Dynamic Bistable Patents (Class 327/200)
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Publication number: 20020024369Abstract: In a flip-flop comprising a control element and a holding element, in which a first current causes the control element to set a logic state and a second current causes the holding element to maintain the logic state, the cut-off frequency is increased by dimensioning the transistors of the holding element HG to be smaller than the transistors of the control element.Type: ApplicationFiled: August 9, 2001Publication date: February 28, 2002Inventor: Reinhard Reimann
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Patent number: 6326815Abstract: A semiconductor integrated circuit includes a sense amplifier for amplifying an input signal and an complementary input signal, a full differential amplifier for amplifying the output of the sense amplifier, and a latch for latching the output of the full differential amplifier and outputting the latched output.Type: GrantFiled: April 12, 2000Date of Patent: December 4, 2001Assignee: Samsung Electronics Co., Ltd.Inventors: Jae-yoon Sim, Hyun-soon Jang, Woo-seop Jeong, Kyung-ho Kim
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Patent number: 6300809Abstract: An apparatus comprising a clock for providing a clock signal, means for providing a delayed version of the clock signal, two transparent latches having clock inputs controlled by opposite polarities of the delayed clock signal, a multiplexer having (i) inputs fed by outputs of the latches, and (ii) a select input fed by the clock signal, and means for providing a select signal for selecting the latch whose clock is inactive. Preferably, each of the latches has a scan input gate and a scan output gate, and the scan output of the first latch is applied to the scan input of the second latch to form a scannable latch pair. Also, preferably, the apparatus further comprises a data port for applying data to the first and second latches, and an exclusive OR gate at the data port, whereby the apparatus produces a gated clock signal. Also disclosed is a method of operating this apparatus.Type: GrantFiled: July 14, 2000Date of Patent: October 9, 2001Assignee: International Business Machines CorporationInventors: Roger Paul Gregor, David James Hathaway, David E. Lackey, Steven Frederick Oakland
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Publication number: 20010019283Abstract: A dynamic latch that can be used in a high-speed analog-to-digital converter is provided. The dynamic latch includes a discharging unit which discharges a first output node in parallel in response to one of a pair of differential input signals and a second output node, and discharges the second output node in parallel in response to the other of the pair of differential input signals and the first output node, and a current source which sinks current from the discharging unit in response to a clock signal. The dynamic latch is capable of removing kick-back voltage which may occur in the existing latch and compensating for a drawback caused by a low-speed charge/discharge, which allows for improvement in operation speed.Type: ApplicationFiled: December 8, 2000Publication date: September 6, 2001Inventors: Gea-ok Cho, Min-kyu Song, Jung-eun Lee
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Patent number: 6278308Abstract: A flip-flop circuit includes a differential stage coupled to a transparent latch. Respective sides of the differential stage, referred to as the “output side” and the “reference side,” are precharged high during a precharge phase. During an evaluation phase, the state of a data input signal is sensed. Depending upon the state of the data input signal, either the output side or the reference side is discharged. Also, during the evaluation phase, the transparent latch is enabled, and thereby samples and stores an output signal from the output side of the differential stage. Upon initiation of the next precharge phase, the transparent latch is quickly disabled (i.e., is placed in an opaque state), and retains its present state. Since only a single side of the differential stage is used to drive the transparent latch, the differential stage may advantageously be implemented in an asymmetric fashion.Type: GrantFiled: October 8, 1999Date of Patent: August 21, 2001Assignee: Advanced Micro Devices, Inc.Inventors: Hamid Partovi, Michael Golden, John Yong
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Patent number: 6275080Abstract: An enhanced single event upset immune CMOS latch circuit is formed of a first and a second cross-coupled invertor having isolation transistors in the path coupling the drains of the transistors in the first invertor.Type: GrantFiled: January 11, 2000Date of Patent: August 14, 2001Assignee: BAE SystemsInventors: Ho G. Phan, Derwin L. Jallice, Bin Li
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Patent number: 6262615Abstract: A dynamic logic circuit having a charging circuit, comprising a first transistor having a first source/drain electrode adapted for coupling to a voltage supply and a second source/drain electrode connected to a node. The charging circuit couples the voltage supply to the node to place an initial charge on the node. A data transfer circuit is provided comprising a second transistor having a gate adapted for coupling to an input strobe pulse, a first source/drain electrode connected to the node, and a second source/drain electrode responsive to an input data and the input strobe pulse, for transferring the input data to the node to the node such that the pre-charged node is either discharged or remains depending on the input data. An output circuit is responsive to an output strobe pulse for coupling the data at the node to an output.Type: GrantFiled: February 25, 1999Date of Patent: July 17, 2001Assignees: Infineon Technologies AG, International Business MachinesInventors: Toshiaki Kirihata, Gerd Frankowsky
