With Clock Input Patents (Class 327/211)
  • Patent number: 7391250
    Abstract: For retaining an output data signal of a data retention cell in a power-saving mode, a slave latch unit of the data retention cell is powered with a real power for preserving the output data signal. The output data signal is furnished backward to an input control circuit of the data retention cell. The data signal furnished to a master latch unit of the data retention cell is controlled to switch between an input data signal and the output data signal by the input control circuit in response to a retention signal. The switching of the data signal for refreshing the master latch unit is delayed by a delay unit of the input control circuit, which functions to make sure that the data-preserving process is properly operated on any transition from the power-saving mode to a power-active mode.
    Type: Grant
    Filed: September 2, 2007
    Date of Patent: June 24, 2008
    Assignee: United Microelectronics Corp.
    Inventor: Fu-Chai Chuang
  • Patent number: 7388416
    Abstract: A latch circuit includes a voltage driven type data reading unit and a voltage driven type data holding unit, and operates based on a clock signal that is supplied from an outside source. The data reading unit reads both a first input data and a second input data, and outputs both a first output data and a second output data based on both the first input data and the second input data, while the data holding unit holds both the first output data and the second output data. Both the first input data and the second input data are differential signals, and both the first output data and the second output data are differential signals that have phases that are inverted.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: June 17, 2008
    Assignee: Fujitsu Limited
    Inventor: Masazumi Marutani
  • Patent number: 7365575
    Abstract: A gated clock logic circuit includes a pulse generator and a precharged latch. The pulse generator generates a pulse signal in response to a clock signal, and the precharged latch generates a gated clock signal in response to the clock signal, the pulse signal, and a control signal.
    Type: Grant
    Filed: November 2, 2005
    Date of Patent: April 29, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Min-Su Kim
  • Patent number: 7362154
    Abstract: A programmable phase frequency divider for space applications is implemented in CMOS technology, and consists of three radiation hardened D-type flip flops and combinational logic circuits to provide the feedback controls that allow programmable frequency division ratios from 1 to 8. The radiation hardened D-type flip flop circuits are designed to keep on running properly at GHz frequencies even after a single event upset (SEU) hit. The novel D-type flip flop circuits each have two pairs of complementary inputs and outputs to mitigate SEU's. The combinational logic circuits are designed to utilize the complementary outputs in such a way that only one of the four dual complementary inputs to any D-type flip flop gets flipped at most after an SEU hit. Therefore, a radiation hardened programmable phase frequency divider that is immune to SEU's is achieved.
    Type: Grant
    Filed: May 18, 2006
    Date of Patent: April 22, 2008
    Assignee: International Business Machines Corporation
    Inventor: William Yeh-Yung Mo
  • Patent number: 7358787
    Abstract: A dual purpose current mode logic (“CML”) latch circuit is provided which includes a CML latch operable to receive at least a pair of differential input data signals and at least one clock signal. The CML latch is operable to generate at least one output signal in accordance with the states of the pair of input differential data signals. A mode control device is operable to receive a mode control signal to operate the CML latch as a buffer or as a latch. In such way, when the mode control signal is inactive, the CML latch generates and latches the output signal at a timing determined by the at least one clock signal, and when the mode control signal is active the CML latch generates the output signal such that the output signal changes whenever the states of the pair of differential input data signals change.
    Type: Grant
    Filed: February 28, 2006
    Date of Patent: April 15, 2008
    Assignee: International Business Machines Corporation
    Inventors: Joseph O. Marsh, Joseph Natonio, James M. Wilson
  • Patent number: 7323911
    Abstract: A differential sense amplifier is described that can be configured as a preamplifier or a latch circuit as triggered by a clock signal connected to a switch circuit. When the clock signal is set at a first signal level, the switch circuit in the differential sense amplifier is activated so that the differential sense amplifier is configured as a preamplifier with a positive feedback circuit. When the clock signal is set at a second signal level, the switch circuit in the differential sense amplifier is deactivated so that the differential sense amplifier is configured as the latch circuit. For one read cycle, the differential sense amplifier operates first as the preamplifier and then as the latch circuit.
    Type: Grant
    Filed: November 21, 2005
    Date of Patent: January 29, 2008
    Assignee: Macronix International Co., Ltd.
