Parallel Clocking Patents (Class 377/80)
  • Patent number: 11437985
    Abstract: A duty cycle correction circuit (DCCC) for a multi-modulus frequency divider, the DCCC comprising: a corrector chain comprising a plurality of flip-flops each configured to receive one of the internal signals; and at least one delay selection logic element, each configured to receive an output signal from different ones of the flip-flops and the output of each delay selection logic element is based on the received output signal and the division factor; the DCCC is configured such that: a first state change in its output signal is defined by a transition to a first logic state of one of the internal signals; and a second state change in its output signal is based on a transition to a second logic state of one of the internal signals after a delay period, wherein the duty cycle of the output signal is based on the delay period.
    Type: Grant
    Filed: October 1, 2021
    Date of Patent: September 6, 2022
    Assignee: NXP USA, Inc.
    Inventors: Mathieu Vallet, Stefano Dal Toso, Mathieu PĂ©rin
  • Patent number: 11404102
    Abstract: A semiconductor device includes a gate signal generator to receive a first clock signal and to generate a first gate signal and a second gate signal based on the first clock signal; a gating clock signal generator to receive a second clock signal and to generate a first gating clock signal, a second gating clock signal and a third gating clock signal based on the first and second gate signals from the gate signal generator and the second clock signal; a data sampler to receive a third clock signal from the gating clock signal generator and to sample an input serial data signal based on the third clock signal; and a deserializer to generate a parallel data signal by deserializing the input serial data signal based on at least one of the first, second, and third gating clock signals from the gating clock signal generator.
    Type: Grant
    Filed: December 9, 2019
    Date of Patent: August 2, 2022
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Soo Min Lee, Ki Hwan Seong
  • Publication number: 20140313174
    Abstract: The purpose of the present invention is to reduce a circuit size of a shift register. A shift register of the present invention includes stages each including a holding circuit (11) and a clock output circuit (12). The clock output circuit (12) includes an output terminal (O) that outputs a signal having a high electric potential or a low electric potential, depending on at least one of outputs (Q) from the holding circuit (11) and on a second clock signal. The holding circuit (11) carries out a reset operation in accordance with a first clock signal supplied to a transistor (N1).
    Type: Application
    Filed: December 10, 2012
    Publication date: October 23, 2014
    Inventors: Yuhichiroh Murakami, Yasushi Sasaki, Takahiro Yamaguchi
  • Patent number: 8553026
    Abstract: A display device includes a plurality of scan lines and a scan driver. The scan driver includes a plurality of stages for transmitting a scan signal having a first voltage to the plurality of scan lines, and each of the stages includes a sequential switching unit, a sequential output unit, a concurrent switching unit, and a concurrent output unit. The concurrent output unit includes a first transistor for transmitting a second control signal to the output terminal according to a first control signal during a concurrent driving period before the scan signal is converted from a first level to a second level according to the second control signal, and a gate voltage of the first transistor is controlled by a voltage that is different from the first voltage according to the first control signal.
    Type: Grant
    Filed: December 1, 2011
    Date of Patent: October 8, 2013
    Assignee: Samsung Display Co., Ltd.
    Inventor: Seong-Il Park
  • Patent number: 8552961
    Abstract: A shift register circuit includes plural shift register stages for providing plural gate signals. Each shift register stage includes a driving unit, an input unit, a driving adjustment unit and a pull-down unit. The driving unit is utilized for outputting a gate signal according to a system clock and a driving control voltage. The input unit is put in use for outputting the driving control voltage according to an input control signal and a first input signal. The driving adjustment unit is employed for adjusting the driving control voltage according to a second input signal and a third input signal. The pull-down unit is used for pulling down the gate signal and the driving control voltage according to a fourth input signal.
    Type: Grant
    Filed: May 13, 2011
    Date of Patent: October 8, 2013
    Assignee: AU Optronics Corp.
    Inventors: Yu-Chung Yang, Yung-Chih Chen
  • Publication number: 20120235020
    Abstract: A gated-clock shift register including a series of clocked flip-flops with preceding outputs connected to subsequent inputs as a horizontal digital shift register. Each flip-flop (or other state holding device) includes a clock buffer between the respective flip-flop's clock, and the global clock. Each clock buffer propagates the clock signal when it determines the associated flip-flop will have a state change during that clock cycle (e.g., via an XOR of the flip-flops input and output signals). In the absence of a state change, that buffer does not propagate the clock signal, essentially only clocking the relevant flip-flops. Further, the clock buffer may be implemented with only NMOS devices (or alternatively, only PMOS devices), which offers power savings over an otherwise required CMOS implementation.
    Type: Application
    Filed: March 16, 2011
    Publication date: September 20, 2012
    Applicant: ANALOG DEVICES, INC.