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Patent number: 6239638Abstract: A SR flip-flop using a device which has negative resistance between two output electrodes provided on one of two semiconductor regions in a fixed reversible reverse breakdown condition of the semiconductor junction formed between the two semiconductor regions. The SR motion is controlled by applying trigger pulses directly to two output electrodes. In this manner, the circuit is simplified and the operation speed is raised.Type: GrantFiled: April 21, 1999Date of Patent: May 29, 2001Inventor: Tatsuji Masuda
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Patent number: 6222404Abstract: A shut-off circuit included in a dynamic flip-flop isolates output terminals of the dynamic flip-flop from circuitry within the flip-flop that could introduce noise on either output terminal during a portion of the evaluation phase. Since the output terminals are isolated from the input terminals during this portion of the evaluation phase, spurious input signals have no affect on the output signal levels. Similarly, charge within the dynamic flip-flop that is not completely dissipated in the transition from a precharge phase to the evaluation phase has no affect on the output signal levels during this portion of the evaluation phase.Type: GrantFiled: June 28, 1999Date of Patent: April 24, 2001Assignee: Sun Microsystems, Inc.Inventors: Anup S. Mehta, Chaim Amir, Edgardo F. Klass, Ashutosh K. Das
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Patent number: 6191623Abstract: A multi-input comparator determines a minimum or maximum signal value in a given set of signal values. In an illustrative embodiment, a multi-input comparator includes a number of interconnected inversion circuits, with each of the inversion circuits having an input node associated therewith. The input node of each of the inversion circuits is coupled to an output of at least one of the other inversion circuits. As a result, after activation of the inversion circuits, the voltages at the input nodes are indicative of the relative magnitude of the signal values previously applied thereto. The inversion circuits may be constructed using, for example, single-inverter or multiple-inverter building blocks. Additional inputs can be provided by replicating the corresponding single-inverter or multiple-inverter blocks.Type: GrantFiled: September 29, 1998Date of Patent: February 20, 2001Assignee: Lucent Technologies Inc.Inventor: Thaddeus John Gabara
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Patent number: 6163188Abstract: An input buffer and an input-output buffer in full compliance with IDDQ testability are provided, which use a signal fed back to a P-type or N-type controllable switch to turn on or turn off the switch so as to obtain a desired resistance by using an equivalent circuit for the buffer. The problem of reduced operating speed due to the use of a high-impedance resistor is then avoided. Hence, the IDDQ testing results will not be affected by using the input buffer or the input-output buffer, no matter the circuit is operated in an output mode or input mode. Furthermore, the input signal, either in the low state or in the high state, has no effect on the IDDQ testing results either.Type: GrantFiled: October 23, 1998Date of Patent: December 19, 2000Assignee: Faraday Technology Corp.Inventor: Shih-Ming Yu
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Patent number: 6154077Abstract: In a known bitable flip-flop, a first inverter stage (1) is driven by an input signal (D), a second inverter stage (2) by a clock signal (CLK), and a third inverter stage (3) by an output signal (INV2) of the second inverter stage (2). In order to buffer the output signal levels of the inverter stages, the first and third inverter stages (1, 3) can be switched into a disabling state by the clock signal (CLK) and the second inverter stage (2) by an output signal (INV1) of the first inverter stage (1). The new bistable flip-flop is to be set independently of the input signal. For setting the flip-flop, preferably of CMOS design, field-effect transistors (M10, M11) are provided in the third and second inverter stages (3, 2) which inhibit disabling of the third inverter stage (3) by a set signal (SET) and a signal (SETN) that is complementary to it and which allow disabling of the second inverter stage (2) independently of the output signal (INV1) of the first inverter stage (1).Type: GrantFiled: November 9, 1998Date of Patent: November 28, 2000Assignee: TEMIC Semiconductor GmbHInventor: Hans-Peter Waible
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Patent number: 6147546Abstract: A zero volt/zero current fuse arrangement included of two coupled latches is provided, especially for use with interconnect layers made of copper, which prevents the dendritic growth of copper and thus reduces the possibility of "regrowing" the fuse after it has been blown.Type: GrantFiled: March 30, 1998Date of Patent: November 14, 2000Assignee: International Business Machines CorporationInventor: Peter Verwegen
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Patent number: 6147534Abstract: A dynamic set/reset circuit is provided with a first feedback line and a second feedback line. The first feedback line provides an interlocked feedback signal which permits high frequency operation of the set/reset circuit. The second feedback line prevents the interlocked feedback signal from causing the circuit to improperly change state until the next cycle of the circuit. In this manner, the circuit will operate properly despite an unexpectedly wide pulse on an input line. The dual feedback can be used on the set or reset inputs of a set/reset circuit, or both, and the set/reset circuit can be used in various logic and high speed applications, such as within a microprocessor.Type: GrantFiled: June 23, 1999Date of Patent: November 14, 2000Assignee: Sun Microsystems, Inc.Inventors: Song Kim, Hao Chen
