assignee: Hynix Semiconductor Inc.Inventors: Tae-Sik Yun, Kang-Seol Lee
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Patent number: 7868656Abstract: An apparatus for controlling a hot plug bus slot on a bus has an input for receiving a set of float signals (i.e., the set may have one or more float signals), and a driver having an output electrically couplable with the bus. The apparatus also has float logic operatively coupled with the input. The float logic is responsive to the set of float signals to cause the output to float at a high impedance in response to receipt of the set of float signals.Type: GrantFiled: May 11, 2009Date of Patent: January 11, 2011Assignee: SGI International, Inc.Inventors: Bruce A. Strangfeld, Thomas E. McGee
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Publication number: 20100327908Abstract: An integrated circuit includes switching circuits for selectively connecting the bond pads to functional core logic and isolating the bond pads from second conductors, and the switch circuits for selectively connecting the bond pads to the second conductors to provide bi-directional connections between the bond pads on opposite sides of the substrate and isolating the bond pads from the functional core logic.Type: ApplicationFiled: August 31, 2010Publication date: December 30, 2010Applicant: TEXAS INSTRUMENTS INCORPORATEDInventor: Lee D. Whetsel
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Patent number: 7859294Abstract: An arrangement and method of reducing power in bidirectional I/O ports includes driving an input signal from an I/O port by asserting a high impedance (Hi-Z) signal to an output drive, driving an output signal from the I/O port by refraining from asserting a Hi-Z signal to an output driver, and feeding back the output signal to an input driver when driving the output signal. The method can float the I/O port when the Hi-Z signal is asserted on the output driver or drive the I/O port as an input when the Hi-Z signal is asserted on the output driver. The method can refrain from floating a signal back into the I/O port when driving a signal out by driving a constant logical zero back into the I/O port or driving a constant logical one back or by maintaining a last value driven.Type: GrantFiled: January 22, 2009Date of Patent: December 28, 2010Assignee: Xilinx, Inc.Inventor: Jesse H. Jenkins, IV
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Patent number: 7843220Abstract: An integrated circuit comprises a processor, a controller and plural terminals. Each terminal constitutes a connection between the integrated circuit and a peripheral device. Each terminal is connected to a logic circuit on the integrated circuit by a respective IO cell in series connection with a respective IO isolation circuit and wherein the controller is operable on power up of the integrated circuit to activate a reset state and to release the reset state prior to releasing IO isolation by one or more of the IO isolation circuits. Each IO isolation circuit may be arranged so that a default state of the IO isolation circuit is a state in which the IO cell is isolated from the logic circuit. The IO isolation circuits may be controllable by software, for instance a driver for a peripheral device connected to the terminal associated with the IO isolation circuit. Plural IO isolation circuits may be connected so as to be commonly controllable by a single control signal from the controller.Type: GrantFiled: December 22, 2006Date of Patent: November 30, 2010Assignee: Nokia CorporationInventors: Pasi Kolinummi, Klaus Melakari, Marko Winblad
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Patent number: 7825689Abstract: An exemplary functional input sequential circuit for reducing the setup time of input signals. The functional sequential circuit includes a tri-state inverter having an input signal and two control signals. The transmission circuit receives a control signal from a combinational logic circuit that performs a logical operation on a second input signal and a clock signal. The output of the transmission circuit is coupled to a digital storage element. Further, a control circuit is coupled to the digital storage element in order to force a value on the digital storage element when no input signal is received from the transmission circuit. The control circuit is also controlled by the second input signal and a clock signal.Type: GrantFiled: August 14, 2009Date of Patent: November 2, 2010Assignee: Texas Instruments IncorporatedInventors: Mahesh Ramdas Vasishta, Pavan Vithal Torvi, Sonal Rattnam Sarthi, Badarish Mohan Subbannavar
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Patent number: 7814243Abstract: In one embodiment, payload of multiple threads between intellectual property (IP) cores of an integrated circuit are transferred, by buffering the payload using a number of order queues. Each of the queues is guaranteed access to a minimum number of buffer entries that make up the queue. Each queue is assigned to a respective thread. A number of buffer entries that make up any queue is increased, above the minimum, by borrowing from a shared pool of unused buffer entries on a first-come, first-served basis. In another embodiment, an interconnect implements a content addressable memory (CAM) structure that is shared storage for a number of logical, multi-thread ordered queues that buffer requests and/or responses that are being routed between data processing elements coupled to the interconnect. Other embodiments are also described and claimed.Type: GrantFiled: June 1, 2007Date of Patent: October 12, 2010Assignee: Sonics, Inc.Inventor: Stephen W. Hamilton
