Abstract: A circuit for independently controlling slew and propagation delay of a current DAC is provided. The circuit applies dual slope technique with feed-back control the gate (or control electrode) of a switching transistor to make propagation delay independent control from rise/fall slew rate. This allows one to adjust propagation delay and current slew rate separately to achieve better performance.
Abstract: Adaptive voltage scalers (AVSs), systems, and related methods are disclosed. The AVSs are configured to adaptively adjust voltage levels powering a functional circuit(s) based on target operating frequencies and delay variation conditions to avoid or reduce voltage margin. In one embodiment, the AVS includes an AVS database. The AVS database can be configured to store voltage levels for various operating frequencies of a functional circuit(s) to avoid or reduce voltage margin. The AVS database allows rapid voltage level decisions. The voltage levels stored in the AVS database may be initial, minimum, learned, populated, explored, backed out, temperature-based, and/or age-based voltage levels according to disclosed embodiments to further avoid or reduce voltage margin. An AVS module may be a software-based module that consults the AVS database to make voltage level decisions. Providing the AVS module as a software-based module may allow flexibility in configuring the AVS module and/or the AVS database.
Type:
Application
Filed:
March 30, 2010
Publication date:
April 7, 2011
Applicant:
QUALCOMM Incorporated
Inventors:
Richard A. Moore, Gerald Paul Michalak, Jeffrey T. Bridges
Abstract: A semiconductor integrated circuit comprises: a first signal delay circuit including a first precharge element configured to precharge a first node with a leakage current and a first signal output circuit configured to output a first signal; a second signal delay circuit including a second precharge element configured to precharge a second node with a leakage current and a second signal output circuit configured to output a second signal. The first signal delay circuit is configured to discharge the first node via a first discharge element, while the second signal delay circuit precharges the second node via the second precharge element and outputs the second signal. The second signal delay circuit is configured to discharge the second node via a second discharge element, while the first signal delay circuit precharges the first node via the first precharge element and outputs the first signal.
Abstract: Integrated circuit and programmable delay. One embodiment provides an integrated circuit including a programmable delay element having a plurality of single delay cells. The delay cells include a first input and a second input and a first output. The delay cells are arranged to form a chain such that the first output of a preceding delay cell is coupled to the second input of a successive delay cell. The first inputs of any delay cells are configured to receive an input signal to be delayed. The delay cells out of the plurality of delay cells is configured to constitute a starting point of a signal path including any of the delay cells arranged downstream of the starting point. The first output of the last delay cell in the chain forms an output of the programmable delay element.
Abstract: A bicycle control system is provided with a switch device and a cycle computer. The switch device includes a switch operation member, a sensor arranged relative to the switch operation member to detect operation of the switch operation member, a processing unit operatively coupled to the sensor and a transmitter arranged to transmit an output signal. The processing unit of the switch device includes an identification code generating member, an operating signal generating member and an output member. The identification code generating member generates identification code related to identification of the switch device. The operating signal generating member generates an operation code indicative of operation of the switch operation member. The output member combines the identification code and the operation code as the output signal to be transmitted by the transmitter of the switch device.
Abstract: For differential signal transmission (especially in high speed applications), intra-pair skew between paths carrying complementary portions of a differential signal can significantly affect performance. Conventional de-skew circuits employ simple filters (i.e., low-pass filters) to operate as delay elements to account for skew; however, these filters can distort the differential signal, which can also adverse affect performance. Here, an all-pass, adjustable delay element and de-skew circuit are provided to allow for compensation of skew without degrading the differential signal as conventional circuit do and, thus, having better performance characteristics.
Type:
Grant
Filed:
October 14, 2009
Date of Patent:
February 22, 2011
Assignee:
Texas Instruments Incorporated
Inventors:
Yuxiang Zheng, Hao Liu, Yanli Fan, Mark W. Morgan
Abstract: A clock circuit with delay functions includes a first clock tree and a delay module. The first clock tree provides a first clock signal and includes a first clock root and a plurality of first sub-trees. The delay module is coupled to the first clock root or a designated sub-tree among the plurality of first sub-trees for delaying the first clock signal. The delay module includes at least two delay segments, wherein each delay segment includes a delay and a connection net. The delay time caused by each delay segment is substantially the same.