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Patent number: 6140855Abstract: A dynamic latch receiver device comprises a sequence of data latch devices arranged in parallel for enabling sequential latching of data signals communicated serially on a single data line. The device includes a first pointer signal generator for generating a sequence of one or more first pointer signals, each generated first pointer signal of a sequence corresponding to a specific latch device and overlapping in time with a prior generated first pointer signal of the sequence; and, a pulse converter device associated with a latch device for receiving a corresponding first pointer signal and generating a respective second pointer signal for input to a respective latch device, each second pointer signal generated in a non-overlapping sequence for triggering a respective latching of each data signal in synchronism with serially communicated data signals.Type: GrantFiled: March 30, 1999Date of Patent: October 31, 2000Assignee: International Business Machines CorporationInventors: Toshiaki Kirihata, Gerhard Mueller, David R. Hanson
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Patent number: 6121807Abstract: A single phase edge-triggered dual-rail dynamic flip-flop circuit for use with dynamic logic gates includes an input stage, precharge stage and buffer. The input stage is coupled to receive a data-input signal and a clock signal. During the precharge phase, the input stage provides an output signal that is the complement of the data input signal. When the data input signal is provided by a dynamic logic gate, the input stage output signal is precharged to a logic high level. During the evaluation phase, the input stage generates an output signal that either remains at a logic high level or else transitions from high-to-low. The precharge stage receives the output signal from the input stage and the clock signal. During the precharge phase, the precharge stage generates a logic high level output signal independently of the signal received from the input stage.Type: GrantFiled: May 24, 1999Date of Patent: September 19, 2000Assignee: Sun Microsystems, Inc.Inventors: Edgardo F. Klass, Chaim Amir
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Patent number: 6084455Abstract: A high-speed CMOS latch includes at each storage node a pull-up P-transistor with its gate tied to a dynamic node, and a pull-down N-transistor with its gate controlled by the inverse of the states of the remaining dynamic nodes. The P-transistor drives the storage node high to VDD, and the N-transistor drives the node low to VSS, as appropriate. During evaluation, one dynamic node discharges to a low state and in response each storage node is driven relatively quickly to the desired high or low state through either the associated pull-up or pull-down transistor. Precharging P-transistors drive the dynamic nodes high during precharge periods. As the dynamic nodes go high, they turn off all of the pull-up and pull-down transistors that drive the latch storage nodes, and the latch retains the evaluated state of the dynamic nodes until the start of the next evaluation cycle. Accordingly, the latch does not require a separate clock.Type: GrantFiled: August 13, 1998Date of Patent: July 4, 2000Assignee: Digital Equipment CorporationInventor: Mark D. Matson
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Patent number: 6069512Abstract: A half latch for latching a voltage at a domino gate output with reduced crossbar current duty cycle, comprising a CMOS inverter with input connected to the domino gate output, a first pMOSFET having a gate and drain connected to ground and having a source coupled to the source of the nMOSFET of the CMOS inverter to prevent the source voltage of the nMOSFET from approaching ground, and a second pMOSFET having a gate connected to the output of the CMOS inverter and having a drain connected to the input of the CMOS inverter.Type: GrantFiled: December 24, 1997Date of Patent: May 30, 2000Assignee: Intel CorporationInventors: Pablo Martin Rodriguez, Kent R. Townley
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Patent number: 6069498Abstract: An apparatus has a clock monitoring device, which determines whether or not the clock rate of an input clock signal (.PHI..sub.0) has fallen below a predetermined minimum clock rate. A system is provided which, from the input clock signal, forms a master clock signal (.PHI..sub.m) and a slave clock signal (.PHI..sub.s) which are in a form such that both the switches (S1) of dynamic master registers (ML) and the switches (S2) of dynamic slave registers (SL) are closed provided that the clock rate has fallen below the minimum clock rate. Otherwise, at most either the switches (S1) of the dynamic master latches (ML) or the switches (S2) of the dynamic slave latches (SL) are closed. The primary advantage achieved hereby is that in the event of failure of the input clock signal, in particular in circuits with a high degree of pipelining, undefined register states do not result in an impermissibly high current consumption.Type: GrantFiled: November 5, 1997Date of Patent: May 30, 2000Assignee: Siemens AktiengesellschaftInventors: Tobias Noll, Stefan Meier, Matthias Schobinger, Erik De Man