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Patent number: 7786758Abstract: A tristate buffer circuit includes a tristate buffer switchable into a high impedance state in response to configuration signal, a delay stage delays the an input signal to the tristate buffer and a gating stage having inputs for the input signal, a delayed input signal and an asynchronous tristate control signal and an output supplying the configuration signal to the tristate buffer. The gating stage sets the configuration signal to the high impedance mode only when the tristate control signal is set and the input signal and the delayed input signal have logic levels indicating that no signal transition of the input signal propagates within the delay stage. Depending upon signal polarity, the input signal and the delayed input signal are required to have the same digital state or opposite digital states.Type: GrantFiled: October 9, 2008Date of Patent: August 31, 2010Assignee: Texas Instruments IncorporatedInventor: Ruediger Kuhn
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Patent number: 7779179Abstract: An interface controller is connected to a host apparatus and a memory, and receiving multiple responses to one request. The interface controller includes a packet generation unit which adds header data to a request issued by the host apparatus to generate a request packet and outputs the request packet to the memory, a receive buffer which stores a response packet with respect to the request packet, a protocol generation unit which generates a response according to a prescribed protocol based on the response packet stored in the receive buffer, and outputs the response to the host apparatus, a maximum division number calculation unit which calculates a maximum division number of the request issued by the host apparatus, and a request issue control unit which gives a request issue permission to the host apparatus based on the maximum division number calculated by the maximum division number calculation unit, a maximum division number of processed request and a maximum division number of processed response.Type: GrantFiled: June 30, 2008Date of Patent: August 17, 2010Assignee: Kabushiki Kaisha ToshibaInventor: Takuya Sekine
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Patent number: 7768304Abstract: Nanotube-based logic circuitry is disclosed. Tri-stating elements add an enable/disable function to the circuitry. The tri-stating elements may be provided by nanotube-based switching devices. In the disabled state, the outputs present a high impedance, i.e., are tri-stated, which state allows interconnection to a common bus or other shared communication lines. In embodiments wherein the components are non-volatile, the inverter state and the control state are maintained in the absence of power. Such an inverter may be used in conjunction with and in the absence of diodes, resistors and transistors or as part of or as a replacement to CMOS, biCMOS, bipolar and other transistor level technologies.Type: GrantFiled: October 30, 2007Date of Patent: August 3, 2010Assignee: Nantero, Inc.Inventor: Claude L. Bertin
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Publication number: 20100109703Abstract: To provide an output control circuit having a small circuit scale that still operates stably at high speed, an output control circuit includes a first inverter and a second inverter, connected in series for outputting signals at an inverted voltage level of an input signal, a first output unit, for which output is controlled based on a voltage level of a signal output by the second inverter, a third inverter, an output of which is connected to an output of the first inverter, for outputting a signal at an inverted voltage level of a signal output by the second inverter, and a second output unit for which output is controlled based on a voltage level of a signal output by the first inverter and a voltage level of a signal output by the third inverter.Type: ApplicationFiled: January 12, 2010Publication date: May 6, 2010Applicant: Panasonic CorporationInventor: Daisuke MATSUOKA
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Publication number: 20100079166Abstract: Parasitic static leakage current through input terminals of bus-accessing multiplexers is minimized by automatically forcing as many as practical of the bus lines into a high impedance state where all drivers of the lines are in a high impedance output state. Thus parasitic current sinking or current sourcing leakage paths through the bus-accessing multiplexers are cut off. The method is of particular utility in a low power FPGA that desirable has low static current leakage when in a static state.Type: ApplicationFiled: September 26, 2008Publication date: April 1, 2010Inventor: Andrew Ka Lab CHAN
