Patents Examined by T. T. Lam
  • Patent number: 5801566
    Abstract: According to the present invention, when a semiconductor device is tested, a signal for test can be set in the semiconductor device at a desired timing. A second delay circuit of the present invention has the same structure as a first delay circuit in a phase lock loop, and receives a control voltage from the phase lock loop so as to generate a clock signal with a frequency according to the control voltage and to delay and output the clock signal. A second pulse generator generates two-phase clocks by using delayed signals generated by the second delay circuit. Switches are used for switching between a system clock output terminal during an actually active time and a system clock output terminal during testing.
    Type: Grant
    Filed: August 5, 1996
    Date of Patent: September 1, 1998
    Assignees: Mitsubishi Electric Semiconductor Software Co., Ltd., Mitsubishi Denki Kabushiki Kaisha
    Inventor: Nobuhiko Tanaka
  • Patent number: 5798667
    Abstract: The clock rate for a device is controlled through the use of integrated circuits which respond to the temperature of the device. Circuitry is added to the integrated circuit device being controlled which changes the clock rate of the device as the device temperature changes. The device clock is thus regulating by the temperature of the device. The way in which the regulation is implemented can be varied, from slowing an internally generated clock rate, or by digitally scaling an external clock input. Synchronous scaling is also provided, such that devices which are connected external to the CPU can still be clocked at the same external rate, but CPU transactions within the CPU may occur at a different rate depending on the CPU's measured temperature. This invention also provides the ability to selectively reduce or stop certain areas of an integrated circuit relative to pending operations or instructions being executed.
    Type: Grant
    Filed: May 16, 1994
    Date of Patent: August 25, 1998
    Assignees: AT&T Global Information Solutions Company, Hyundai Electronics America, Symbios, Inc.
    Inventor: Brian K. Herbert
  • Patent number: 5796282
    Abstract: The present invention provides a latching mechanism for use in high-speed domino logic pipestages. The latching mechanism allows time borrowing across latch boundaries, provides sufficient hold time for the output to be sensed by the next stage, and provides a circuit configuration in which race conditions related to the latching mechanism have inherent positive margin. The latching mechanism of the present invention is applicable to fully self-resetting domino logic, globally resetting domino logic, or any combination thereof. The latching mechanism is a set dominant latch having its set input driven by the output of the last domino logic gate in a pipestage, and having its reset input driven by the output of the last domino logic gate in a pipestage ANDed with a delayed version of the pulsed clock that triggers the domino chain of the pipestage.
    Type: Grant
    Filed: August 12, 1996
    Date of Patent: August 18, 1998
    Assignee: Intel Corporation
    Inventors: Milo David Sprague, Robert J. Murray
  • Patent number: 5793236
    Abstract: An integrated circuit provides for doubled data throughput by clocking data on both edges of an attached clock signal. The circuit includes an upper latch stack, responsive to the clock rising edge, and a lower latch stack responsive to the clock falling edge, each latch stack outputting a respective set and clear signal. An active overlap filter logically ORs the set and clear signals from the upper and lower latch stacks to a third set and clear signal which controls operation of an output latch. Data lines are connected to the upper and lower latch stacks, such that a first data signal is clocked to the circuit output during a clock rising edge transition and a second data signal is clocked to the output during a clock falling edge transition. Filter circuitry between the latch stacks and the output latch ensures that set and clear are not asserted simultaneously, thus providing for "glitch" free operation of the circuit.
    Type: Grant
    Filed: December 13, 1996
    Date of Patent: August 11, 1998
    Assignee: Adaptec, Inc.
    Inventor: Michael T. Kosco
  • Patent number: 5793234
    Abstract: A pulse width modulation (PWM) circuit is disclosed for multiple channels. The circuit allows output pulses of a PWM signal for each channel to be distributed not simultaneously but with a time difference so that the power consumption is temporally distributed.
    Type: Grant
    Filed: May 22, 1996
    Date of Patent: August 11, 1998
    Assignee: LG Semicon Co., Ltd.
    Inventor: Dong Soo Cho
  • Patent number: 5793249
    Abstract: The system and method of enhancing the yield of flash memory circuit is disclosed. The method comprises performing a diagonal erase of a select group of memory cells on a wafer during sort. If the memory cells do not erase in a satisfactory manner, the control voltage applied to the memory cell is adjusted based on the memory cell's erase time. The circuitry for providing the adjustment voltage includes trimming circuitry for an incrementally increasing the applicable control of voltage.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: August 11, 1998
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Jian Chen, Lee E. Cleveland
  • Patent number: 5789957
    Abstract: A flip-flop of the D type capable of loading data asynchronously and comprising two latches, a master and a slave one, connected in series with each other, is characterized in that each of these comprises an interface and selection circuit for input signals transferable in either the synchronous or the asynchronous manner, and a logic gate circuit which is input such signals and, in an asynchronous manner, control signals effective to establish the latch own states.
    Type: Grant
    Filed: August 30, 1996
    Date of Patent: August 4, 1998
    Assignee: SGS-Thomson Microelectronics, S.r.l.