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Patent number: 6064245Abstract: The present invention is directed to an apparatus for precharging complementary data circuits. The apparatus comprises two hold circuits, one for storing the data and the other for storing its complement. A signal for initiates precharging the hold circuits to the same signal level, where the signal for initiating the precharging of the hold circuits is dependent on the hold circuits' outputs.Type: GrantFiled: February 19, 1998Date of Patent: May 16, 2000Assignee: International Business Machines CorporationInventors: Rajinder Paul Singh, Pei-Chun Liu, Song Kim
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Patent number: 6052008Abstract: A logic circuit includes an inverter for generating a complement of an output signal from another logic circuit for input to a dynamic logic circuit. The dynamic logic circuit is capable of receiving both the complement signal and dynamic input signals during both the precharge and evaluate phases of the dynamic logic circuit. The complement signal is permitted to switch from both a low level to a high level and a high level to a low level during such stages with the dynamic logic circuit still capable of correctly evaluating the implemented logical operation of the dynamic logic circuit on the complement signal and the dynamic input signals. A p-channel FET is coupled between the internal precharge node and a voltage reference source where the gate electrode of the p-channel FET device receives the complement signal.Type: GrantFiled: July 14, 1997Date of Patent: April 18, 2000Assignee: International Business Machines CorporationInventors: Sam Gat-Shang Chu, Visweswaya Rao Kodali, Michael Ju Hyeok Lee
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Patent number: 6031410Abstract: In a multiplexor, respective outputs of two latches alternately brought into a dynamic holding condition at phases opposite to each other, respectively, are connected in common in a wired connection. Thus, a selector becomes unnecessary, with the result that the number of transistors driven with a clock signal can be reduced, and the electric power consumption is correspondingly reduced.Type: GrantFiled: April 13, 1998Date of Patent: February 29, 2000Assignee: NEC CorporationInventor: Hiroshi Kanno
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Patent number: 6028814Abstract: The present invention is dynamic pulse generator for generating an output pulse from a first input pulse and a second input pulse, where the output pulse is guaranteed to have a pulse width of at least the pulse width of whichever of the two input pulses has a delayed leading edge with respect to the other. The first input pulse has a first leading edge and a first trailing edge. The second input pulse has a second leading edge and a second trailing edge. The second leading edge is delayed from the first leading edge. An edge detector detects the second leading edge, and outputs a first predetermined level when the second leading edge is detected. The edge detector also detects the first trailing edge and the second trailing edge and outputs a second predetermined level. A latch is responsive to the edge detector and generates a signal indicating that the second leading edge has been detected.Type: GrantFiled: January 7, 1998Date of Patent: February 22, 2000Assignee: Integrated Silicon Solution, Inc.Inventor: Steve W. Lim
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Patent number: 5977808Abstract: A latch circuit receives complementary signals and consists of an nMOS transistor whose source is connected to an input terminal of the latch circuit and a series-connected circuit consisting of first and second pMOS transistors arranged between and connected to a drain terminal of the nMOS transistor and a high-potential power supply. The complementary signals are a first signal and a second signal that is an inversion of the first signal. Each of the signals has a pulse characteristic that rising time is longer than falling time. The latch circuit latches a quick fall by passing the first signal through the nMOS transistor. On the other hand, the latch circuit latches a slow rise by turning on the second pMOS transistor in response to a fall in the second signal.Type: GrantFiled: August 12, 1997Date of Patent: November 2, 1999Assignee: Kabushiki Kaisha ToshibaInventors: Naoka Yano, Hiroaki Murakami, Yukinori Muroya
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Patent number: 5973529Abstract: A low-power pulse-to-static conversion latch circuit is disclosed. The circuit includes self-timed control and an n-bit latch array both designed utilizing self-resetting CMOS circuit techniques. The self-timed feature of the control requires only one system clock input. The evaluation, reset and write-enable controls are all generated within a control macro. The latch is level sensitive scan design (LSSD) compatible and complies with self-resetting CMOS (SCRMOS) test modes. Use of these latches facilitates the synchronization, pipelined operation, power-management, and testing of advanced digital systems employing a mix of static and dynamic circuits to achieve high performance.Type: GrantFiled: January 6, 1997Date of Patent: October 26, 1999Assignee: International Business Machines CorporationInventors: Terry Ivan Chappell, Walter Harvey Henkels, Wei Hwang, Rajiv Vasant Joshi
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Patent number: 5973531Abstract: A dynamic pulse register which uses a standard clock signal and exhibits reduced propagation delay. The dynamic pulse register includes a precharge logic block configured to precharge an evaluate signal and an evaluate complement signal during a precharge phase. During an evaluate phase, a pulldown logic block is configured to discharge either the evaluate or evaluate complement signal in response to a valid data input to the pulse register. A driver logic block is configured to convey a data out signal as the complement of the evaluate complement signal, and a data out complement signal as the complement of the evaluate signal. Either the data out signal or the data out complement signal is thus charged (thereby producing the rising edge of the output pulse) in response to the discharging performed by the pulldown logic block.Type: GrantFiled: June 20, 1997Date of Patent: October 26, 1999Assignee: Sun Microsystems, Inc.Inventors: Song C. Kim, Kuan-yu J. Lin