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Patent number: 7688109Abstract: The object of the present invention is to appropriately constitute such a semiconductor integrated circuit that mounts a plurality of semiconductor chips thereon so as to increase storage capacity. A semiconductor chip, including: a chip enable buffer circuit which outputs a chip enable signal in response to an output command of the chip enable signal; a standard chip enable pad which receives the output command; a first extension pad which supplies a first extension chip enable signal to the chip enable buffer circuit; a second extension pad which supplies a second extension chip enable signal to the chip enable buffer circuit; a first option pad which receives a first option signal; and a second option pad which receives a second option signal, is constituted.Type: GrantFiled: June 11, 2008Date of Patent: March 30, 2010Assignee: NEC Electronics CorporationInventors: Junji Monden, Naoichi Kawaguchi
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Patent number: 7667489Abstract: A voltage regulator and method of voltage regulation for a power-on reset condition are described. Voltage regulation control signals responsive to the power-on reset condition are obtained. The control signals are generated with a first voltage to be associated with a second voltage to provide a first power-on-reset signal and a second power-on-reset signal which are opposite in state to one another. A portion of driver logic is tri-stated responsive to the control signals, and the second power-on-reset signal to at least impede supply to supply current leakage. Voltage is pulled up on a first output port and a second output port of the driver logic responsive to the first power-on-reset signal. A portion of a semiconductor substrate is electrically coupled to a higher one of a first voltage and a second voltage responsive to the pulling up to at least further impede the supply to supply current leakage.Type: GrantFiled: October 26, 2007Date of Patent: February 23, 2010Assignee: Xilinx, Inc.Inventor: Narasimhan Vasudevan
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Patent number: 7667491Abstract: Method and apparatus are provided for buffering a data signal to a low voltage logic device. A circuit for buffering the data signal to the low voltage logic device includes an output buffer (12) having first and second inputs and an output and at least one N-type isolation transistor (13, 19) having a source coupled to one or both of the second input and the output. The first input receives the data signal, the second input receives a supply potential, and the output couples to the low voltage logic device. The isolation transistor has a drain for receiving a first potential and is configured to supply a second potential to the output buffer when the gate receives a bias potential. The second potential based on the first potential. The bias potential is greater than the supply potential.Type: GrantFiled: February 24, 2006Date of Patent: February 23, 2010Assignee: Freescale Semiconductor, Inc.Inventors: Paul T. Bennett, John M. Pigott
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Publication number: 20100001761Abstract: A single terminal is used to configure an integrated circuit into one of three states. A circuit within the integrated circuit is coupled to the terminal and determines whether the terminal: 1) is coupled by a low impedance to a voltage source, or 2) is coupled by a medium impedance to the voltage source, or 3) is floating or substantially floating. The circuit asserts a first digital logic signal when the circuit determines that the terminal is coupled by the low impedance to the voltage source. The circuit asserts a second digital logic signal when the circuit determines that the terminal is coupled by the medium impedance to the voltage source. The circuit asserts a third digital logic signal when the circuit determines that the terminal is floating or substantially floating. The terminal and circuit are particular suited for use in a Power Management Unit (PMU) Integrated Circuit.Type: ApplicationFiled: July 2, 2008Publication date: January 7, 2010Inventors: Quang Khanh Dinh, Gary M. Hurtz, Steven Huynh
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Patent number: 7622953Abstract: A test circuit according to the present invention performs a test of a first tri-state device and a second tri-state device having their outputs connected to the same node, and includes: a test output terminal; and a test unit operable to output a first logical value or a second logical value to the test output terminal according to whether the voltage of the node is higher or lower than a threshold value, and the test unit converts the intermediate potential occurring at the node into the first logical value and outputs the first logical value to the test output terminal when the first tri-state device outputs a high level signal to the node and the second tri-state device outputs a low level signal to the node.Type: GrantFiled: May 3, 2007Date of Patent: November 24, 2009Assignee: Panasonic CorporationInventor: Genichiro Inoue