    Inventors: Giona Fucili, Lorenzo Papillo, Andrea Pasquino, Annamaria Rossi, Alberto Gola
  • Patent number: 5789954
    Abstract: The phase of an acquisition clock for a digital oscilloscope is modulated by summing an offset voltage with the output of the phase detector of a delay lock loop. The offset voltage is generated by a digital-to-analog converter which is fed input values by a microprocessor running a number generator routine.
    Type: Grant
    Filed: June 27, 1997
    Date of Patent: August 4, 1998
    Assignee: Hewlett-Packard Co.
    Inventors: Derek E. Toeppen, B. Allen Montijo, Reginald Kellum
  • Patent number: 5789959
    Abstract: Direct voltage and alternating voltage signals are decoupled from a first and a second pair of leads. The pairs of leads each carry an alternating voltage signal and they are subject to a direct voltage between them. A capacitive connection of the leads with the inputs of a signal receiving device allows decoupling of the alternative voltage signal. For decoupling one pole of the direct voltage signal, diodes are provided that are connected to the leads of the respective pair of leads. The diodes are each connected via a respective current source transistor to one terminal for the pole of the direct voltage. The control terminals of the current source transistors are controlled by the center tap of a voltage divider connected between the diodes. The embodiment for direct voltage decoupling is readily integratable.
    Type: Grant
    Filed: September 30, 1996
    Date of Patent: August 4, 1998
    Assignee: Siemens Aktiengesellschaft
    Inventors: Franz Dielacher, Berndt Pilgram, Joerg Hauptmann
  • Patent number: 5786715
    Abstract: A programmable digital frequency multiplier includes either a delay locked loop with an input clock or a ring oscillator which generates multiple phase delayed clock signals having a common frequency equal to that of the input clock and a corresponding number of equidistant phases. In the delay locked loop, a phase comparator compares the phase of the input clock as received by the first inverter circuit with the phase of the output of the last inverter circuit and generates an error signal which is used as a circuit bias control signal for each of the inverter circuits, thereby controlling the phase delay through each inverter circuit. The multiple inverter circuit output signals are individually gated in separate NOR gates with a corresponding number of frequency programming bits.
    Type: Grant
    Filed: June 21, 1996
    Date of Patent: July 28, 1998
    Assignee: Sun Microsystems, Inc.
    Inventor: Sameer D. Halepete
  • Patent number: 5783960
    Abstract: A remote clock signal generation means is provided which allows a plurality of clock signals to be generated remotely at the "leaf" level thereby removing the need to have multiple clock signals at the system, or "tree" level. More particularly, this system is designed for use in an LBIST circuit featuring LSSD master-slave clock control. This disclosure teaches a clock control method and structure in which the master and slave clocks are generated directly from the system clock after the clock powering logic to thereby avoid intrusion or modification effects associated with logical manipulation of the clock signals.
    Type: Grant
    Filed: July 15, 1997
    Date of Patent: July 21, 1998
    Assignee: International Business Machines Corporation
    Inventor: David E. Lackey
  • Patent number: 5781052
    Abstract: A status latch with one-phase control signal is constructed only from purely static gates, thus has great security against interference in the stationary state, and is thus suited in particular for low-voltage operation. In the one-phase latch, the power loss is particularly low due to the lower wiring capacity of the control lines, for which reason it can be advantageously used in particular in digital circuits with high data rates. Advantageously, a low number of transistors is required.
    Type: Grant
    Filed: January 16, 1997
    Date of Patent: July 14, 1998
    Assignee: Siemens Aktiengesellschaft
    Inventor: Ulrich Kleine
  • Patent number: 5777499
    Abstract: An oscillating circuit 30 outputs a signal .o slashed..sub.o whose pulse cycle T is a linear function T=kS+m of a control input value S. A frequency control circuit 10, every time a counter 11 counts a number Nr of pulses of a reference signal .o slashed..sub.r, calculates S=No-m/k, where No is a count of .o slashed..sub.o counted by the counter 12, makes a judgement on convergence of .o slashed..sub.o based upon the difference between input and output values of a register 14, makes the register 14 hold S, updates Nr=S+m/k and clears the counter 12 to 0. A digital phase control circuit 20 judges a advance/delay of the phase of .o slashed..sub.o relative to .o slashed..sub.
    Type: Grant
    Filed: April 10, 1996
    Date of Patent: July 7, 1998
    Assignee: Fujitsu Limited
    Inventor: Toru Takaishi
  • Patent number: 5777502
    Abstract: A circuit (10) and method for protecting the gate-source elements of an FET includes a circuit (12, 13) for providing a pullup gate drive current to the gate-source elements. A voltage sensing circuit (45) senses a voltage on the gate-source elements to produce an indication if the voltage has exceeded a predetermined level. The voltage sensing circuit (45) has a zener diode (48) and a current mirror with first (52) and second (51) current flow paths. The zener diode (48) and the first flow path (52) are connected between the gate and a source of the FET. When a voltage between the gate and source of the FET exceeds the breakdown voltage of the zener diode (48) and one V.sub.gs in the current mirror, a current flows in the first flow path (52) producing a current flow in the second flow path (51). A circuit (20, 23, 62, 58, 60) reduces the pullup gate drive current in response to the current in the second flow path (51).