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Patent number: 5959484Abstract: A feedback circuit is provided which is capable of realizing handshake functions, flip flop functions, and other functions using a smaller number of elements and chip surface. The threshold circuit is provided with an electrode which is electrically floating and a plurality of input electrodes which are connected with the floating electrode via capacity elements, and the circuit has a mechanism for essentially determining the potential of the floating electrode by means of the potentials applied to the input electrodes, and the output of the circuit is determined by the potential of the floating gate; the output of the threshold circuit is connected to at least one of the plurality of input electrodes, either directly, or via at least one circuit of some type.Type: GrantFiled: February 27, 1997Date of Patent: September 28, 1999Assignees: Tadashi Shibata, Tadahiro OhmiInventors: Tadahiro Ohmi, Tadashi Shibata, Hiroaki Terada, Koji Kotani
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Patent number: 5952861Abstract: A dynamic pulse register which uses a standard clock signal and exhibits reduced propagation delay. The dynamic pulse register includes a precharge logic block configured to precharge an evaluate signal and an evaluate complement signal during a precharge phase. During an evaluate phase, a pulldown logic block is configured to discharge either the evaluate or evaluate complement signal in response to a valid data input to the pulse register. A driver logic block is configured to convey a data out signal as the complement of the evaluate complement signal, and a data out complement signal as the complement of the evaluate signal. Either the data out signal or the data out complement signal is thus charged (thereby producing the rising edge of the output pulse) in response to the discharging performed by the pulldown logic block.Type: GrantFiled: June 19, 1997Date of Patent: September 14, 1999Assignee: Sun Microsystems, Inc.Inventors: Song C. Kim, Kuan-yu J. Lin
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Patent number: 5952859Abstract: A dynamic set/reset circuit is provided with a first feedback line and a second feedback line. The first feedback line provides an interlocked feedback signal which permits high frequency operation of the set/reset circuit. The second feedback line prevents the interlocked feedback signal from causing the circuit to improperly change state until the next cycle of the circuit. In this manner, the circuit will operate properly despite an unexpectedly wide pulse on an input line. The dual feedback can be used on the set or reset inputs of a set/reset circuit, or both, and the set/reset circuit can be used in various logic and high speed applications, such as within a microprocessor.Type: GrantFiled: March 9, 1998Date of Patent: September 14, 1999Assignee: Sun Microsystems, Inc.Inventors: Song Kim, Hao Chen
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Patent number: 5936449Abstract: A dynamic CMOS register implemented on a silicon die that requires the use of only two input signals, a data-in signal and an inverse clock signal. Each embodiment includes a self-timed clock circuit having a CMOS PNN tier of FETs with a P channel and two N channels connected serially (sources of P channel at one end connected to bus and N channel at the other end connected to ground, and gate of end N channel connected to bus), a first inverter to receive inverse clock with output connected to gate of P channel, a second inverter connected to drain of P channel, and a NOR gate with one input receiving inverse clock, second input connected to output of second inverter and output connected to gate of center N channel. In one embodiment, a single self-timed clock circuit interfaces with and controls a plurality of CMOS registers.Type: GrantFiled: September 8, 1997Date of Patent: August 10, 1999Assignee: Winbond Electronics CorporationInventor: Eddy C. Huang
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Patent number: 5926051Abstract: By setting the substrate potential of a transistor of a driver means lower than the substrate potential of a transistor of a bias means in an intermediate potential generation circuit which supplies a cell plate potential of a memory cell and a precharge potential of a bit line, a flow of a through current in a transistor of the driver means is prevented. Therefore, reduction of a power consumption of the device during standby can be realized.Type: GrantFiled: September 6, 1996Date of Patent: July 20, 1999Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Kiyohiro Furutani
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Patent number: 5920218Abstract: A single phase edge-triggered dual-rail dynamic flip-flop circuit for use with dynamic logic gates includes an input stage, precharge stage and buffer. The input stage is coupled to receive a data-input signal and a clock signal. During the precharge phase, the input stage provides an output signal that is the complement of the data input signal. When the data input signal is provided by a dynamic logic gate, the input stage output signal is precharged to a logic high level. During the evaluation phase, the input stage generates an output signal that either remains at a logic high level or else transitions from high-to-low. The precharge stage receives the output signal from the input stage and the clock signal. During the precharge phase, the precharge stage generates a logic high level output signal independently of the signal received from the input stage.Type: GrantFiled: September 19, 1996Date of Patent: July 6, 1999Assignee: Sun Microsystems, IncInventors: Edgardo F. Klass, Chaim Amir