    Inventor: Steven Decker
  • Publication number: 20110228894
    Abstract: An exemplary shift register circuit includes a shift register, a first switching circuit and a second switching circuit. The shift register has a start pulse signal input terminal and a start pulse signal output terminal. The first switching circuit includes a first input switch unit and a second output switch unit respectively electrically coupled to the start pulse signal input terminal and the start pulse signal output terminal. The second switching circuit includes a second input switch unit and a first output switch unit respectively electrically coupled to the start pulse signal input terminal and the start pulse signal output terminal. Moreover, on-off states of the first input and first output switch units are opposite to on-off states of the second input and second output switch units. Moreover, a gate driving circuit using the above-mentioned shift register and switching circuits also is provided.
    Type: Application
    Filed: August 2, 2010
    Publication date: September 22, 2011
    Applicant: AU OPTRONICS CORP.
    Inventors: Po-Kai WANG, Chun-Hao Huang, Chung-Hung Peng
  • Patent number: 7800575
    Abstract: The present invention provides a display device which includes a drive circuit having a CMOS shift register circuit constituted of a simple CMOS circuit. A drive circuit includes a shift register circuit, and the shift register circuit includes n(n?2) pieces of basic circuits which are connected vertically in multiple stages.
    Type: Grant
    Filed: February 5, 2007
    Date of Patent: September 21, 2010
    Assignee: Hitachi Displays, Ltd.
    Inventors: Takayuki Nakao, Hideo Sato, Masahiro Maki, Toshio Miyazawa
  • Patent number: 7177385
    Abstract: The invention relates to a shift register cell for safely providing a configuration bit having a master latch which can be connected to a serial data input on the shift register cell for the purpose of buffer storing a data bit; a first slave latch which can be connected to the master latch for the purpose of buffer storing the data bit; at least one second slave latch which can be connected to the master latch for the purpose of buffer storing the data bit, and having an evaluation logic unit which outputs the configuration bit on the basis of the data bits which are buffer stored in the master latch and in the slave latches. In addition, the invention provides a shift register for safely providing configuration bits which has a plurality of inventive shift register cells which are connected in series to form a shift register chain.
    Type: Grant
    Filed: December 3, 2004
    Date of Patent: February 13, 2007
    Assignee: Infineon Technologies AG
    Inventors: Georg Georgakos, Siegmar Koeppe, Thomas Niedermeier
  • Patent number: 6988217
    Abstract: A method and mechanism for generating a clock signal with a relatively linear increase or decrease in clock frequency. A first clock signal is generated with a first frequency which is then used to generate a second clock signal with a second frequency. The second frequency is generated by dropping selected pulses of the first clock signal. Particular patterns of bits are stored in a storage element. Bits are then selected and conveyed from the storage element at a frequency determined by the first clock signal. The conveyed bits are used to construct the second clock signal. By selecting the particular pattern of bits selected and conveyed, the frequency of the second clock signal may be determined. Further, by changing the patterns of bits within the registers at selected times, the frequency of the second clock signal may be made to change in a relatively linear manner.
    Type: Grant
    Filed: February 27, 2002
    Date of Patent: January 17, 2006
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Philip E. Madrid, Derrick R. Meyer
  • Patent number: 6961403
    Abstract: A programmable frequency divider circuit with symmetrical output is disclosed. The frequency divider includes a non-symmetrical LFSR based component operated in series with a symmetrical divider component. Both the LFSR and the symmetrical divider may be programmed to provide flexibility. The frequency divider can dynamically adjust the divisor of the LFSR component to overcome limitations in the divide resolution due to the series combination of dividers, providing even and odd divisor values. The divider architecture can also provide higher level functions, including synchronization of multiple divider outputs, dynamic switching of divisor values and generation of multi-phased and spaced outputs. The linear feedback shift register (LFSR) component includes a feedback logic network decomposed into multiple stages to realize a maximum latch-to-latch operational latency of one gate delay regardless of the size of the LFSR.
    Type: Grant
    Filed: May 28, 2004
    Date of Patent: November 1, 2005
    Assignee: International Business Machines Corporation
    Inventors: John S. Austin, Matthew T. Sobel
  • Patent number: 6904116
    Abstract: A shift register includes bidirectional register units, a direction switching section, a register unit selecting section, and a shift clock supply section. The bidirectional register units are cascaded through first input/output terminals for data shifting and perform data shifting operation. The bidirectional register units have second input/output terminals which separately and directly input/output data. The direction switching section switches the shifting directions of the bidirectional register units. The register unit selecting section selects one of the bidirectional register units and inputs/outputs data through the second input/output terminal. The shift clock supply section supplies shift clocks to the bidirectional register units ranging from the bidirectional register unit selected by the register unit selecting section to the last-stage bidirectional register unit.