    Inventors: Jer Hao Hsu, Tein Yen Wang
  • Patent number: 7323920
    Abstract: In a preferred embodiment, the invention provides a circuit and method for reducing soft error events in latches. A low-pass filter is placed between the output of a forward inverter and the inputs of a feedback keeper. The first and second outputs of the low-pass filter are connected to first and second inputs respectively of the feedback keeper. The only type of diffusion connected to the first output of the low-pass filter is a P-type diffusion. The only type of diffusion connected to the second output of the low-pass filter is an N-type diffusion. The feedback keeper is connected to an input of the forward inverter.
    Type: Grant
    Filed: June 13, 2005
    Date of Patent: January 29, 2008
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Samuel D. Naffziger
  • Patent number: 7301381
    Abstract: A clocked state circuit can include a transmission gate configured to clock an output of a master terminal to an input of a slave terminal responsive to a clock signal or a delayed clock signal coupled to the transmission gate.
    Type: Grant
    Filed: August 1, 2005
    Date of Patent: November 27, 2007
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Young-chul Rhee, Sung-we Cho
  • Patent number: 7265582
    Abstract: A level shifter is provided. The level shifter includes a first input transistor, a second input transistor, a first bias transistor, a second bias transistor, a first switch transistor and a second switch transistor. At the time of change of the signal status, by raising the potential of the body terminal of the first input transistor, the threshold voltage is reduced so that the current flowing through the second input transistor is increased to shorten the time of the change of the signal status.
    Type: Grant
    Filed: December 2, 2004
    Date of Patent: September 4, 2007
    Assignee: TPO Displays Corp.
    Inventors: Wei-Jen Hsu, Ming-Dou Ker, Ying-Hsin Li, An Shih
  • Patent number: 7265589
    Abstract: A dynamic logic gate has a dynamic node pre-charged in response to a pre-charge phase of a clock signal and a logic tree with a plurality of logic inputs for evaluating the dynamic node during an evaluate phase of the clock signal in response to a Boolean combination of the logic inputs. The logic tree has a stacked configuration with at least one multi-gate FEAT device for coupling an intermediate node of the logic tree to the dynamic node in response to a first logic input of the plurality of logic inputs or in response to the pre-charge phase of the clock signal. The multi-gate FEAT device has one gate coupled to the first logic input and a second gate coupled to a complement of the clock signal used to pre-charge the dynamic node.
    Type: Grant
    Filed: June 28, 2005
    Date of Patent: September 4, 2007
    Assignee: International Business Machines Corporation
    Inventors: Ching-Te Chuang, Keunwoo Kim, Jente Benedict Kuang, Kevin John Nowka
  • Patent number: 7265599
    Abstract: A edge triggered flipflop tolerates arbitrarily slow clock edge rates by utilizing complex gates, with weighted transistors, to electrically isolate the master latch from the data inputs, before the master latch and the slave latch are electrically connected together, and to electrically isolate the master latch from the slave latch, before the master latch and the data inputs are electrically connected together.
    Type: Grant
    Filed: November 24, 2004
    Date of Patent: September 4, 2007
    Assignee: National Semiconductor Corporation
    Inventor: Ronald Pasqualini
  • Patent number: 7259605
    Abstract: A pseudo true single phase clock latch (pseudo “TSPC” latch) includes additional circuitry coupled to three previously floating nodes that can lose data depending upon the amount of leakage current associated with these nodes. The additional circuitry, including a positive feedback circuit, improves the performance of a true single phase clock latch circuit at lower frequencies without significant degradation in high frequency operation of the latch.
    Type: Grant
    Filed: October 20, 2004
    Date of Patent: August 21, 2007
    Assignee: STMicroelectronics Pvt. Ltd.
    Inventors: Kallol Chatterjee, Jeet Narayan Tiwari
  • Patent number: 7242235
    Abstract: A flip-flop is configured to operate either in a double data-rate mode or a normal mode. When configured to operate in the double data-rate mode, the flip-flop outputs data on both edges of the applied clock. When configured to operate in the normal mode, the flip-flop outputs data on either the rising or falling edges of the applied clock. In the double data-rate mode, when a first latch disposed in the flip-flop operates in a sampling mode, the second latch disposed in the flip-flop operates in a holding mode to supply the output data, and when the second latch operates in the sampling mode, the first latch operates in the holding mode to supply the output data. Accordingly, with each of the rising or falling edge of the clock, one of the latches supplies an output data.