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Patent number: 7567094Abstract: A CMOS driver circuit is configured to provide a tri-state condition after a predetermined number of like-valued data bits have been transmitted, reducing the presence of intersymbol interference (ISI) along a transmission channel. In situations where the transmission channel is bandwidth-limited, the use of the tri-stating technique allows for the complete transition to the supply rails during the given bit period.Type: GrantFiled: May 25, 2007Date of Patent: July 28, 2009Assignee: Lightwire Inc.Inventor: Kalpendu Shastri
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Patent number: 7541835Abstract: Techniques and circuits for ensuring undefined control signals are not inadvertently driven onto a bus due to core logic and I/O logic supply voltages reaching final voltage levels at different times are provided. According to some embodiments, an internal voltage supply sense circuit may monitor a level of a voltage supply that powers core logic that generates control signals to be driven on I/O pads. The sense circuit may generate one or more control signals used to keep I/O pads in a high impedance state.Type: GrantFiled: December 8, 2005Date of Patent: June 2, 2009Assignee: NVIDIA CorporationInventors: Ashfaq R. Shaikh, Chang Hee Hong, Ting-Sheng Ku
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Patent number: 7535256Abstract: A cross-level digital signal transmission device between two systems for cross-level digital signal transmission. Bi-directional symmetrical transmission is achieved without using additional control signals, and use of the transmission signal itself eliminates the positive feedback loop. Thus, neither additional control signals nor resulting unsymmetrical circuits need be provided.Type: GrantFiled: September 3, 2003Date of Patent: May 19, 2009Assignee: Industrial Technology Research InstituteInventors: Yuh-Fwu Chou, Tshaw-Chuang Chen, Po-Yin Tseng, Kuo-Kuang Peng, Mei-Fang Huang, Ho-Yin Pun
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Publication number: 20090096483Abstract: A tristate buffer circuit includes a tristate buffer switchable into a high impedance state in response to configuration signal, a delay stage delays the an input signal to the tristate buffer and a gating stage having inputs for the input signal, a delayed input signal and an asynchronous tristate control signal and an output supplying the configuration signal to the tristate buffer. The gating stage sets the configuration signal to the high impedance mode only when the tristate control signal is set and the input signal and the delayed input signal have logic levels indicating that no signal transition of the input signal propagates within the delay stage. Depending upon signal polarity, the input signal and the delayed input signal are required to have the same digital state or opposite digital states.Type: ApplicationFiled: October 9, 2008Publication date: April 16, 2009Inventor: Ruediger Kuhn
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Publication number: 20080303548Abstract: An I/O buffer section is provided with a status setting circuit. The status setting circuit arbitrarily sets a signal state of an I/O terminal according to a combination of control signals stored in a setting register. Thus, the I/O buffer section is temporarily set to a Hi-Z state by the status setting circuit even in the case of the I/O terminal originally set to a signal holding state. Consequently, a leak test for testing whether the I/O buffer section is good or bad, can be performed, and the reliability of a semiconductor device can be enhanced.Type: ApplicationFiled: August 11, 2008Publication date: December 11, 2008Inventors: Fumiki KAWAKAMI, Naoki Yada
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Patent number: 7451238Abstract: A flexible electronic asset management system using Ethernet connectivity for electronic devices is presented. The invention enables multiple electronic devices to be controlled, monitored, and accessed from any browser connected to a computer network. A flattened stack approach is used to process network packet data. The flattened stack approach treats the network packet as a single string of data and uses the first few bytes of information to decide whether to drop or process the incoming data thus providing for faster network traffic processing. Since the lowest layer of the OSI stack has knowledge of what applications are active in the upper layers, the flattened stack allows the packet to be discarded at the earliest possible point so no processing power is wasted. The flattened stack also organizes its check/processing based on the raw data stream thus minimizing buffer requirements and providing for easier implementation into hardware.Type: GrantFiled: October 3, 2003Date of Patent: November 11, 2008Assignee: RGB Systems, Inc.Inventor: Brian Richard Taraci