    Type: Grant
    Filed: February 5, 2003
    Date of Patent: June 7, 2005
    Assignee: NEC Corporation
    Inventor: Mitsuyuki Nakamura
  • Patent number: 6891917
    Abstract: A shift register device includes transistor pass gates and latches connected in series and disposed along a data bit line, each latch connected to a corresponding transistor pass gate. Each transistor pass gate is controlled by a separate control signal input line that a provides a signal to the transistor pass gate connected to it. The signals are provided in a staggered time pattern beginning with a latch disposed last in succession, shifting data from one position to the next succeeding position. Each latch is capable of storing one bit of data. The shift register utilizes less silicon space while reducing the amount of power consumed during operation.
    Type: Grant
    Filed: August 4, 2003
    Date of Patent: May 10, 2005
    Assignee: Atmel Corporation
    Inventors: Johnny Chan, Jeff Ming-Hung Tsai, Philip S. Ng
  • Patent number: 6879313
    Abstract: A shift register circuit includes a plurality of latch circuits connected in series to sequentially transfer a pulse signal ST from one to another, a clock signal line transmitting a clock signal CLK, and a plurality of switching circuits performing electrical connection and disconnection between the clock signal line and the plurality of latch circuits. Upon turning on the shift register, at least one of the switching circuits electrically disconnects at least one of the latch circuits from the clock signal line. During an initialization period immediately after power has been turned on, the frequency of the clock signal CLK is lower than in a normal operation period and gradually increases toward the frequency used in the normal operation period.
    Type: Grant
    Filed: March 10, 2000
    Date of Patent: April 12, 2005
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Yasushi Kubota, Hajime Washio, Shigeto Yoshida, Kazuhiro Maeda, Hiroshi Yoneda
  • Patent number: 6788757
    Abstract: A bi-directional shift-register circuit for outputting data in different sequence. A first shift-register unit includes a first-stage control terminal and a first-stage output terminal outputs a first output signal. A second shift-register unit includes a second-stage input terminal coupled to the first-stage output terminal and a third-stage output terminal, a second-stage control terminal and a second-stage output terminal outputs a second output signal. The second-stage control terminal is selectively coupled to the first-stage output terminal and the third-stage output terminal and disables the second shift-register unit according to the first output signal or a third output signal. A third shift-register unit includes a third-stage control terminal and the third-stage output terminal outputs the third output signal.
    Type: Grant
    Filed: June 5, 2003
    Date of Patent: September 7, 2004
    Assignee: AU Optronics Corp.
    Inventors: Shi-Hsiang Lu, Jian-Shen Yu
  • Patent number: 6778627
    Abstract: A shift-register circuit. The PMOS transistor includes a first gate for receiving an inverted output signal output from a previous stage shift-register unit, a first source for receiving an output signal from the previous stage shift-register unit, and a first drain. The first NMOS transistor includes a second gate coupled to the first drain, a second drain coupled to the clock signal and a second source. The capacitor is coupled between the second gate and the second source. The second NMOS transistor includes a third gate coupled to the first source, a third drain coupled to the second source and a third source coupled to the ground level. The third NMOS transistor includes a fourth gate coupled to an output of a next stage shift-register unit, a fourth drain coupled to a connection point of the second gate and the capacitor and a fourth source coupled to the ground level.
    Type: Grant
    Filed: April 10, 2003
    Date of Patent: August 17, 2004
    Assignee: AU Optronics Corp.
    Inventor: Jian-Shen Yu
  • Patent number: 6654439
    Abstract: An apparatus and method for providing a high speed linear feedback shift register is disclosed. The high speed linear feedback shift register of the present invention comprises multiplexer flip flop circuits. The multiplexer gate on the input of each flip flop circuit is the only gate between each pair of flip flop circuits of the present invention. The linear feedback shift register of the present invention is capable of operating as a counter that does not need to be reset. The linear feedback shift register of the present invention may be used as a clock divider circuit.
    Type: Grant
    Filed: June 4, 2001
    Date of Patent: November 25, 2003
    Assignee: National Semiconductor Corporation
    Inventor: Steve Kommrusch
  • Patent number: 6556647
    Abstract: An apparatus and method is disclosed for providing a phase locked loop clock divider circuit utilizing a high speed linear feedback shift register with a two stage pipeline in its feedback path. A plurality of “pre-load” flip flop (PLFF) circuits and multiplexers are coupled to a plurality of linear feedback shift register (LFSR) flip flop circuits and multiplexers. The PLFF circuits hold pre-calculated initial LFSR sequence values to be loaded into the LFSR flip flop circuits. The load enable signal to the PLFF multiplexers and to the LFSR multiplexers is low for three successive input clock cycles. The present invention is capable of operating at high frequencies due to a shortened timing critical feedback path.