Abstract: Method, modules and a system formed by connecting the modules for controlling payloads. An activation signal is propagated in the system from one module to the modules connected to it. Upon receiving an activation signal, the module (after a pre-set or random delay) activates a payload associated with it, and transmits the activation signal (after another pre-set or random delay) to one or more modules connected to it. The system is initiated by a master module including a user activated switch producing the activation signal. The activation signal can be propagated in the system in one direction from the master to the last module, or carried bi-directionally allowing two way propagation, using a module which revert the direction of the activation signal propagation direction. A module may be individually powered by an internal power source such as a battery, or connected to an external power source such as AC power.
Abstract: A circuit is provided that includes an input for a clock signal, a random event generator for outputting a random signal, in particular random numbers, a settable delay device that is connected to the input for the clock signal and is connected to the random event generator for the purpose of setting a delay of an edge of the clock signal (clk) by means of the random signal.
Abstract: A regulated delay line device includes main regulator coupled to a node, and a plurality of delay branches coupled to the node to receive a voltage output to the node by the main regulator. Each of the plurality of delay branches includes a micro-regulator and a delay line. The delay line is coupled to the micro-regulator such that unfiltered noise is removed locally at each delay branch by a corresponding micro-regulator.
Type:
Grant
Filed:
February 14, 2008
Date of Patent:
December 28, 2010
Assignee:
International Business Machines Corporation
Inventors:
Daniel Dreps, Daniel Friedman, Seongwon Kim, Hector Saenz, Glen Wiedemeier
Abstract: The timing of output signals can be controlled by coupling a digital signal through a signal distribution tree having a plurality of branches extending from an input node to respective clock inputs of a plurality of latches. A phase interpolator is included in a signal path common to all of the branches, and a respective delay line is included in each of the branches. Each of the latches couples a signal applied to its data input to an output terminal responsive to a transition of the digital signal applied to its clock input. The delay lines are adjusted so that the latches are simultaneously clocked. The delay of the phase interpolator is adjusted so that the signals are coupled to the output terminals of the latches with a predetermined timing relationship relative to signals coupled to output terminals of a second signal distribution tree.
Abstract: A delay chain circuit including at least two delay elements, wherein each delay element is configured to: receive a first signal; output a second signal after a delay period; and be operable in at least two modes of operation wherein in a first mode of operation each delay element has a first delay period and in a second mode of operation each delay element has a second delay period.
Type:
Application
Filed:
December 19, 2008
Publication date:
December 9, 2010
Inventors:
Petri Antero Helio, Jouni Tapio Kinnunen, Niko Juhani Mikkola, Paavo Sakari Vaananen
Abstract: A motor-drive circuit comprising: a current-passage-control circuit to perform ON/OFF control of a drive transistor connected to a motor coil to pass current through the motor coil; an overcurrent-state-detection circuit to detect whether current passing through the drive transistor is in an overcurrent state where the current exceeds a predetermined threshold value; a charging and discharging circuit to start charging a capacitor in response to detecting the overcurrent state by the overcurrent-state-detection circuit and subsequently discharge the capacitor in response to not detecting the overcurrent state; and an overcurrent-protection-control circuit to stop the ON/OFF control to turn off the drive transistor, for an elapsed charging period for a charging voltage of the capacitor at a predetermined voltage to exceed a threshold voltage, and determine whether to perform such an overcurrent-protection-control as to turn off the drive transistor by detection of the overcurrent state, after the charging peri
Type:
Grant
Filed:
November 25, 2008
Date of Patent:
November 30, 2010
Assignees:
Sanyo Electric Co., Ltd., Sanyo Semiconductor Co., Ltd.