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Publication number: 20080258768Abstract: A method of operating an electronic device having an output driver with on die termination legs ODT, and non-ODT legs, includes the step of selectively tri-stating tuning transistors (ZQ trim devices) in the legs as a function of the operational state of the output driver. The tri-stating step is performed such that when a leg is not being utilized, the tuning transistors in the unused leg are placed in a tri-state. For example, during an ODT mode of the output driver, the tuning transistors in the non-ODT legs are tri-stated. During a READ mode of the output driver, the tuning transistors in the ODT legs are tri-stated. During a HiZ mode of the output driver, the tuning transistors in both legs are tri-stated. Tri-stating the tuning transistors in the unused output driver legs can reduce DQ pin capacitance by a total of approximately (Cgd+Cgs+Cgb).Type: ApplicationFiled: April 21, 2007Publication date: October 23, 2008Inventor: Raghukiran Sreeramaneni
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Patent number: 7436207Abstract: An integrated circuit device having at least one bond pad is coupled to a selectable plurality of input-output functionalities, e.g., an oscillator input, an analog input, an analog output, a digital input and a digital output. These analog, digital and oscillator functionalities may selectably share the same integrated circuit package external connection.Type: GrantFiled: February 2, 2007Date of Patent: October 14, 2008Assignee: Microchip Technology IncorporatedInventors: J. Clark Rogers, Bryan Kris
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Patent number: 7432739Abstract: A low voltage complementary metal oxide semiconductor (CMOS) process tri-state buffer includes a logic device, a biasing device and a switch device. The logic device receives an input signal and an enable signal and generates a first control signal and a second control signal. The biasing device receives the first control signal and thus controls a voltage level of a third control signal. The switch device receives the second and third control signals and respectively couples an output terminal to a first external voltage source and a second external voltage source when the second and third control signals are enabled. When the enable signal is disabled, the second and third control signals are simultaneously disabled so that the output terminal is floating with respect to the first and second external voltage sources and the output terminal is held in a high impedance state.Type: GrantFiled: October 27, 2006Date of Patent: October 7, 2008Assignee: Macronix International Co., Ltd.Inventors: Tzung-Shen Chen, Ti-Wen Chen, Chun-Yu Liao
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Patent number: 7432731Abstract: An embodiment may comprise memory with a memory array, a resistor coupled to a reference voltage, on die termination circuitry coupled with the resistor, and an input coupled to the on die termination circuitry and coupled with the memory array, the input to receive a calibration command to stop use of the input and the memory array and calibrate the on die termination circuitry with the resistor coupled to the reference voltage. Other embodiments are disclosed herein.Type: GrantFiled: June 30, 2005Date of Patent: October 7, 2008Assignee: Intel CorporationInventors: Kuljit S. Bains, Navneet Dour, Hany Fahmy, George Vergis, Christopher E. Cox
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Publication number: 20080231320Abstract: Nanotube-based logic circuitry is disclosed. Tri-stating elements add an enable/disable function to the circuitry. The tri-stating elements may be provided by nanotube-based switching devices. In the disabled state, the outputs present a high impedance, i.e., are tri-stated, which state allows interconnection to a common bus or other shared communication lines. In embodiments wherein the components are non-volatile, the inverter state and the control state are maintained in the absence of power. Such an inverter may be used in conjunction with and in the absence of diodes, resistors and transistors or as part of or as a replacement to CMOS, biCMOS, bipolar and other transistor level technologies.Type: ApplicationFiled: October 30, 2007Publication date: September 25, 2008Applicant: NANTERO, INC.Inventor: Claude L. BERTIN
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Publication number: 20080224733Abstract: The inventions herein are directed to an inventive bus keeper and logic circuit for use with an I/O circuit, for example, for use on the receiver side of the I/O buffer circuit. The inventive circuit connects one data line of an IC function to one line of a tri-state bus (one bit of data per bus line or wire). The bus keeper and logic control circuit is maintained in isolation from I/O functional driver and is responsive to a tri-state signal (TS), normally provided by the IC or SOC, or the I/O circuit during normal I/O receiver side operation. The inventive bus keeper and logic circuit selectively enables any of a tri-state state, a pull-up state, pull-down state and bus keep mode state at the driver output pad in the presence of the tri-state enable signal, and is disabled when the I/O bus drive buffer circuit is in drive mode.Type: ApplicationFiled: March 12, 2007Publication date: September 18, 2008Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Bret R. Dale, Darin J. Daudelin, Todd M. Fisher, Douglas W. Stout