    Type: Grant
    Filed: February 25, 2005
    Date of Patent: July 10, 2007
    Assignee: Exar Corporation
    Inventor: Nam Duc Nguyen
  • Patent number: 7224197
    Abstract: The present invention discloses a flip-flop implemented with metal-oxide semiconductors using a single low-voltage power supply and a control method thereof, wherein an external control signal is input to a power switch in order to turn on the power switch for an active mode or to turn off the power switch for a sleep mode and inputting an external sleep control signal; the power switch is used to control a combinational circuit to enter into the active or the sleep mode, and the combinational circuit is connected to a virtual power supply; an internal clock signal is separately input to a master stage and a slave stage of the flip-flop, and whether to enter into the sleep mode or the active mode is determined by the voltage level of the internal clock signal. In the present invention, all the logic gates of the combinational circuit are formed of low-threshold CMOS's, which enables the present invention to maintain a given operation speed at a lower voltage.
    Type: Grant
    Filed: August 26, 2005
    Date of Patent: May 29, 2007
    Assignee: National Chung Cheng University
    Inventors: Jinn-Shyan Wang, Hung-Yu Li
  • Patent number: 7212056
    Abstract: A radiation hardened latch is presented. The radiation hardened latch uses two redundant inverter paths to duplicate an input signal. The duplicated inverter paths are coupled with a radiation hardened inverter that will only produce an inverted signal if both input signals have equivalent voltage levels. The radiation hardened inverter and its output signal produce a radiation hardened node that drives either one of the duplicated inverter paths back to an appropriate voltage level in the event of an SET. Because, the radiation hardened node and duplicated inverter paths are isolated, the latch may be optimized for factors such as signal speed and driving strength. These factors may be optimized without affecting radiation hardness. The radiation hardened latch may also be used to build more complex circuits such as a flip-flop.
    Type: Grant
    Filed: October 12, 2005
    Date of Patent: May 1, 2007
    Assignee: Honeywell International Inc.
    Inventor: Vladimir Belov
  • Patent number: 7167033
    Abstract: A data retaining circuit has been disclosed in which, even if a soft error occurs, it is corrected and a normal value can be maintained, the configuration is simple, and high-speed operations are enabled. In this circuit, when a soft error occurs in the data to be put out, it is corrected by a pull-up path or a pull-down path, and when a soft error occurs in the data in the pull-up path or the pull-down path, the error data in the pull-up path or the pull-down path is prevented from affecting each other, as well as turning off the correcting function to prevent the influence on the data to be put out.
    Type: Grant
    Filed: June 15, 2005
    Date of Patent: January 23, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yukio Arima, Takahiro Yamashita, Koichiro Ishibashi
  • Patent number: 7151395
    Abstract: A data retaining circuit has been disclosed in which, even if a soft error occurs, it is corrected and a normal value can be maintained, the configuration is simple, and high-speed operations are enabled. In this circuit, when a soft error occurs in the data to be put out, it is corrected by a pull-up path or a pull-down path, and when a soft error occurs in the data in the pull-up path or the pull-down path, the error data in the pull-up path or the pull-down path is prevented from affecting each other, as well as turning off the correcting function to prevent the influence on the data to be put out.
    Type: Grant
    Filed: June 15, 2005
    Date of Patent: December 19, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yukio Arima, Takahiro Yamashita, Koichiro Ishibashi
  • Patent number: 7132871
    Abstract: A data retaining circuit has been disclosed in which, even if a soft error occurs, it is corrected and a normal value can be maintained, the configuration is simple, and high-speed operations are enabled. In this circuit, when a soft error occurs in the data to be put out, it is corrected by a pull-up path or a pull-down path, and when a soft error occurs in the data in the pull-up path or the pull-down path, the error data in the pull-up path or the pull-down path is prevented from affecting each other, as well as turning off the correcting function to prevent the influence on the data to be put out.
    Type: Grant
    Filed: June 15, 2005
    Date of Patent: November 7, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yukio Arima, Takahiro Yamashita, Koichiro Ishibashi
  • Patent number: 7084683
    Abstract: A differential flip-flop (400) has an output stage (402) with first and second input terminals (X1, X2), first and second output terminals (Q, Qb), a first voltage supply terminal (Vss), a first transistor (435) having a first current-handling terminal connected to the first output terminal (Q), a second current-handling terminal connected to the second output terminal (Qb), and a first control terminal connected to a clock signal (C). A second transistor has a third current-handling terminal connected to the first output terminal (Q), a fourth current-handling terminal connected to the voltage supply terminal (Vss), and a second control terminal connected to a first input terminal (X1) of the output stage. A third transistor (440) has a fifth current-handling terminal connected to the first output terminal (Q), a sixth current-handling terminal connected to the voltage supply terminal (Vss), and a third control terminal connected to the second output terminal (Qb).
    Type: Grant
    Filed: April 30, 2004
    Date of Patent: August 1, 2006
    Assignee: Xilinx, Inc.