    Type: Grant
    Filed: August 7, 1996
    Date of Patent: July 7, 1998
    Assignee: Texas Instruments Incorporated
    Inventors: Wayne T. Chen, Steven C. Jones, Stephen C. Kwan
  • Patent number: 5777498
    Abstract: A circuit that compensates for delays induced by clock generation logic and distributed clock drivers in phase lock loop applications is disclosed. The circuit is a phase lock loop (PLL) which contains a clock synchronization circuit that operates to synchronize a transition edge of a signal generated by a frequency divider against a distributed clock signal generated by a clock output driver of the circuit. The synchronization occurs unless the clock synchronization circuit is disabled.
    Type: Grant
    Filed: December 2, 1996
    Date of Patent: July 7, 1998
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventors: Aldo Giovanni Cometti, R. Frank O'Bleness
  • Patent number: 5774005
    Abstract: A high-performance flip-flop circuit implementation. The flip-flop circuit comprises an "implicit" one-shot to generate a delayed clock output (407). The flip-flop comprises a delay block (405) coupled to a clock input (210). The flip-flop may be a D-type flip-flop. In a positive-edge-triggered embodiment of the flip-flop, a falling edge (540) of the delayed clock output (407) follows a rising edge (544) of a clock signal after a delay period (548). The flip-flop clocks in new data at a data input (205) in response to the clock input (210) during this delay period (548). Data is held in a storage block (450). The flip-flop has extremely good transient characteristics, especially setup and clock-to-output times. The flip-flop consumes no static power.
    Type: Grant
    Filed: August 30, 1996
    Date of Patent: June 30, 1998
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Hamid Partovi, Robert C. Burd, Udin Salim, Frederick Weber, Luigi DiGregorio, Donald A. Draper
  • Patent number: 5774008
    Abstract: Addition is performed by a capacitive coupling or resistive coupling. A quantizing circuit is realized by plurality of thresholding circuits receiving an analog input voltages. Subtraction in performed by two MOSs of anti-polarity inputted analog input voltages to gates.
    Type: Grant
    Filed: December 13, 1996
    Date of Patent: June 30, 1998
    Assignees: Yozan Inc, Sharp Corporation
    Inventors: Guoliang Shou, Sunao Takatori, Makoto Yamamoto
  • Patent number: 5774001
    Abstract: A source synchronous computer system to ensure the capturing of signals transmitted from a first component to a second component. An integrated circuit operating on a core clock signal and an I/O clock signal, the circuit comprising a plurality of data drivers and a plurality of delayed I/O clock generators, wherein the I/O clock generators generate delayed I/O clocks signals that follow the I/O clock signal by a phase multiple of the core clock signal. The integrated circuit outputs data through output nodes that are synchronized with I/O clock signal. By outputting data signals in the I/O clock domain and using the delayed I/O clock signals to synchronize transmission with external components, the integrated circuit ensures that the data signals are valid before the external component latches the data. A set of data signals and a delayed I/O clock are generated from similar drivers to further ensure that the data signal is valid before the external component latches the data.
    Type: Grant
    Filed: December 20, 1995
    Date of Patent: June 30, 1998
    Assignee: Intel Corporation
    Inventors: Thomas J. Mozdzen, Harry Muljono
  • Patent number: 5774015
    Abstract: In a semiconductor integrated circuit for use in a signal processing, each of semiconductor elements contained in a region 101 is composed of a MOS transistor having a short channel length while each of semiconductor elements contained in a region 102 is composed of a MOS transistor having a long channel length. Although the semiconductor elements contained in the region 101 are rapidly operable with a short rising time and a short trailing time, those contained in the region 102 are operable comparatively slow with a long rising time and a long trailing time. Accordingly, it is possible to reduce electromagnetic emissions produced in the region 102.
    Type: Grant
    Filed: December 14, 1995
    Date of Patent: June 30, 1998
    Assignee: NEC Corporation
    Inventor: Kouichi Murakami
  • Patent number: 5774002
    Abstract: A clock recovery circuit is disclosed for recovering the data of a non-return to zero signal received at an optical transceiver. The clock recovery circuit includes an active element mixer for doubling the frequency of the received non-return to zero encoded digital signal. The mixer includes a delay element for delaying the received non-return to zero signal and an exclusive-OR circuit for exclusive-ORing the delayed and received non-return to zero signals. A SAW filter is also provided for recovering a clock from the frequency doubled signal outputted by the mixer.
    Type: Grant
    Filed: April 25, 1997
    Date of Patent: June 30, 1998
    Assignee: Industrial Technology Research Institiute
    Inventors: Song-Yuen Guo, Jin-San Ko