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Publication number: 20080218209Abstract: The present invention relates to a device for controlling a state of a terminal with respect to mobility management, and a method thereof. The state of the terminal includes a disconnected state and a connected state, the connected state includes an active state and an idle state, and the active state includes an active sub-state and a standby sub-state. The terminal in the active state updates location information for each cell, and the terminal in the idle state updates the location information for each radio access network registration area including a plurality of cells. The terminal in the active sub-state performs a handover when leaving a current cell. The terminal in the standby sub-state determines a quality of service (QoS) of packet data, and performs the handover or is set to be in the idle state according to the determined QoS.Type: ApplicationFiled: August 23, 2006Publication date: September 11, 2008Applicant: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTEInventors: Kyoung-Seok Lee, Soo-Jung Jung, Kang-Hee Kim, Soon-Yong Lim, Byung-Han Ryu, Jae-Heung Kim, Jeong-Im Kim, Geon-Min Yeo
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Patent number: 7414434Abstract: An input circuit is provided that can identify three states of an external signal without complicated voltage adjustment and that can reduce the power consumption in a standby state.Type: GrantFiled: September 16, 2005Date of Patent: August 19, 2008Assignee: Rohm Co., Ltd.Inventor: Takashi Fujimura
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Patent number: 7403036Abstract: As a data bus control enable signal is set to “H,” a PMOS turns on when a bi-directional bus is not in use (i.e., when a data bus active signal is “L”), so that the bi-directional bus is pulled down through a pull-down resistor. When the data bus control enable signal is set to “L,” the PMOS turns off, thus holding the bi-directional bus in a high-impedance state. By setting the data bus control enable signal in accordance with the specifications of a peripheral device connected thereto, the state of the bi-directional bus can be arbitrarily set when it is inactive.Type: GrantFiled: January 31, 2006Date of Patent: July 22, 2008Assignee: Oki Electric Industry Co., Ltd.Inventors: Kazuhiko Bando, Masanori Inazumi
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Patent number: 7327167Abstract: This document discusses, among other things, a circuit for selectively engaging an output section based on a received data signal. The output is driven to a high-impedance state in anticipation of a possible change in driving agent. An output section includes active transistor elements and a pre-driver.Type: GrantFiled: April 28, 2005Date of Patent: February 5, 2008Assignee: Silicon Graphics, Inc.Inventor: Rodney Ruesch
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Publication number: 20070290718Abstract: In normal operation, an internal circuit 4 operates in synchronism with a clock CK, so that switching operation of the output circuit 2 is performed based on inputted data and an output enable signal. At this point, an output from the internal circuit 4 to a three-state control circuit 3 is forcedly set by state control circuits 5 and 6, whereby different test operations are performed on the output circuit 2.Type: ApplicationFiled: May 22, 2007Publication date: December 20, 2007Inventor: Yoshinori Hashimoto
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Patent number: 7304501Abstract: The hot socket detect circuit of the present invention includes a well bias circuit and three hot socket detect blocks. If the output of any of the three hot socket detect blocks is a digital high signal then the output of the hot socket detect circuit is a digital high signal. The digital high signal indicates that a hot socket condition exists.Type: GrantFiled: October 14, 2005Date of Patent: December 4, 2007Assignee: Altera CorporationInventors: Xiaobao Wang, Khai Q. Nguyen, Chiakang Sung, Bonnie I. Wang
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Patent number: 7288961Abstract: Nanotube-based logic circuitry is disclosed. Tri-stating elements add an enable/disable function to the circuitry. The tri-stating elements may be provided by nanotube-based switching devices. In the disabled state, the outputs present a high impedance, i.e., are tri-stated, which state allows interconnection to a common bus or other shared communication lines. In embodiments wherein the components are non-volatile, the inverter state and the control state are maintained in the absence of power. Such an inverter may be used in conjunction with and in the absence of diodes, resistors and transistors or as part of or as a replacement to CMOS, biCMOS, bipolar and other transistor level technologies.Type: GrantFiled: January 22, 2007Date of Patent: October 30, 2007Assignee: Nantero, Inc.Inventor: Claude L. Bertin