    Inventor: Michael A. Nix
  • Patent number: 7068088
    Abstract: In a preferred embodiment, the invention provides a circuit and method for reducing soft error events in latches. The input of a first inverter is connected to the output of a second inverter. The input of a second inverter is connected to the output of the first inverter. When the input to the first inverter is disturbed by a soft error event, a signal tristates the first inverter.
    Type: Grant
    Filed: October 27, 2004
    Date of Patent: June 27, 2006
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: John T. Petersen
  • Patent number: 7023255
    Abstract: A digital latch includes a latch circuit having first and second data inputs, first and second data outputs, and a clock signal input. The latch circuit has a first load value relative to a clock driver when data at the first and second data inputs is non-changing. The latch circuit has a second load value relative to a clock driver when data at the first and second data inputs is changing. The digital latch further includes a load compensation circuit operatively connected to the first and second data inputs of the latch circuit and to the first and second data outputs of the latch circuit.
    Type: Grant
    Filed: June 23, 2004
    Date of Patent: April 4, 2006
    Assignee: Analog Devices, Inc.
    Inventor: Douglas A. Mercer
  • Patent number: 6975151
    Abstract: A latch circuit to perform high-speed input and output operations by reducing a load of an input circuit or an output circuit of the latch circuit. The latch circuit includes four or more inverters connected in a loop to hold a signal, a plurality of input terminals respectively connected to different nodes, and a plurality of output terminals respectively connected to different nodes. At least one input terminal of the latch circuit is used for normal operation of the latch circuit, and at least one input terminal is used for a test operation of the latch circuit. Further, at least one output terminal of the latch circuit is used for normal operation of the latch circuit, and at least one output terminal is used for a test operation of the latch circuit. The latch circuit reduces the number of circuit elements at a connecting point of an input terminal of the latch circuit or at a connecting point of an output terminal of the latch circuit.
    Type: Grant
    Filed: March 26, 2002
    Date of Patent: December 13, 2005
    Assignee: Fujitsu Limited
    Inventor: Hideo Akiyoshi
  • Patent number: 6972605
    Abstract: A high-speed semi-dynamic flip-flop circuit uses a keeper transistor to replace the back-to-back inverter keeper circuit of prior art semi-dynamic flip-flop circuits to avoid the fight between a first node, or OUTBAR node, and the prior art back-to-back inverter keeper circuit. The result is a faster semi-dynamic flip-flop circuit that is also immune to noise.
    Type: Grant
    Filed: March 25, 2004
    Date of Patent: December 6, 2005
    Assignee: Sun Microsystems, Inc.
    Inventor: Swee Yew Choe
  • Patent number: 6958629
    Abstract: A circuit comprises a signal trace to receive a first large signal, a first plurality of signal traces to receive a small signal pair and a clock trace to receive a clock signal. The circuit further comprises a mixed signal circuit having at least a first and a second element, coupled to the signal trace, the first plurality of signal traces and the clock trace. The mixed signal circuit it to facilitate generation of a second large signal based at least in part on the small signal pair and the first large signal, with the first large signal and the clock signal driving the first and second elements respectively to transition asynchronously.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: October 25, 2005
    Assignee: Intel Corporation
    Inventor: Sapumal Wijeratne
  • Patent number: 6956421
    Abstract: An edge-triggered flip flop includes a clocking portion having first and second transistor stacks that are coupled to first and second storage nodes of a memory element, respectively. In at least one embodiment, a clock signal is applied to an input of at least one transistor in each stack and a delayed and possibly inverted version of the clock signal is applied to an input of at least one other transistor in each stack to clock new data into the memory element.
    Type: Grant
    Filed: July 10, 2003
    Date of Patent: October 18, 2005
    Assignee: Intel Corporation
    Inventor: Mark E. Schuelein
  • Patent number: 6943605
    Abstract: According to some embodiments, scan cell designs are provided for a double-edge-triggered flip-flop.
    Type: Grant
    Filed: December 31, 2002
    Date of Patent: September 13, 2005
    Assignee: Intel Corporation
    Inventors: Paul J. Thadikaran, Nasser A. Kurd
  • Patent number: 6937079
    Abstract: The invention provides a low power, high performance flip-flop. The flip-flop uses only one clocked transistor. The single clocked transistor is shared by the first and second branches of the device. A pulse generator produces a clock pulse to trigger the flip-flop. In one preferred embodiment the device can be made as a static explicit pulsed flip-flop which employs only two clocked transistors.