    Type: Grant
    Filed: May 1, 2002
    Date of Patent: April 29, 2003
    Assignee: National Semiconductor Corporation
    Inventor: Karthik Reddy Neravetla
  • Patent number: 6493414
    Abstract: An on-chip parallel/load, serial-shift shift register stores information bits for one or more chip parameters. The bits are represented by fuses that are connected to respective input terminals of the shift register. When the chip is not in test mode (TM), the fuses are electrically connected to respective cells of the shift register, and the output of the shift register is electrically isolated from an output buffer. When the chip is put into test mode, the electrical connections between the fuses and the shift register bits are broken, leaving the fuse information isolated in the shift register. The test mode also connects the output of the shift register to the output buffer and the output of the first shift register bit is seen on the output pin. The rest of the shift register information bits are serially shifted out of the shift register by toggling the CEB pin.
    Type: Grant
    Filed: August 2, 2001
    Date of Patent: December 10, 2002
    Assignee: Nanoamp Solutions, INC
    Inventor: John M. Callahan
  • Patent number: 6490332
    Abstract: A shift register includes a plurality of shift register stages having inputs and outputs coupled to form a chain. Each stage includes enable and disable control inputs, with an output of a selected one of the stages coupled to the enable input of a stage a selected number of stages ahead in the chain and to the disable input of a stage a selected number of stages behind in the chain.
    Type: Grant
    Filed: July 30, 2001
    Date of Patent: December 3, 2002
    Assignee: Cirrus Logic, Inc.
    Inventor: Shyam S Somayajula
  • Patent number: 6424691
    Abstract: An apparatus and method is disclosed for providing a phase locked loop clock divider circuit utilizing a high speed linear feedback shift register. A plurality of pre-load flip flop (PLFF) circuits and multiplexers are coupled to a plurality of linear feedback shift register (LFSR) flip flop units and multiplexers. The PLFF circuits hold two initial LFSR sequence values. A load enable signal to the PLFF multiplexers and LFSR multiplexers is high for two input clock cycles. The present invention is capable of operating at high frequencies due to a shortened critical timing path.
    Type: Grant
    Filed: September 21, 2001
    Date of Patent: July 23, 2002
    Assignee: National Semiconductor Corporation
    Inventors: Karthik R. Neravetla, Steven J. Kommrusch
  • Patent number: 6404839
    Abstract: A clock divider circuit having a fifty per cent duty cycle and multiple integer ratios for dividing an input clock signal. In one embodiment, a clock divider circuit may include a chain of serially-coupled flip-flops. The chain may include at least a first and a second flip-flop, both of which may be triggered by a first edge of an input clock signal. A third flip-flop, coupled to (but not part of) the chain may be configured to be triggered by a second edge of the input clock signal. The third flip-flop may be coupled to an output circuit. In addition to receiving the output signal from the third flip-flop, the output circuit may also receive signals from the chain of serially-coupled flip-flops. The output circuit may drive a second clock signal, which may be produced by dividing the first clock signal based upon the signals it receives. The first clock signal may be divided by an even or an odd integer ratio, or may be divided by an integer ratio (e.g. 2.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: June 11, 2002
    Assignee: Sun Microsystems, Inc.
    Inventors: Wai Fong, Jyh-Ming Jong
  • Patent number: 6384713
    Abstract: In this invention compare circuitry is integrated into a serial shift register which can detect a bit pattern of any length with only the delay of three circuits being added to the shift of the last bit in the bit pattern. The circuitry is connected to operate either is a shift register or as a comparator for an N element bit pattern. Between adjacent registers in the shift register is a MUX used to select compare or shift register operation. An exclusive NOR circuit performs the compare between bits of the serial bit stream and reference bits of the pattern to be protected. An AND circuit accumulates the compare of a particular stage with the compare with the preceding stage. In the last stage the AND circuit provide an accumulated compare result of the preceding number of bit equaling in length the length of the bit pattern for which the compare is being performed.
    Type: Grant
    Filed: April 21, 2000
    Date of Patent: May 7, 2002
    Assignee: Marvell International, Ltd.
    Inventor: Daxiao Yu
  • Patent number: 6301322
    Abstract: A balanced dual-edge triggered bit shifting circuit includes a clock circuit to generate low skew, or edge-aligned, complementary clock signals, and a shift register that shifts a data bit in response to the complementary clock signals. The clock circuit is formed from two clock generators, each of which generates the edge-aligned complementary clock signals by alternatively coupling the input terminals of two buffer circuits to a voltage supply terminal and a ground terminal. Transfer gates coordinate the coupling of the input terminals of the buffer circuits so that the resulting output clock signals generated by each clock generator have clock transitions that are substantially simultaneous. The shift register is formed from at least one shift register stage that receives the edge-aligned complementary clock signals. The shift register stage includes two latching stages, each latching stage having an inverter with an output coupled to a latch circuit.
    Type: Grant
    Filed: April 23, 1999
    Date of Patent: October 9, 2001
    Assignee: Micron Technology, Inc.