Abstract: A delay module, a delay method, a clock detection apparatus, and a digital locked loop (DLL) are disclosed. The delay module includes a first delay unit, a second delay unit and an inverter. Each of the first delay unit and the second delay unit include two logic gates adapted to invert a phase: a logic gate for gating and a logic gate for delaying. These two logic gates are electrically connected. The input port of the logic gate for gating of the first delay unit is electrically connected to the output port of the inverter; the output port of the logic gate for delaying of the first delay unit is electrically connected to the input port of the logic gate for delaying of the second delay unit; the input port of the inverter is electrically connected to the input port of the logic gate for gating of the second delay unit; the input port of the inverter is adapted to input a clock signal to be delayed, and the logic gate for delaying of the second delay unit is adapted to output a delayed clock signal.
Abstract: A current source and a method for designing the current source are provided. The current source is designed by a recursive rule and enables controllable delay lines to provide linear delay and occupy smaller area than conventional controllable delay lines with thermometer code current sources do.
Abstract: A ring oscillator oscillates at a frequency determined by an input bias signal. A bias signal adjusting unit produces a bias signal for the ring oscillator using feedback so that the oscillation frequency of the ring oscillator matches a predetermined reference frequency. An individual bias circuit includes a plurality of bias circuits provided for a total of N second variable delay elements, respectively. The bias circuits are configured such that the bias signals can be individually adjusted.
Abstract: A data receiving circuit has a data input terminal, a conversion circuit converting an input signal received via the data input terminal, and a decision circuit making a decision on an output of the conversion circuit. The conversion circuit has a demultiplexer converting the input signal into a signal of a lower frequency than the frequency thereof at the data input terminal, and an output of the demultiplexer is obtained at the drain side of each of a plurality of first transistors having a common source.
Abstract: A dual rail delay chain having cross-coupled inverters that interconnect the two rails. Delay chain embodiments include cross-coupled inverters that are part of a feed forward signal path between the two rails and are of a larger size than inverters associated with the two rails. The large size feed forward cross-coupled inverters contribute to an enhanced resolution of the delay chain.
Type:
Application
Filed:
April 27, 2009
Publication date:
October 28, 2010
Applicant:
Sun Microsystems, Inc.
Inventors:
Hanh-Phuc Le, Robert P. Masleid, David Greenhill
Abstract: A broad-band active delay line comprises a plurality of broad-band active delay cells configured in a cascade topology. Each broad-band active delay cell comprises a feedback loop and a feedforward path to achieve a high bandwidth.
Abstract: A delay circuit includes first and second selective delay stages each including a number of unit delay cells to delay signals applied thereto; and a delay control unit configured to control selectively applying an input signal to the first selective delay stage or the second selective delay stage in response to a code combination of first and second selection signals and produce an output signal.
Abstract: A clock signal is received at a clock node of a latch module, and a data signal is received at a data node of the latch module. The data signal including information to be latched at a first latch of the latch module and at a second latch of the latch module. A first representation of the data signal to a first data node of the first latch is delayed relative to a second representation of the data signal to a corresponding first data node of the second latch to obtain a first timing requirement between the data signal and the clock signal relative to the first latch that is substantially different than a second timing requirement. An error signal is generated in response to different data being latched at the first latch than at the second latch.
Abstract: An apparatus that is adapted to receive signals from an Inter-Integrated Circuit (I2C) bus is provided. The apparatus comprises a serial data (SDA) filter, a serial clock (SCL) filter, I2C interface logic, and operational circuitry. The SDA filter is adapted to receive an SDA signal from the I2C bus and includes a hold terminal and a disable terminal. The hold terminal of the SDA filter issues a disable signal when a transient in the SDA signal is detected. The SCL filter is adapted to receive an SCL signal from the I2C bus and includes a hold terminal and a disable terminal. The hold terminal of the SCL filter issues a disable signal when a transient in the SCL signal is detected. Additionally, the hold terminal of the SCL filter is coupled to the disable terminal of the SDA filter, and the hold terminal of the SDA filter is coupled to the disable terminal of the SCL filter.