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Patent number: 7276939Abstract: A semiconductor integrated circuit includes an input circuit for taking in signals and an output circuit for outputting signals. The input circuit is so set that the input impedance during input signal transition is lower than the input impedance on other occasions than input signal transition. The output circuit is so set that the driving force during the second half of signal transition is lower than the driving force during the first half of transition. Such setting that the input impedance during input signal transition is lower than the input impedance on other occasions than input signal transition reduces reflected waves during input signal transition. Such setting that the driving force during the second half of signal transition is lower than the driving force during the first half of transition suppresses production of reflected waves during the second half of signal transition.Type: GrantFiled: January 20, 2003Date of Patent: October 2, 2007Assignee: Renesas Technology Corp.Inventors: Takayuki Noto, Tomoru Sato, Hiroyuki Yamauchi
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Patent number: 7265575Abstract: Nanotube based logic driver circuits. These include pull-up driver circuits, push-pull driver circuits, tristate driver circuits, among others. Under one embodiment, an off-chip driver circuit includes a differential input having first and second signal links, each coupled to a respective one of two differential, on-chip signals. At least one output link is connectable to an off-chip impedance load, and at least one switching element has an input node, an output node, a nanotube channel element, and a control structure disposed in relation to the nanotube channel element to controllably form and unform an electrically conductive channel between said input node and said output node. The input node is coupled to a reference signal and the control structure is coupled to the first and second signal links. The output node is coupled to the output link, and the channel element is sized to carry sufficient current to drive said off-chip impedance load.Type: GrantFiled: January 16, 2007Date of Patent: September 4, 2007Assignee: Nantero, Inc.Inventor: Claude L. Bertin
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Patent number: 7259588Abstract: A tri-state detection circuit includes a first input port for receiving a tri-state input signal, a clock input port for receiving a clocking signal, a first output port, a second output port coupled to the first input port, a D-flip-flop and a buffer. The D-flip-flop has a D input, a clock input CLK, and a Q output. The D input is tied high. The clock input CLK is coupled to the first input port. The Q output is coupled to the first output port. The buffer has a buffer input and a buffer output. The buffer input is coupled to the clock input port. The buffer output is coupled to the clock input CLK of the D-flip-flop.Type: GrantFiled: July 29, 2003Date of Patent: August 21, 2007Assignee: Lexmark International Inc.Inventor: Adam Jude Ahne
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Patent number: 7239177Abstract: An off chip driver circuit includes a pre-driver circuit and a driver circuit. Driver data and enable inputs are decoded in the pre-driver circuit to provide independent inputs to pull up and pull down transistors in the driver circuit. The enable input keeps the driver circuit in the active or high impedance modes. A feedback signal generated by the driver output and the driver enable signals controls an inverter circuit within the driver circuit to provide proper biasing conditions at the gate of the pull up transistor. This feed back provides fast switching times for the driver circuit and prevents gate oxide of all the transistors from being overstressed by the external high voltage signal.Type: GrantFiled: April 15, 2005Date of Patent: July 3, 2007Assignee: BAE Systems Information and Electronic Systems Integration Inc.Inventor: Jai P. Bansal
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Patent number: 7208977Abstract: A tristate operating mode setting device is proposed, which is designed for use with an electronic circuit unit for providing the electronic circuit unit with a tristate operating mode setting function, and which is characterized by the utilization of a specially-designed logic circuit and logic control signal generator to allow the electronic circuit unit to be selectively set to one of three different operating modes during startup through a connecting pad that can be externally connected in three different ways. This feature allows one single pad for the provision of three different operating mode settings, whereas prior art is only capable of providing two different settings. The electronic circuit unit is therefore able to use fewer number of pads to provide an increased number of operating mode settings, with the benefit of reducing layout space on circuit board.Type: GrantFiled: June 28, 2005Date of Patent: April 24, 2007Assignee: RDC Semiconductor Co., Ltd.Inventor: Shih-Jen Chuang
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Patent number: 7205793Abstract: The present invention is directed to programmable bidirectional buffers and methods for programming such buffers. One method of according to an aspect of the present invention is a method of configuring a bidirectional buffer including first and second signal nodes. The method includes applying a configuration signal on one of the first and second signal nodes and configuring the buffer responsive to the applied configuration signal.Type: GrantFiled: March 30, 2006Date of Patent: April 17, 2007Assignee: STMicroelectronics, Inc.Inventor: Varghese George