    Inventor: Troy A. Manning
  • Patent number: 6105106
    Abstract: A balanced switching circuit comprises a plurality of transfer gates, each transfer gate having an input terminal, an output terminal, and at least one control terminal adapted to receive a control signal. Each transfer gate, which may be comprised of pass transistors such as n- and p-channel metal oxide semiconductor (MOS) transistors, is operable to couple the input terminal to the output terminal in response to the control signal. The plurality of transfer gates are arranged in N rows and N columns with the input and output terminals of the N transfer gates in each row connected in series between a first signal terminal and a second signal terminal. Each transfer gate has its control terminal connected to one of N clock terminals adapted to receive respective clock signals. Each clock terminal is coupled to the control terminal of only one transfer gate in each row and only one transfer gate in each column.
    Type: Grant
    Filed: December 31, 1997
    Date of Patent: August 15, 2000
    Assignee: Micron Technology, Inc.
    Inventor: Troy A. Manning
  • Patent number: 6072849
    Abstract: A programmable n stage shift counter divider circuit includes a plurality of n flip-flops arranged in cascade from a first stage to an nth stage. The data inputs of each of the flip flops are coupled with the output of the next preceding stage through corresponding OR gates. A source of preload signals is coupled with the second inputs of the OR gates; and a combined trap detector and terminal count detector has inputs coupled with the outputs of the last n-1 stages of the shift counter circuit and an output coupled with the source of pre-load signals to operate it.
    Type: Grant
    Filed: August 4, 1998
    Date of Patent: June 6, 2000
    Assignee: VLSI Technology, Inc.
    Inventor: D. C. Sessions
  • Patent number: 6061417
    Abstract: A programmable shift register in which the length (e.g., number of bits), number and location of taps, operating mode (i.e., counting up/down) and number of skip states are configured by programming selected memory cells. The programmable shift register includes a plurality of flip-flops, a programmable interconnect circuit, a next-state control circuit and a mode control circuit. The output terminal of each flip-flop drives a different bus line in the programmable interconnect circuit. Each bus line is programmably connected to a plurality of I/O lines via programmable interconnect points (PIPs). At least two of the second lines are connected to the input terminal of each flip-flop via portions (e.g., multiplexers) of the mode control circuit. Programming the PIPs to link selected flip-flop input and output terminals forms one or more shift registers of a selected length.
    Type: Grant
    Filed: December 3, 1998
    Date of Patent: May 9, 2000
    Assignee: Xilinx, Inc.
    Inventor: Steven H. Kelem
  • Patent number: 5987090
    Abstract: A new class of shift registers that shift the contents of a 2.sup.n bit length register up to 2.sup.n -1 positions in n cycles. Shift registers according to the present invention can be constructed to shift left, shift right, or to shift either left or right. A general implementation of this class of shift registers comprises the following hardware: 2.sup.n D flip-flops or D latches for the data register positions of the shift register; logic for each of the 2.sup.
    Type: Grant
    Filed: February 4, 1998
    Date of Patent: November 16, 1999
    Assignee: Gene M. Amdahl
    Inventor: Gene M. Amdahl
  • Patent number: 5926520
    Abstract: The shift register includes a front stage latch portion for inputting input data when a clock signal is at a first level and latching the input data when the clock signal is at a second level, a rear stage latch portion for inputting data from the front stage latch portion when the clock signal is at the second level and latching the input data when the clock signal is at the first level, an input switch for connecting a data input terminal to the front stage latch portion when a mode switching signal is at a first level, and a feedback switch for connecting the rear stage latch portion to the front stage latch portion when the mode switching signal is at a second level. A latch mode clock signal is provided as the aforementioned clock signal when the mode switching signal is at the first level, and a counter mode clock signal or front stage shift register latch output signal is provided as the aforementioned clock signal when the mode switching signal is at the second level.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: July 20, 1999
    Assignee: Fujitsu Limited
    Inventor: Masaru Yano
  • Patent number: 5864253
    Abstract: Data are transmitted from a control device through an interface cable to a set of driver devices in synchronization with an external clock signal, or a complementary pair of external clock signals. The signal line or lines carrying the external clock signal or signals are terminated at both ends by resistors with resistance values matching the characteristic impedance of the interface cable. Each driver device has a comparator that compares the external clock signal with a regulated reference voltage, or compares the two complementary external clock signals with each other, and thereby generates an internal clock signal. The driver devices receive the data in synchronization with these internal clock signals.
    Type: Grant
    Filed: December 6, 1996
    Date of Patent: January 26, 1999
    Assignee: Oki Data Corporation
    Inventors: Shinichi Katakura, Akira Nagumo
  • Patent number: 5761265
    Abstract: A parallel architecture for implementing a digital sequence generator is provided, which contains taps connected to selected fixed memory cells and the taps of the logic circuitry are switched among the cells. The architecture disclosed and claimed herein generates an identical sequence while consuming substantially less power than a linear feedback shift register implementation. The parallel architecture may also be used to implement a parallel shift register in other applications.