    Type: Grant
    Filed: July 28, 2003
    Date of Patent: August 30, 2005
    Assignee: University of Louisiana at Lafayette
    Inventors: Peiyi Zhao, Tarek Darwish, Magdy Bayoumi
  • Patent number: 6922094
    Abstract: A data retaining circuit has been disclosed in which, even if a soft error occurs, it is corrected and a normal value can be maintained, the configuration is simple, and high-speed operations are enabled. In this circuit, when a soft error occurs in the data to be put out, it is corrected by a pull-up path or a pull-down path, and when a soft error occurs in the data in the pull-up path or the pull-down path, the error data in the pull-up path or the pull-down path is prevented from affecting each other, as well as turning off the correcting function to prevent the influence on the data to be put out.
    Type: Grant
    Filed: October 28, 2002
    Date of Patent: July 26, 2005
    Assignee: Semiconductor Technology Academic Research Center
    Inventors: Yukio Arima, Takahiro Yamashita, Koichiro Ishibashi
  • Patent number: 6919740
    Abstract: Methods for implementing familiar electronic circuits at nanoscale sizes using molecular-junction-nanowire crossbars, and nanoscale electronic circuits produced by the methods. In one embodiment of the present invention, a 3-state inverter is implemented. In a second embodiment of the present invention, two 3-state inverter circuits are combined to produce a transparent latch. The 3-state inverter circuit and transparent-latch circuit can then be used as a basis for constructing additional circuitry, including master/slave flip-flops, a transparent latch with asynchronous preset, a transparent latch with asynchronous clear, and a master/slave flip-flop with asynchronous preset.
    Type: Grant
    Filed: January 31, 2003
    Date of Patent: July 19, 2005
    Assignee: Hewlett-Packard Development Company, LP.
    Inventor: Greg Snider
  • Patent number: 6911845
    Abstract: A testable, pulse-triggered static flip-flop. A pulse generator produces a data enable trigger pulse only when a test enable input is low, and a scan test enable trigger pulse only when a test enable input is high. The data enable trigger pulse controls the data input to the flip-flop, while the scan test enable trigger pulse controls the scan test input to the flip-flop. The flip-flop consists of a selection circuit comprised of two latches, each including an inverter and a transmission gate. One latch receives the data input and the other latch receives the scan test input. The data enable trigger pulse controls the transmission gate receiving the data input, and the scan test trigger pulse controls the transmission gate receiving the scan test input. The flip-flop also includes a keeper circuit consisting of a feedback inverter and a static latch.
    Type: Grant
    Filed: April 2, 2003
    Date of Patent: June 28, 2005
    Assignee: STMicroelectronics, Inc.
    Inventors: Razak Hossain, Marco Cavalli
  • Patent number: 6864733
    Abstract: A logic circuit includes a data-enable controller for outputting a data value. When implemented as a master-slave flip-flop, a data enable signal controls the activation of a master stage of the flip-flop in conjunction with the transitioning edge of an input clock signal. The data enable signal also controls the feedback of a logical value stored in the slave stage to a storage node of the master stage. Operation of the slave stage may be controlled by the input clock signal only. Through this structural configuration, the flip-flop or latch outputs logical values without requiring any additional forward-path delay elements. As a result, these devices are faster and more efficient than conventional circuits.
    Type: Grant
    Filed: May 29, 2003
    Date of Patent: March 8, 2005
    Assignee: Intel Corporation
    Inventors: Kumar Anshumali, Tom Fletcher
  • Patent number: 6850104
    Abstract: A latch device is provided having a latch mode and a transparent mode. In the latch mode, the latch device synchronizes a data signal to a clock signal. In the transparent mode, the data signal drives the output without clock synchronization, such that the clock input signal is unused. The latch device can be employed in an optical driver for optical network laser diodes.
    Type: Grant
    Filed: March 10, 2003
    Date of Patent: February 1, 2005
    Assignee: Texas Instruments Incorporated
    Inventor: John W. Fattaruso
  • Patent number: 6828837
    Abstract: A flip-flop circuit includes a latch that holds an input signal responsive to an internal clock signal, a comparing circuit that compares the input signal with a latch output to provide a comparison signal, and an internal clock generator that receives an external clock signal and generates an internal clock signal responsive to the comparison signal. The internal clock generating circuit performs a NAND operation on the external clock signal and a delayed inverted version of the external clock signal, to generate the internal clock signal having pulse width smaller than the external clock signal and having rising and falling edges synchronized with the external clock signal. Power consumption is low because the clock buffer and the internal clock generating circuit do not perform switching operations when there is little or no variation in the input signal of the flip-flop.