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Patent number: 5912937Abstract: A flip-flop includes non-volatile storage of a bit for encryption purposes or other applications. The non-volatile bit remains in the flip-flop, substantially unaltered, irrespective of normal flip-flop operation, and is available to be recalled whenever it is needed. The flip-flop is implemented using a pair of CMOS cells. Each cell includes a floating gate formed by connecting the gates of an n-mos transistor and a p-mos transistor. One of the two floating gates is selectively charged by hot electron injection, thereby raising the threshold of that cell. Depending upon which of the two cells is programmed by this process, the flip-flop outputs a logic one or a logic zero during a recall mode.Type: GrantFiled: March 14, 1997Date of Patent: June 15, 1999Assignee: Xilinx, Inc.Inventors: F. Erich Goetting, Scott O. Frake
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Patent number: 5889422Abstract: Power consumption is reduced in a semiconductor integrated circuit. In a conventional flip-flop circuit, there is a transistor between one side current electrode of a PMOS transistor (PTr7) and an node (V0) of a power source. This transistor is deleted and one side current electrode of (PTr7) is connected to an node (D2). In a similar manner, one side current electrode of (PTr13) is connected to an node (D13), one side current electrode of an NMOS transistor (NTr6) is connected to an node (D6), and one side current electrode of (NTr14) is connected to an node (D12). Thus, by deleting transistors, the capacity of transistors which are to be driven by a clock signal is reduced, and therefore, power consumption is reduced.Type: GrantFiled: October 10, 1996Date of Patent: March 30, 1999Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Tatsunori Komoike, Kazuhiro Sakashita
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Patent number: 5867049Abstract: Circuits and methods for a zero setup time storage element are disclosed. A storage element having a data input terminal, a clock input terminal and a data output terminal is able to capture a logic value of a data signal on the data input terminal with a substantially zero setup time at an active edge of a clock signal. Furthermore, some embodiments of the storage element are able to drive the captured logic value until the next active edge. One embodiment of the storage element includes a control circuit coupled to an output driver circuit. Depending on the state of the data input signal during an active edge, the control circuit can drives a first control signal to the output driver circuit or a second control signal to the output driver circuit. The output driver drives a data output signal on the data output terminal of the storage element based on the values of the control signals.Type: GrantFiled: November 21, 1996Date of Patent: February 2, 1999Assignee: Sun Microsystems, Inc.Inventor: Bassam J. Mohd
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Patent number: 5825224Abstract: A dynamic flip-flop includes a first input latch coupled to receive a data input signal and a second input latch coupled to receive the complement of the data put signal. The first and second input latches have first and second shutoff circuits, respectively. During a precharge phase, the first and second input latches each provide an output signal of a first logic level. During an evaluation phase, the first and second input latches sample the data input signal and complemented data input signal, respectively. In response to the samples of true and the complement of the data input signal, one input latch's output signal will transition to a second logic level, while the other input latch's output signal will remain at the first logic level. A first output latch and a second output latch are coupled to receive the output signals of the first and second input latches, respectively. The first and second output latches are inverting.Type: GrantFiled: July 29, 1996Date of Patent: October 20, 1998Assignee: Sun Microsystems, Inc.Inventors: Edgardo F. Klass, David W. Poole, Chaim Amir, Raymond A. Heald
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Patent number: 5815019Abstract: Disclosed herein is a flip/flop circuit of a master-slave type including master side and slave side latch/hold circuits 1 and 2 each being of an ECL vertical 1-step construction, first and second bias circuits 3 and 4 for biasing current sources Tr's 21 to 24 of these latch/hold circuits 1 and 2 and a control circuit 5 for pull-down controlling these first and second bias circuits 3 and 4 by clock signals. The current sources Tr's 21 to 24 are thus selectively rendered conductive and non-conductive to perform a flip-flop operation on a low power source voltage such as 1V or less.Type: GrantFiled: September 23, 1996Date of Patent: September 29, 1998Assignee: NEC CorporationInventors: Gohiko Uemura, Jun Yoshida
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Patent number: 5815008Abstract: Negative-resistance resonant tunnel diodes (RTDs) perform a complete set of logic functions with a single basic configuration. Inputs feed through Schottky diodes to a transfer RTD coupled to a clocked latch having two RTDs in series. Cascaded gates are driven synchronously by multiple clock phases or by asynchronous event signals. An XOR configuration also provides logical inversion.Type: GrantFiled: June 5, 1997Date of Patent: September 29, 1998Assignee: Mayo Foundation for Medical Education and ResearchInventors: William Williamson, III, Barry Kent Gilbert