    Type: Grant
    Filed: April 24, 1996
    Date of Patent: June 2, 1998
    Assignee: Board of Regents, The University of Texas System
    Inventor: Menahem Lowy
  • Patent number: 5719626
    Abstract: A solid-state image pickup device includes a plurality of pixels each having a light-receiving element and an amplification element, and a scanning circuit having a shift register constituted by connecting a plurality of circuit stages in tandem and capable of almost simultaneously setting outputs from the plurality of circuit stages in a predetermined logical state upon reception of a predetermined control signal. In the solid-state image pickup device, the outputs from the plurality of circuit stages are set in the predetermined logical state to select the plurality of pixels, and the charges in the light-receiving elements are reset while cutting off the amplification elements of the plurality of pixels selected. With this arrangement, an inrush current upon reset can be decreased.
    Type: Grant
    Filed: December 15, 1995
    Date of Patent: February 17, 1998
    Assignee: Nikon Corporation
    Inventors: Toshikazu Yoneyama, Tadao Isogai
  • Patent number: 5701335
    Abstract: A shift register is clocked by propagating two clock networks in opposite directions: one from input towards the output, the other from the output towards the input. The parasitic delays at the end of these networks are picked to be approximately equal. An extra latch is added to the shift register where the two clock networks meet to prevent a race condition. Both clock networks consist of non-overlapping clocks. Non-overlapping clock generator circuits are used to restore the non-overlap of the clocks when parasitic effects start to cause clock overlap as the clocks are propagated over long distances. An extra latch in the shift register at the non-overlapping clock generators prevents the delay of the non-overlapping clock generator from causing a race condition.
    Type: Grant
    Filed: May 31, 1996
    Date of Patent: December 23, 1997
    Assignee: Hewlett-Packard Co.
    Inventor: Alexander J. Neudeck
  • Patent number: 5670901
    Abstract: An effective signal detection circuit for serial transmission apparatuses using bi-phase code is provided, which effective signal detection circuit facilitates reducing variation of characteristics, current consumption, and dimensions thereof. The effective signal detection circuit comprises a shift register further comprising three D-FFs connected in a series input and parallel output circuit; and a determining circuit further comprising an AND element, an NOR element, and a NOR element. A clock pulse having a frequency twice as high as the bit frequency of a bi-phase coded input signal RX is fed to the clock terminals of the D-FFs. The shift register obtains, based on the clock pulse, a parallel signal bundle Q.sub.1, Q.sub.2, Q.sub.3 corresponding to three consecutive half bits of the input signal RX. The parallel signals Q.sub.1, Q.sub.2, Q.sub.3 are input to the input terminals of the AND element and the NOR element connected in parallel.
    Type: Grant
    Filed: September 13, 1995
    Date of Patent: September 23, 1997
    Assignee: Fuji Electric Co., Ltd.
    Inventor: Yutaka Yoshida
  • Patent number: 5633905
    Abstract: Within an integrated circuit a source of digital data is coupled to a distant destination by a serial data path that is characterized by being either an imperfect and lossy transmission line or as possessing significant high frequency attenuation. A single phase clock accompanies the data over the serial data path. A single phase to three phase clock generator at the destination creates the three phase clock. If the destination is a shift register, then the three phase clock can be used for stage-to-stage clocking within the shift register, as well as for getting data into the input bit of the shift register.
    Type: Grant
    Filed: June 20, 1996
    Date of Patent: May 27, 1997
    Assignee: Hewlett-Packard Company
    Inventor: Richard R. Brown
  • Patent number: 5526390
    Abstract: A decoded counter employing a shift register and a zero-detect circuit has the ability of returning to a correct state within a limited number of clock cycles if an invalid state is accidentally assumed by the counter. One of the flip-flops is provided with synchronous set while all the other flip-flops of the shift register are provided with synchronous reset. The output of the last flip-flop of the register drives a single set-reset line common to all the flip-flops and the pull-up line of the zero-detect circuit is connected to the input of the first flip-flop of the register. Optionally, one of the flip-flops may be provided with asynchronous set and the others with an asynchronous reset, for initializing the counter in a certain state through a single clear-load line.
    Type: Grant
    Filed: June 15, 1994
    Date of Patent: June 11, 1996
    Assignee: SGS-Thomson Microelectronics, S.R.L.
    Inventor: Giona Fucili
  • Patent number: 5426682
    Abstract: A sequential logic circuit includes N state hold circuit where N is an integer. Each of the state hold circuits has a first input terminal, a second input terminal and an output terminal. The state hold circuits are cascaded via the respective first input terminals. The second input terminals of the state hold circuits receive a first clock signal. The first input terminal of one of the state hold circuits in a first stage receives a data signal. The output signal is obtained via the output terminal of one of the state hold circuits in a final stage.