    Type: Grant
    Filed: September 26, 2003
    Date of Patent: December 7, 2004
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Young-Man Ahn
  • Patent number: 6828838
    Abstract: A logic cell includes a shared clock driver to drive vectored sequential logic elements such as flip-flops and latches with merged outputs. In one embodiment, a logic cell includes a clock signal directly input to the flip-flops, which act as a passgate for latches. The clock signal is also input to a single inverter whose output drives the flip-flops. The outputs of the flip-flops are input into one or more logic gates embedded within the cell. The logic gates generate logical outputs for data signals input to the cell.
    Type: Grant
    Filed: May 30, 2003
    Date of Patent: December 7, 2004
    Assignee: Intel Corporation
    Inventors: Kumar A. Anshumali, Thomas D. Fletcher
  • Patent number: 6822495
    Abstract: An exemplary skew-tolerant true-single-phase-clocking (TSPC) flip-flop is disclosed that reduces current spikes by allowing willful introduction of skew in the clock tree of a single-phase circuit design. More precisely, a split-clock TSPC flip-flop, which allows the flip-flop hold times to be met in the face of skewed clocks, which, in turn, reduces the maximum value of current spikes, can be substituted for a traditional TSPC flip-flop in a sequential logic circuit. The input of the split-clock TSPC flip-flop is latched according to a first clock signal, which was used in a preceding stage, while the output of the split-clock TSPC flip-flop is driven according to a second clock signal. The first and second clock signals can be skewed in time, but have the same frequency and substantially the same phase. Metal Oxide Semiconductor (MOS) device can also be included within the split-clock TSPC flip-flop to reduce power dissipation in cases of large clock skew.
    Type: Grant
    Filed: May 6, 1999
    Date of Patent: November 23, 2004
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Alf Larsson, Lars Svensson
  • Patent number: 6819156
    Abstract: Described are high-speed differential flip-flops. A flip-flop in accordance with one embodiment incorporates some combinational logic, eliminating the need for separate combinational logic when the flip-flop is employed in certain circuit configurations. A flip-flop in accordance with another embodiment includes differential input and output stages, each of which includes a transistor connected across its differential output terminals. The transistors are clocked to short the differential output terminals between expressions of logic levels, thereby limiting the maximum amount of voltage swing required to express subsequent logic levels.
    Type: Grant
    Filed: November 26, 2001
    Date of Patent: November 16, 2004
    Assignee: Xilinx, Inc.
    Inventor: Michael A. Nix
  • Patent number: 6812869
    Abstract: An input/output (I/O) circuit bank is disclosed, in accordance with one embodiment, having programmable I/O circuits configurable to support I/O interface standards for single-ended and differential signaling. The associated pads of one or more of the I/O circuits may be utilized to provide an external reference signal via a pass transistor onto an internal bus for use by the remainder of the I/O circuits. The pass transistors may be designed to function as lowpass filters to limit the amount of noise that passes through them.
    Type: Grant
    Filed: February 13, 2003
    Date of Patent: November 2, 2004
    Assignee: Lattice Semiconductor Corporation
    Inventors: Arifur Rahman, Harold Scholz
  • Patent number: 6753715
    Abstract: A Symmetric Pulse Generator Flip-Flop (SPG-FF). The flip-flop comprises two pulse generator stages that each respond to one particular transition of an input clock signal. Thus, the flip-flop is triggered on both the rising and falling edge of the clock signal to capture an input data signal. The outputs of the generator stages are combined to form a flip-flop output.
    Type: Grant
    Filed: September 20, 2002
    Date of Patent: June 22, 2004
    Assignee: Fujitsu Limited
    Inventors: Volin G. Oklobdzija, William W. Walker, Nikola M. Nedovic
  • Patent number: 6748205
    Abstract: In an integrated circuit, a time-axis expanding circuit is provided in addition to a driver circuit for outputting a signal outside. The time-axis expanding circuit has an equivalent receiver circuit similar to an ordinary receiver circuit, and a D-type flip-flop circuit connected to the equivalent receiver circuit. Input signals from the pins of the time-axis expanding circuit are inputted to the gates of CMOS transistors of the equivalent receiver circuit, and equivalent differential receiving signals outputted from the drains of the CMOS transistors are inputted to the D input terminal of the D-type flip-flop circuit. A measuring clock signal is inputted to the clock input terminal of the D-type flip-flop circuit, and a time-axis-expanded signal is outputted from the Q output terminal of the D-type flip-flop circuit to an output terminal of the time-axis expanding circuit.