Abstract: A transmission ECU on a transmission side and reception ECUs on a reception side are connected through communication lines and junction connectors. A delay circuit is provided in each of the junction connectors on the side of the reception ECUs. One end of the delay circuit is connected to the communication line on the side of the transmission ECU and the other end of the same is connected to the communication line on the side of the reception ECU. The communication lines on the both ends of the delay circuit are grounded through termination resistors.
Abstract: A method of placing delay units of a pulse delay circuit on a programmable logic device having logic cells in each of cell strings has a step of arranging each delay unit in one logic cell of the device such that the delay units are placed in respective specific cell strings aligned in a row direction and a step of serially connecting the delay units with one another as a straight delay line such that the delay units placed in the specific cell strings in the connecting order are aligned in the row direction. In the device, an inter-string transmission delay time on a line between two logic cells of different cell strings differs from an intra-string transmission delay time on a line between two logic cells of one cell string.
Abstract: Disclosed herein are embodiments of a programmable phase adjusting circuit, a programmable phase adjusting mixer circuit and design structures for these circuits. These circuits comprise a variable delay device connected between input and output nodes. The device includes multiple FETs with input diffusion regions that are connected to a voltage rail via switches so that they can be selectively biased, gates that are connected in series to the input node so that a periodic input signal can be propagated sequentially through each of the gates and output diffusion regions that are connected in parallel to the output node. A current source is connected between the output node and another voltage rail for biasing the output node when the variable delay device is off. The variable delay device enables a circuit in which small increments of selectable phase adjustments can be made to the periodic input signal as a function of propagation delay.
Type:
Grant
Filed:
October 6, 2009
Date of Patent:
September 14, 2010
Assignee:
International Business Machines Corporation
Inventors:
Wagdi W. Abadeer, Anthony R. Bonaccio, Joseph A. Iadanza
Abstract: A stage by stage delay current-summing slew rate controller includes a delay controller, a delay cell array, a current source array, a switch array, a load. The delay cell array includes N delay cells, the switch array includes N switches, and the switch includes N current sources, wherein N>1. The delay controller is connected with the control ports of the delay cells respectively, and the delay cells are connected with the control terminal of the switches respectively. One of the connecting terminals of the switch is connected with the output end of the current source, and the other end of the connecting terminals of the switch is connected with one end of the load, and the other end of the load is connected to the ground.
Abstract: A frame pulse signal latch circuit has: a pulse-width expanding unit which outputs a frame pulse signal FPIN having a pulse width longer than a m-clock cycle; a phase adjustment unit which generates a phase-adjusted output clock CLK?; a flip-flop which latches the frame pulse signal FPIN; a racing detection unit which generates signals, which are shifted by one to m clocks with respect to a frame pulse signal FPOUT, and detects a racing state based on a result of an AND operation of the frame pulse signal FPOUT and the clock-shifted signals; and a control unit which sequentially selects and directs different phase adjustment amounts to the phase adjustment unit, determines an optimal phase adjustment amount based on a worst phase adjustment amount of the case in which the racing state is detected, and gives a direction about the optimal phase adjustment amount to the phase adjustment unit.
Abstract: A method comprises applying a first delay to a first signal that is ahead of a second signal in a series of signals and determining a first number of delay units that provides the first delay to change an order between the delayed first signal and the second signal that has a phase difference with the first signal. The method further comprises determining a similar number for any other pair of signals in the series of signals that have the phase difference. The method further comprises determining a maximum and a minimum from the obtained numbers and determining linearity of the seriels of signals based on a difference between the maximum and the minimum.