    Type: Grant
    Filed: November 26, 1991
    Date of Patent: June 20, 1995
    Assignee: Fujitsu Limited
    Inventor: Motomu Takatsu
  • Patent number: 5397942
    Abstract: A driver circuit in an integrated circuit includes a flip-flop circuit and a plurality of AND gates. The flip-flop circuit causes an external control signal which is supplied externally to synchronize with a clock signal, and produces an internal control signal. The AND gates control a plurality of outputs based on a data signal in accordance with the internal control signal. Since the internal control signal is synchronized with the clock signal, changes in the outputs from the AND gates are delayed from the timing of the clock signal. Thus, it is possible to prevent the occurrence of malfunction caused by a switching current to flow in transient of changes in the outputs.
    Type: Grant
    Filed: August 24, 1992
    Date of Patent: March 14, 1995
    Assignee: NEC Corporation
    Inventor: Masao Yamada
  • Patent number: 5381455
    Abstract: An interleaved shift register 20 includes a plurality of data storage elements 22a-22d having a common data input signal. Each of the plurality of data storage elements 22a-22d has an enable control input that is connected to one of a plurality of clock signals, each of the plurality of clock signals being incrementally out of phase with one another. Interleaved shift register 20 provides multiple data bits of the data signal to be stored within a single clock period of one of the plurality of clock signals, thus greatly improving the data rate without increasing the storage rate of the plurality of data storage elements 22a-22d.
    Type: Grant
    Filed: April 28, 1993
    Date of Patent: January 10, 1995
    Assignee: Texas Instruments Incorporated
    Inventors: Kevin Ovens, Clive Bittlestone, Bob Helmick
  • Patent number: 5367551
    Abstract: An integrated circuit is provided for reducing scale of flip-flops which can be connected in the form of a shift register by the switching operation, in order to facilitate the test during the manufacture of an integrated circuit (gate array). One selector for switching a clock signal for the flip-flops to either of a system clock signal and a scan clock signal is provided not for each of the sequential circuits, but for each of the clock systems for these sequential circuits. In a case of a gate array, for example, this allows a reduction of three gates for each flip-flop to be realized.
    Type: Grant
    Filed: July 2, 1992
    Date of Patent: November 22, 1994
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kenzo Okumura, Satoru Matumoto
  • Patent number: 5357146
    Abstract: A multiplexer for selecting one of at least two input signals as the output on sensing the change in the state of a select input waits for the clock signal of the active first clock to transition to a predetermined state, disconnects the active first clock from the output of the multiplexer and maintains the output of the multiplexer in the predetermined state while waiting for the clock signal of a second clock to transition to the predetermined state. The second clock is connected as the multiplexer output while the clock signal of the second clock is in the predetermined state. In a preferred embodiment, the predetermined state is a low logic level.
    Type: Grant
    Filed: December 31, 1992
    Date of Patent: October 18, 1994
    Assignee: AT&T Bell Laboratories
    Inventor: Martin E. Heimann
  • Patent number: 5259006
    Abstract: A method is provided for eliminating hold time violations in implementing high-speed logic circuits specified in circuit configuration data includes the steps of providing a synchronizer flip-flop device or latch corresponding to every flip-flop device or latch specified in the circuit configuration data. The synchronizer flip-flop is provided immediately upstream in the data path from its corresponding original user flip-flop device. A predetermined amount of delay is added to the user's original clock and data signals. A synchronizing clock signal generator provides a delayed synchronizer clock for each master clock in the circuit which is provided to each user flip flop.
    Type: Grant
    Filed: August 20, 1991
    Date of Patent: November 2, 1993
    Assignee: Quickturn Systems, Incorporated
    Inventors: Roderick A. Price, Bart C. Thielges
  • Patent number: 5202908
    Abstract: A shift register includes a plurality of alternating shifting and latching sections connected in cascade. The phases of clocks (CLK, CLKB) for driving transmission gates (10, 14) of the shifting sections advance in phase relative to the phases of clocks (CLK, CLKB1) for driving transmission gates (12, 16) of the latching sections. The ON-resistance of the transmission gates (10, 14) of the shifting sections is sufficiently larger than that of the transmission gates (12, 16) of the latching sections, so that even when both of the clocks CLK and CLKB are at H or L levels due to delay imparted by inverters included in a clock generator, data to be latched is always given priority over data to be shifted. Thus, the shift register is free of a race condition which otherwise would be caused by a phase difference between the driving clocks.