    Type: Grant
    Filed: October 31, 2000
    Date of Patent: June 8, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventors: Somei Kawasaki, Masami Iseki
  • Patent number: 6714059
    Abstract: An improved high-speed domino logic circuit uses two delayed clock signals, CLKD and CLKDBAR, and three transistors to introduce a transition delay time. According to the invention, the delayed clock signals are used in conjunction with the three added transistors to avoid the contest or “fight” between a first node and the keeper transistor in the event of a path to ground being created through the logic block portion of improved high-speed domino logic circuit. The improved high-speed domino logic circuits of the invention, in contrast to prior art domino logic circuits, can be designed to have high noise immunity and increased speed. In addition, since according to the invention, only three new transistors are required, the modification of the invention is space efficient and readily incorporated into existing designs.
    Type: Grant
    Filed: January 30, 2003
    Date of Patent: March 30, 2004
    Assignee: Sun Microsystems, Inc.
    Inventor: Swee Yew Choe
  • Patent number: 6693476
    Abstract: A differential latch includes a sample transistor section, a hold transistor section, a 1st gating circuit and a 2nd gating circuit. The sample transistor section is operably coupled to sample, when coupled to a supply voltage (e.g., VDD and VSS) a differential input signal. The hold transistor section is operably coupled to latch, when coupled to the supply voltage, the sampled differential input to produce a latched differential signal. The 1st gating circuit is operable to couple the sampled transistor section to the supply voltage in accordance with a 1st clocking logic operation and a 2nd clocking logic operation. The 2nd gating circuit is operable to couple the hold transistor section to the supply voltage in accordance with a 3rd clocking logic operation and a 4th clocking logic operation.
    Type: Grant
    Filed: July 23, 2002
    Date of Patent: February 17, 2004
    Assignee: Broadcom, Corp.
    Inventor: Tsung-Hsien Lin
  • Publication number: 20040027185
    Abstract: A high-speed differential sampling flip-flop includes a differential data input, a differential offset control input, a sampling clock input, an output, a sampling latch, and an RS latch. The sampling latch includes a sampling latch reset circuit, a current steering circuit, first and second switches, and a regenerative latch. The sampling latch reset circuit is coupled to a first power supply and the current steering circuit. The current steering circuit has first and second control terminals which are coupled to the differential data input. The first switch is coupled between the current steering circuit and a second power supply. The regenerative latch is coupled to the current steering circuit, the second switch, and a third power supply. The sampling latch also includes first and second offset control current sources coupled to the current steering circuit and the second power supply, and having first and second control terminals coupled to the differential offset control input.
    Type: Application
    Filed: August 9, 2002
    Publication date: February 12, 2004
    Inventor: Alan Fiedler
  • Patent number: 6657471
    Abstract: An improved pull-down latch circuit is provided for better latch performance. Previous pull-down latch circuit performance is compromised during pull-up operation since weak PFETs are employed to pull up latch nodes. A pull up assist circuit is incorporated to assist weak PFET when latch node is being pulled up. The assist circuit is isolated from latch circuit when latch node is being pull down to guarantee that pull down circuit can overcome pull-up circuit (for correct latch operation).
    Type: Grant
    Filed: November 8, 2002
    Date of Patent: December 2, 2003
    Assignee: International Business Machines Corporation
    Inventors: Brian W. Curran, Edward T. Malley
  • Publication number: 20030210085
    Abstract: An exemplary skew-tolerant true-single-phase-clocking (TSPC) flip-flop is disclosed that reduces current spikes by allowing willful introduction of skew in the clock tree of a single-phase circuit design. More precisely, a split-clock TSPC flip-flop, which allows the flip-flop hold times to be met in the face of skewed clocks, which, in turn, reduces the maximum value of current spikes, can be substituted for a traditional TSPC flip-flop in a sequential logic circuit. The input of the split-clock TSPC flip-flop is latched according to a first clock signal, which was used in a preceding stage, while the output of the split-clock TSPC flip-flop is driven according to a second clock signal. The first and second clock signals can be skewed in time, but have the same frequency and substantially the same phase. Metal Oxide Semiconductor (MOS) device can also be included within the split-clock TSPC flip-flop to reduce power dissipation in cases of large clock skew.