Abstract: Disclosed is a timing control circuit that receives a first clock having a period T1, a group of second clocks of L different phases spaced apart from each other at substantially equal intervals and selection signals m, n supplied thereto and generates a fine timing signal delayed from the rising edge of the first clock signal by a delay td of approximately td=m·T1+n·(T2/L). The timing control circuit includes a coarse delay circuit and a fine delay circuit. The coarse delay circuit includes a counter for counting a rising edge of the first clock signal after an activate signal is activated and generates a coarse timing signal whose amount of delay from the first clock signal is approximately m·T1.
Abstract: A delay circuit provides a voltage and temperature compensated delayed output signal. The delay circuit includes a first delay stage that receives an input signal, and generates a delayed output signal from the input signal. The delay circuit also includes a second delay stage that receives the delayed output signal of the first delay stage, and generates a delayed output signal from the output of the first delay stage. The first delay stage and the second delay stage are coupled a voltage supply. The magnitude of the delay of the second delayed signal is inversely proportional to the magnitude of the supply voltage to substantially the same degree that the delayed output signal of the first delay stage is proportional to the magnitude of the supply voltage.
Abstract: A delay cell for delaying an input data signal to generate an output data signal includes a logic circuit and a bias current generator. The logic circuit is used for processing the input data signal to generate the output data signal. The bias current generator is coupled to the logic circuit for providing a first bias current to the logic circuit to control a delay time of the delay cell based on a process corner at which the delay cell is manufactured in a wafer. The bias current generator includes a first transistor coupled between a first power supply and the logic circuit for steering the first bias current of the logic circuit, wherein the first transistor is biased by a first bias voltage.
Abstract: Three flip-flops receive a common data signal input through a data terminal based on different timing signals which are obtained from an external timing signal and differ from one another by a specific delay step. A judging circuit judges whether or not the output data of the three flip-flops coincide with one another. If all the output data coincide with one another, the latch timing is maintained, whereas if the output data of the flip-flop latching the data signal at a fastest or latest timing differs from the output data of the flip-flop latching the data signal at the central timing, the judging circuit changes the variable timing to obtain a suitable latch timing.
Abstract: Embodiments for positioning rising and/or filling edges of data strobe signals are disclosed. One example embodiment may comprise receiving a data signal, positioning an edge of a first delayed data strobe signal associated with the data signal by a first programmable amount, and positioning an edge of a second delayed data strobe signal associated with the data signal by a second programmable amount, wherein the second delayed data strobe signal is shifted approximately one bit-time in relation to the first delayed data strobe signal.
Abstract: One embodiment of the present invention provides a system that biases a floating node within an integrated circuit. During operation, the system first identifies the floating node within the integrated circuit to be biased. The system then determines a desired bias voltage. Next, the system couples a low-power bias source to the floating node to supply the desired bias voltage, wherein the floating node is biased without stopping data transmission through the floating node during biasing.
Abstract: A timing control circuit DLY1 receives clock signal CKa with period T1 and activation signal ACT and outputs fine timing signal FT with delay of m*T1+tda measured from the clock signal where m denotes a non-negative integer and tda denotes delay in the analog delay element. The timing control circuit DLY1 comprises a coarse delay circuit CD and a fine delay circuit FD. The coarse delay circuit CD comprises a counter for counting a rising edge of the clock signal CKa after receiving activation signal ACT and outputs coarse timing signal CT with delay of m*T1 measured from a rising edge of the clock signal CKa. The fine delay circuit FD comprises a plurality of analog delay elements and outputs fine delay timing signal FT with delay of tda measured from the coarse timing signal CT. Variation in delay of timing signal is reduced.
Abstract: Clock driver circuit having upper and lower transistors1 and upper and lower transistors2. Voltage node1 coupled to electrodes of upper transistor1 and upper transistor2. Voltage node2 coupled to electrodes of lower transistor1 and lower transistor2. Coupling transistor1 couples another electrode of upper transistor1 to another electrode of lower transistor2. Coupling transistor2 couples another electrode of upper transistor2 to another electrode of lower transistor1. Two series1 capacitors couple the another electrode of upper transistor1 to the another electrode of lower transistor1. Two series2 capacitors couple the another electrode of upper transistor2 to the another electrode of lower transistor2. Node intermediate the two series2 capacitors provides in-phase clock output. Node intermediate the two series1 capacitors provides anti-phase clock output. In-phase clock input is coupled to control inputs of upper transistor1, coupling transistor1 and lower transistor1.