    Type: Grant
    Filed: November 25, 1991
    Date of Patent: April 13, 1993
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Akiyoshi Hatada
  • Patent number: 5164970
    Abstract: A cascaded driver circuit has two or more stages connected to a common serial data signal line and a common clock pulse signal line. Each stage has a counter circuit for dividing the frequency of the clock pulse signal and an enable latch circuit for latching an enable signal, received from the preceding stage, in response to the divided clock pulses. A data latching circuit in each stage latches serial data in response to the clock pulse signal, starting when the enable signal is latched and stopping when a first number of bits of serial data have been latched. An enable output circuit in each stage sends an enable signal to the next stage when the data latching circuit has latched a second number of bits, the second number being at least two less than the first number.
    Type: Grant
    Filed: December 14, 1990
    Date of Patent: November 17, 1992
    Assignee: OKI Electric Industry Co., Ltd.
    Inventors: Yasuhiro Shin, Teruyuki Fujii
  • Patent number: 5101203
    Abstract: A substantially simultaneous digital data regeneration and deserialization technique for communication systems and information and data processing systems is disclosed. A digital phase lock logic circuit (DPLL) receives the serial stream of clock and data bits at its input and outputs a plurality of clock signals with different phase. A plurality of latches are coupled to receive a respective one of the clock output signals from the DPLL. Each latch receives the serial stream of clock and data bits through a second input such that the latches are sequentially set by substantially simultaneously received clock and data information at the two inputs and the serial data bits within the stream appear as parallel data bits at the latch outputs. Enhanced versions of this circuit are also described, along with an alternate embodiment which uses an analog phase locked loop circuit.
    Type: Grant
    Filed: June 29, 1990
    Date of Patent: March 31, 1992
    Assignee: International Business Machines Corporation
    Inventors: John E. Gersbach, Ilya I. Novof
  • Patent number: 5025419
    Abstract: An input/output circuit wherein a plurality of data lines are provided with a serial/parallel conversion means common to all, so that the circuit is enabled to consume less power and draw a reduced instantaneous current in its operation and be fabricated in an integrated circuit form.
    Type: Grant
    Filed: March 30, 1989
    Date of Patent: June 18, 1991
    Assignee: Sony Corporation
    Inventor: Yoichi Nishino
  • Patent number: 4837790
    Abstract: An m sequence generator according to this invention has a built-in flipflop circuit, whose input is the output of an exclusive OR gate for adding two m sequence inputs modulo 2 and which outputs a GOLD code synchronized with the rise or the fall of a clock signal and can generate selectively the m sequence or the GOLD code.
    Type: Grant
    Filed: October 16, 1987
    Date of Patent: June 6, 1989
    Assignee: Clarion, Co., Ltd.
    Inventor: Masaaki Harada
  • Patent number: 4775990
    Abstract: A serial-to-parallel converter has a number of memory cells connected in series for successively shifting input data in synchronism with a shift clock. The content of each memory cell is transferred by a latch circuit. The memory cells are provided with input terminals so that they can be set to "1" or "0" simultaneously before the entry of input data. This resetting, or presetting, reduces the number of reversals of the output polarity of the memory cells and hence the power consumed by the circuit can be diminished.
    Type: Grant
    Filed: October 6, 1987
    Date of Patent: October 4, 1988
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Setsufumi Kamuro, Akira Yamaguchi
  • Patent number: 4691122
    Abstract: A CMOS D-type flip-flop circuit stage for avoiding the possibilty of feedthrough includes a non-overlapping clock generator section having a true clock output and a complement clock output. The flip-flop circuit includes a master section formed of a first transfer gate, a first regenerative transistor and a first inverter gate. The flip-flop circuit further includes a slave section formed of a second transfer gate, a second regenerative transistor and a second inverter gate. The clock generator provides a two-phase non-overlapping clock for clocking both the master and slave sections so as to prevent inadvertent racethrough of data input to successive stages.
    Type: Grant
    Filed: March 29, 1985
    Date of Patent: September 1, 1987
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Paul G. Schnizlein, Wen-Tsung F. Tang
  • Patent number: 4679214
    Abstract: A shift register having a simple circuit structure and used, for example, in a dynamic RAM device for a refresh operation. The shift register includes a plurality of circuit stages mutually connected in cascade. Each of the circuit stages includes a first transistor, for a transfer gate, which is turned on and off by a first clock signal and to which is input the output signal of the previous circuit stage. A second transistor is provided whose gate electrode is connected to the output of the first transistor, whose drain or source electrode receives a second clock signal having a different phase from the first clock signal, and whose source or drain electrode outputs an output signal. Each circuit stage also includes a reset circuit for rendering the input portion of the first transistor to a reset condition on the basis of the output signal, thereby sequentially transmitting data through each circuit stage.
    Type: Grant
    Filed: September 10, 1984
    Date of Patent: July 7, 1987
    Assignee: Fujitsu Limited
    Inventor: Yoshihiro Takemae