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Patent number: 5764089Abstract: A high-performance dynamic flip-flop circuit implementation. The dynamic flip-flop circuit comprises an "implicit" one-shot to generate a delayed clock output (319). The flip-flop comprises a delay block (317) coupled to a clock input (305). The flip-flop may be a D-type flip-flop. In a positive-edge-triggered embodiment of the flip-flop, a falling edge (440) of the delayed clock output (319) follows a rising edge (444) of a clock signal after a delay period (448). The flip-flop clocks in new data at a data input (305) in response to the clock input (310) during this delay period (448). Data is held in a storage block (360). The flip-flop has extremely good transient characteristics, especially set-up and clock-to-output times. The flip-flop consumes no static power.Type: GrantFiled: August 30, 1996Date of Patent: June 9, 1998Assignee: Altera CorporationInventors: Hamid Partovi, Robert C. Burd, Udin Salim, Frederick Weber, Luigi Di Gregorio, Donald A. Draper
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Patent number: 5760626Abstract: A data value is passed from a bus (50) to a receiver (40) without a propagation delay. A data latch (10) stores the data value while the data value is being generated by the bus (50). The data latch (10) then holds the data value and provides the data value to the receiver (40) after the data value is no longer present on the bus (50). The data latch (10) has a data storage circuit (11), a diode clamping circuit (12), and a current sourcing circuit (13). The data value is stored by the data storage circuit (11) by a feed-back loop circuit.Type: GrantFiled: April 1, 1996Date of Patent: June 2, 1998Assignee: Motorola Inc.Inventor: Perry H. Pelley, III
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Patent number: 5698997Abstract: Negative-resistance resonant tunnel diodes (RTDs) perform a complete set of logic functions with a single basic configuration. Inputs feed through Schottky diodes to a transfer RTD coupled to a clocked latch having two RTDs in series. Cascaded gates are driven synchronously by multiple clock phases or by asynchronous event signals. An XOR configuration also provides logical inversion.Type: GrantFiled: September 28, 1995Date of Patent: December 16, 1997Assignee: Mayo Foundation for Medical Education and ResearchInventors: William Williamson, III, Barry Kent Gilbert
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Patent number: 5646566Abstract: A dynamic latch circuit design minimizes set and restore power without sacrificing speed. The dynamic latch circuit provides two significant power saving advantages over traditional dynamic latch designs. The first regulates dynamic restore power with the state of the latch. If the dynamic internal node of the latch has not been discharged, then the restore signal applied to the input of the latch is not transferred to the restore device attached to the node. By isolating the restore device under these conditions, additional power is not wasted boot-strapping up the already precharged node. Second, by design, the restore path and set path are separate. The input signals used to set the latch are different and isolated from those performing the restore. Therefore, there is no conducting path between the voltage source and circuit ground as the restore device turns on.Type: GrantFiled: June 21, 1996Date of Patent: July 8, 1997Assignee: International Business Machines CorporationInventors: Robert A. Ross, Jr., Kevin A. Batson
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Patent number: 5631941Abstract: A quantized voltage is held by a holding circuit or a feedback circuit connected to a quantizing circuit so that a multi-valued voltage is registered. In another embodiment, outputs of bi-stable circuits with stopwise thresholds are added with weights introduced by a capacitive coupling.Type: GrantFiled: November 16, 1995Date of Patent: May 20, 1997Assignees: Yozan Inc., Sharp CorporationInventors: Guoliang Shou, Sunao Takatori, Makoto Yamamoto
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Patent number: 5629643Abstract: A latch (40) has a clocked feedback path (46) which performs a static latching function while using less power. The latch includes a feedback device (46) which is selectively decoupled from a feed-forward portion (42, 44) of the latch. In a normal mode of operation when the latch will be clocked often, the feedback device of the latch is not enabled and the latch effectively functions as a dynamic latch. When the latch becomes inactive for an extended period of time, the feedback device is again enabled and the latch is able to store a data value indefinitely.Type: GrantFiled: April 15, 1996Date of Patent: May 13, 1997Assignee: Motorola, Inc.Inventors: Claude Moughanni, Jeffrey E. Maguire
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Patent number: 5596296Abstract: A clock driver circuit comprises a first driver including first and second inverters cascaded between an input terminal and a first output terminal for outputting a non-inverted signal delayed from the clock signal applied to the input terminal by a delay amount corresponding to two stages of inverters. The clock driver circuit also comprises and a second driver including third, fourth and fifth inverters cascaded between the input terminal and a second output terminal and a sixth inverter connected between the input terminal and the second output terminal. With this arrangement, a first signal delayed from the clock signal applied to the input terminal by a first delay amount corresponding to the third, fourth and fifth inverters, is synthesized by a wired-OR at the second output terminal with a second signal delayed from the clock signal applied to the input terminal by a second delay amount corresponding to the sixth inverter.Type: GrantFiled: March 30, 1995Date of Patent: January 21, 1997Assignee: NEC CorporationInventor: Hiroshi Asazawa