Abstract: An on-chip logic cell timing characterization circuit is provided. Also provided are a method of conducting setup/hold characterization on a sequential cell and a method of characterizing propagation delay on a logic cell. A sequential cell on which setup/hold time is to be characterized is formed in duplicate with one close to the other. A first clock signal is sampled at a transition of a second clock signal on one sequential cell, and a setup time is determined by a state transition in the output signal of the first sequential. The second clock signal is sampled at a transition of the first clock signal on the other sequential cell, and a hold time is determined by a state transition in the output signal of the second sequential cell.
Abstract: A delay circuit includes a delay time setting circuit to set a delay time of an output signal with respect to an input signal, a first transistor connected to an input terminal of the delay time setting circuit and configured to set a first voltage to the input terminal of the delay time setting circuit and a second transistor connected to an output terminal of the delay time setting circuit and configured to reset the output terminal of the delay time setting circuit to a second voltage and clear the reset of the output terminal of the delay time setting circuit after the first voltage is set.
Abstract: A control signal generation circuit includes a pulse signal generator configured to delay a column control signal by delay times different from each other and to generate first and second pulse signals, a reset signal generator configured to transfer alternatively the first and second pulse signals as a reset signal in response to a write/read flag signal, and a write-enable signal generator configured to generate a write-enable signal from the first pulse signal in response to the write/read flag signal.
Abstract: A ring oscillator based voltage controlled oscillator (VCO) is disclosed. The VCO includes a set of delay cells connected to each other in a ring configuration. Each of the delay cells includes a source-coupled input transistor pair, a current-steering transistor pair and a pair of load resistors. The source-coupled input transistor pair receives a pair of differential voltage inputs. The load resistors, which are connected to the source-coupled input transistor pair, provide a pair of differential voltage outputs. The current-steering transistor pair, which is connected to the source-coupled input transistor pair, receives a pair of differential bias voltage inputs. The output frequency of the VCO is directly proportional to the differential bias voltages at the pair of differential bias voltage inputs.
Type:
Grant
Filed:
November 29, 2007
Date of Patent:
June 15, 2010
Inventors:
Giri N. K. Rangan, Earl E. Swartzlander, Jr.
Abstract: A delay line has a high response speed by minimizing the amount of loading on an input node and an output node while delaying an input signal over a wide variation range. The delay line includes a forward delay unit configured to determine the length of a forward delay path passing an input signal in response to a delay control code, a reverse delay unit configured to receive an output signal of the forward delay unit, and to output a delayed input signal through a reverse delay path that is as long as the length of the forward delay path determined by the delay control code, and a transfer unit configured to transfer the output signal of the forward delay unit from a turn point determined by the delay control code to the reverse delay unit.
Abstract: A delay line appropriate for use in a POR circuit or other integrated circuit in a space environment combines three separate circuit techniques to improve performance without unnecessarily increasing circuit area or adding to manufacturing costs when compared to a simple inverter delay line. The delay line of the present invention uses the selective placement of capacitors throughout the delay line, one-sided current starving, and the incorporation of one-sided Schmitt trigger circuits. Performance of the delay line is substantially immune to SEGR events (“Single Event Gate Rupture”) and SET events (“Single Event Transients”). Spurious signals produced by SEGR and SET events are quickly and substantially attenuated.
Abstract: A delay circuit in a delay locked loop includes a first delay circuit unit for delaying an input signal using a single delay line in response to first control signals and then outputting a first delay signal and a second delay signal, and a second delay circuit unit for delaying the first delay signal and the second delay signal by delay time, which is correspondent to second control signals and third control signals, using a dual delay line and then outputting a third delay signal and a fourth delay signal.