    Type: Application
    Filed: May 6, 1999
    Publication date: November 13, 2003
    Inventors: ALF LARSSON, LARS SVENSSON
  • Patent number: 6646487
    Abstract: The invention relates generally to the field of electronic circuit design, and in particular to techniques for reducing hazards in a digital logic circuit, for example, a digital logic flip-flop circuit. In an embodiment of the present invention a method for reducing hazards in a flip-flop, including, a pre-charged stage coupled to an evaluation stage by at least an internal node, is provided. First, the pre-charged stage sets the internal node based on a data input. The evaluation stage is prevented from evaluating the internal node for a predetermined time period. After the predetermined time period, the internal node is evaluated by the evaluation stage to determine an output of the flip-flop.
    Type: Grant
    Filed: January 11, 2002
    Date of Patent: November 11, 2003
    Assignee: Fujitsu Limited
    Inventors: Nikola Nedovic, Vojin G. Oklobd{haeck over (z)}ija, William W. Walker
  • Patent number: 6646492
    Abstract: A complementary pass transistor based flip-flop (CP flip-flop) having a relatively small layout area and operable at a high speed with reduced power consumption is provided. The CP flip-flop does not need an additional circuit for retaining latched data in a sleep mode. The CP flip-flop receives a clock signal, delays the clock signal for a predetermined time period, and detects the delay time period from the clock signal. The CP flip-flop receives input data for the predetermined delay time and latches the input data until new input data is received. The CP flip-flop is advantageous in that the design of timing for retaining data can be simplified.
    Type: Grant
    Filed: March 25, 2003
    Date of Patent: November 11, 2003
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Ki-tae Park, Hyo-sik Won
  • Patent number: 6642765
    Abstract: Flip-flop circuitry having an input configured to receive an input signal and an output configured to deliver an output signal corresponding to the input signal; a clock terminal configured to provide timing signals for reception of the input signal at the input and transmission of the output signal at the output; two on-path inverters connected serially between the input and output, and configured not to respond to the timing signals; and two feedback inverters respectively connected in parallel with the two on-path inverters, the first and second feedback inverters being configured to respond to the timing signals.
    Type: Grant
    Filed: December 6, 2001
    Date of Patent: November 4, 2003
    Assignee: Intel Corporation
    Inventors: Dejan Markovic, James W. Tschanz, Vivek K. De
  • Patent number: 6639430
    Abstract: In a latch circuit having a bistable pair of cross connected transistors of a first polarity and a third transistor of a second polarity, a current signal greater than a bias current is received at a latch circuit port, amplified with the third transistor, and applied to the latch circuit port. This decreases the time in which the latch circuit port receiving the current signal greater than the bias current reaches a steady state voltage.
    Type: Grant
    Filed: February 27, 2002
    Date of Patent: October 28, 2003
    Assignee: Broadcom Corporation
    Inventors: Klaas Bult, Rudy Van de Plassche, Jan Mulder
  • Publication number: 20030189451
    Abstract: A flip-flop includes a charge storage area that stores a logic voltage indicating a logic state of the flip-flop, a first transistor having a source or drain connected to a clock signal generating circuit, a second transistor having a source or drain connected to the clock signal generating circuit, a clock signal generated by the clock signal generating circuit that is ramped or sinusoidal, and a latching circuit that latches a latch voltage value based on voltages at the first transistor and the second transistor. The charge storage area supplies a first voltage representing a state of the storage voltage to a gate of the first transistor and supplies a second voltage to a gate of the second transistor.
    Type: Application
    Filed: April 3, 2003
    Publication date: October 9, 2003
    Applicant: THE REGENTS OF THE UNIVERSITY OF MICHIGAN
    Inventors: Conrad H. Ziesler, Marios C. Papaefthymiou
  • Patent number: RE39154
    Abstract: In an integrated circuit, a time-axis expanding circuit is provided in addition to a driver circuit for outputting a signal outside. The time-axis expanding circuit has an equivalent receiver circuit similar to an ordinary receiver circuit, and a D-type flip-flop circuit connected to the equivalent receiver circuit. Input signals from the pins of the time-axis expanding circuit are inputted to the gates of CMOS transistors of the equivalent receiver circuit, and equivalent differential receiving signals outputted from the drains of the CMOS transistors are inputted to the D input terminal of the D-type flip-flop circuit. A measuring clock signal is inputted to the clock input terminal of the D-type flip-flop circuit, and a time-axis-expanded signal is outputted from the Q output terminal of the D-type flip-flop circuit to an output terminal of the time-axis expanding circuit.
    Type: Grant
    Filed: August 19, 2004
    Date of Patent: July 4, 2006
    Assignee: Canon Kabushiki Kaisha
    Inventors: Somei Kawasaki, Masami Iseki