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Dynamic logic having power-down mode with periodic clock refresh for a low-power graphics controller
Patent number: 5587672Abstract: A controller chip has dynamic logic which is driven by a suspendable clock. Power is reduced in a standby mode when the clock to the dynamic logic is stopped. However, power is still applied to the dynamic logic in standby mode so that the dynamic logic can be quickly resumed without the delay of re-charging the power-supply capacitances in the dynamic logic. Stopping the clock to dynamic logic can eventually cause loss of data. A more severe problem than data loss is power consumption. When the clock is stopped to dynamic logic, the isolated nodes leak and eventually their voltages change. When their voltages change by more than a transistor threshold voltage then both the p-channel and n-channel transistors in dynamic logic cells can turn on, forming a direct current paths between power and ground. Thus power consumption can increase dramatically in suspend mode. The isolated dynamic nodes of the dynamic logic are instead recharged periodically during suspend mode.Type: GrantFiled: September 25, 1995Date of Patent: December 24, 1996Assignee: NeoMagic Corp.Inventors: Ravi Ranganathan, Deepraj S. Puar -
Patent number: 5576645Abstract: A sample and hold flip-flop that includes a clock buffer circuit responsive to a first clock signal for producing a second clock signal and a third clock signal, wherein the second clock is delayed inverted replica of the first clock and wherein the third clock is a delayed inverted replica of the second clock signal; a CMOS inverter having an input and an output, wherein the output of said CMOS inverter forms the output of the sample and hold flip-flop; a first MOS transistor of a first type having a gate terminal connected to the first clock signal and a drain terminal connected to the input of the CMOS inverter; a second MOS transistor of the first type having a gate terminal connected to the second clock signal and a drain terminal being connected to the source terminal of the first MOS transistor of the first type; a first MOS transistor of a second type having a gate terminal connected to the second clock signal and a drain terminal connected to the input of the CMOS inverter; a second MOS transistor ofType: GrantFiled: June 5, 1995Date of Patent: November 19, 1996Assignee: Hughes Aircraft CompanyInventor: William D. Farwell
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Patent number: 5461649Abstract: An apparatus and method for protecting the state of a state machine from an unstable clock signal. The apparatus of one embodiment includes a state register having an input and a first output which provides an output signal corresponding to the state of the state machine and a set or reset input coupled, through a logic circuit, to the first output. The logic circuit is coupled to receive a signal indicating the unstable state of the clock signal. The logic circuit is coupled to receive a signal indicating the unstable state of the clock signal. The logic circuit feeds back the output from the first output to the set or reset input to maintain the state in the state register while the clock signal is unstable. An embodiment of the method comprises storing a state in a state register, receiving a first signal indicating an unstable state of the clock signal and feeding back the output from the state register to the set or reset input while the first signal indicates the unstable clock exits.Type: GrantFiled: May 9, 1994Date of Patent: October 24, 1995Assignee: Apple Computer Inc.Inventors: Robert L. Bailey, Mary B. Johnson
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Patent number: 5455531Abstract: A flip-flop circuit which has a low power requirement and is capable of high-speed operation has first and second latch circuits having respective clock input terminals connected respectively to inverted- and normal-phase clock input terminals, a pair of differential data input terminals connected respectively to the differential signal input terminals of the first latch circuit, a pair of differential output terminals connected respectively to the differential signal output terminals of the second latch circuit, and a power supply and a current source, each connected to the first and second latch circuits. Each of the first and second latch circuits has first and second current mirror circuits energizable by the power supply, and first through fifth MOS transistors, each of the first and second latch circuits being of a dynamic type.Type: GrantFiled: June 16, 1994Date of Patent: October 3, 1995Assignee: NEC CorporationInventor: Shigeki Morisaki
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Patent number: 5448194Abstract: A storage element is provided in a circuit arrangement for latching one bit. A first MOS transistor (T1) is provided which, when a first control signal (S1) is present, switches an input signal corresponding to the bit to the input of the storage element. The storage element is provided with circuit elements by which an output signal at the output of the storage element is brought to a predetermined potential in dependence on the level of the input signal. The circuit arrangement is particularly suitable for constructing an address latch for DRAMs, particularly of the 16-M generation.Type: GrantFiled: August 17, 1994Date of Patent: September 5, 1995Assignee: Siemens AktiengesellschaftInventor: Heribert Geib