Abstract: Techniques and corresponding circuits for achieving programmable delay of a current mode logic delay buffer are provided. The techniques provide for incremental delay with substantially equal increments Delay may be achieved through the use of a circuit arrangement that allows biasing current to be controlled effect the response time of the circuit by digital control.
Abstract: The present disclosure is an apparatus for generating a decreasing delay with increasing input voltage to a predetermined voltage value at which point the delay may remain constant. The apparatus may include a circuit comprising a voltage regulator receiving an input voltage and two paths of inverters. At least two paths of inverters may be coupled to an input signal, the input signal may be low voltage (e.g. 0) or high voltage (e.g. 1). A first path may be referenced to a reference voltage while the second path may be referenced to the input voltage. The apparatus may include logic gates for receiving the output of each of the first path of inverters and the output of the second path of inverters to generate a desired output. As the input voltage increases, delay of the apparatus may decrease until the input voltage is approximately the same voltage as the reference voltage, at which the delay may remain constant.
Type:
Grant
Filed:
June 13, 2008
Date of Patent:
May 11, 2010
Assignee:
International Business Machines Corporation
Inventors:
Derick G. Behrends, Todd A. Christensen, Travis R. Hebig, Daniel M. Nelson
Abstract: A control signal generation circuit includes a voltage detection unit which detects a level of an external voltage and generates first and second detection signals and a control signal control unit which delays a sense amplifier enable signal in response to the first and second detection signals and generates first through third control signals. The enable period of the first and second control signals are controlled based on the levels of the first and second detection signals.
Abstract: A digital controller for dc-dc switching converters can operate under light load conditions. The controller can be suitable for the use in switch-mode power supplies providing regulated output voltage for handheld devices and other low-power electronics. To create long time intervals, compared to the propagation time of digital logic a DPFM/DPAM can use a ring oscillator with two sets of delay cells and two signals racing around the ring.
Type:
Grant
Filed:
February 20, 2008
Date of Patent:
May 4, 2010
Assignee:
Exar Corporation
Inventors:
Aleksandar Prodić, Kun Wang, Amir Parayandeh
Abstract: A circuit synchronizes parallel data of different timing for transfer. The synchronous data transfer circuit includes a plurality of first flip-flop circuits in which the parallel data are set by a data strobe signal, a plurality of delay circuits, and a plurality of second flip-flop circuits. By configuring the second flip-flop circuits to share generation of a delay amount, the second flip-flop circuits are utilized for data synchronization by the synchronous data transfer circuit. Thus, it becomes possible to configure the delay circuits with a remarkably reduced amount of delay elements.
Abstract: A delay circuit has a fixed delay path at a lower voltage level, a level converter, and an adjustable delay path at a higher voltage level. The fixed delay path includes an inverter chain, and the adjustable delay path includes serially-connected delay elements selectively connected to the circuit output. In an application for a local clock buffer of a static, random-access memory (SRAM), the lower voltage level is that of the local clock buffer, and the higher voltage level is that of the SRAM. These voltages may vary in response to dynamic voltage scaling, requiring re-calibration of the adjustable delay path. The adjustable delay path may be calibrated by progressively increasing the read access time of the SRAM array until a contemporaneous read operation returns the correct output, or by using a replica SRAM path to simulate variations in delay with changes in voltage supply.
Type:
Application
Filed:
October 2, 2008
Publication date:
April 8, 2010
Applicant:
International Business Machines Corporation
Inventors:
Gary D. Carpenter, Jente B. Kuang, Kevin J. Nowka, Liang-Teck Pang
Abstract: A time delay circuit is disclosed and includes a delay line with a first delay circuit and at least a second delay circuit connected downstream. An interpolation circuit is used to generate intermediate signals derived by delayed successive signals in the delay line.
Type:
Grant
Filed:
January 29, 2009
Date of Patent:
March 30, 2010
Assignee:
Infineon Technologies AG
Inventors:
Stephan Henzler, Siegmar Köppe, Dominik Lorenz