Abstract: The disclosed embodiments relate to circuits that produce synchronized output signals. More specifically, there is provided a synchronization circuit adapted to receive an input signal, the synchronization circuit comprising a delay monitor adapted to produce a delayed input signal, a counter adapted to determine a difference between the input signal and the delayed input signal and produce a coarse timing signal in response thereto, a circuit adapted to produce a fine timing signal based on the input signal, and a circuit adapted to combine the coarse timing signal and the fine timing signal to produce an output signal.

Abstract: Provided is a self-calibrating time code generator and method for generating an accurate time code (e.g., an accurate IRIG waveform). The self-calibrating time code generator includes a phase-locked loop configured to provide a generated output signal based on a phase difference between an absolute time reference signal and a compensated generated input signal, an IRIG encoder configured to couple a present time value with the generated output signal to form an IRIG waveform, a delay difference indicator configured to provide a time interval value based on a comparison of corresponding pulse edges of the generated output signal and the IRIG waveform, and a numerical delay component configured to delay the generated output signal by the time interval value to form the compensated generated input signal used to time-align the IRIG waveform with the absolute time reference signal to form the accurate IRIG waveform.

Abstract: According to one embodiment, a memory controller is disclosed. The memory controller includes a phase locked loop (PLL) to generate a differential reference clock and a first clocking component coupled to the PLL. The first clocking component includes a first delay locked loop (DLL) to receive the reference clock and to generate transmit and receive delay de-skew clock signals, a first set of phase interpolators to provide data transmit de-skewing and a first set of slave delay lines to provide data receive de-skewing.

Abstract: A master Timestamp Synchronization Circuit (TSC) in a Cable Modem Termination System (CMTS) estimates a master timestamp value for an upcoming time reference. The master TSC sends the master timestamp value asynchronously over an Internet Protocol (IP) network to slave TSCs in other CMTSs. The slave TSC compares a local timestamp value with the master timestamp value when the upcoming time reference occurs. If the local timestamp value does not match the master timestamp value, the slave TSC is resynchronized using the master timestamp value.

Abstract: The present invention provides for a system comprising a level shifter configured to receive a first clock signal from a first power domain, to receive a counter signal, to select one of a plurality of intermediate voltages in response to the received counter signal, and to generate a second clock signal in response to the received first clock signal and the selected intermediate voltage. A counter is coupled to the level shifter and configured to receive a divided clock signal and a comparison result signal, and to generate the counter signal in response to the received divided clock signal and comparison result signal. A divider is coupled to the counter and configured to receive the first clock signal and to generate the divided clock signal in response to the received first clock signal. A filter is coupled to the level shifter and configured to receive the second clock signal and to generate a first comparison signal in response to the received second clock signal.

Abstract: A design structure for a high speed computer processor system includes a high speed interface for a graphics processor. In a preferred embodiment, the high speed interface includes a front side bus (FSB) that interfaces to a similar high speed interface on the graphics processor.

Abstract: One embodiment of the present invention provides a system that facilitates phase-buffering on a bit-by-bit basis using a control queue. The system includes a control queue, wherein a stage in the control queue is configured to accept both a first control signal and a second control signal, wherein the first control signal and the second control signal are mutually exclusive, wherein the first control signal being asserted indicates the value of a corresponding bit is zero, while the second control signal being asserted indicates the value of the corresponding bit is one. A forward-transfer mechanism couples the first control signal or the second control signal from the input of the stage through storage elements to the output of the stage. A reverse transfer mechanism accepts an acknowledgement signal at the output of the stage and transfers the acknowledgement signal through a storage element to the input of the stage.

Abstract: A multi-device system having a daisy chain system bus structure and related method of operation are disclosed. A reference signal having a defined oscillation period is communicated around the daisy chain bus structure. Total signal transmission time around the daisy chain bus structure as well as signal transmission time to each one of a plurality of client devices connected to a host device by the daisy chain bus structure may be readily determined.

Abstract: An object of the present invention is to provide a circuit device in which the power consumption can be reduced without the dedicated signal. A circuit device (1) comprising a D flip-flop (F0) for receiving a pulse of a clock signal (CK) to introduce data thereinto and output said introduced data and a shift register (2), comprising the D flip-flops (F1 to F7) for introducing the data thereinto in accordance with the pulse to output the introduced data, for processing the outputted data from the D flip-flop (F0), wherein the circuit device (1) comprises a control circuit (3) for controlling whether the D flip-flops (F1 to F7) are supplied with the pulse of the clock signal (CK) on the basis of outputted data from the D flip-flop (F0) in accordance with the pulse of the clock signal (CK) and data to be introduced into the D flip-flop (F0) in accordance with the next pulse.

Abstract: An improved technique and associated apparatus for timing calibration of a logic device is provided. A calibration test pattern is transferred to a logic device first at a data rate slower than normal operating speed to ensure correct capture of the pattern at the device to be calibrated. Once the pattern is correctly captured and stored, the test pattern is transmitted to the logic device at the normal operating data rate to perform timing calibration. The improved technique and apparatus permits the use of any pattern of bits as a calibration test pattern, programmable by the user or using easily-interchangeable hardware.

Abstract: A clock skew adjustment arrangement for a chip is provided which chip is subdivided in at least two blocks, wherein the blocks are supplied with a clock signal of a single joint clock signal generator via clock signals paths, and wherein to each block a circuitry is assigned for measuring and adjusting the respective clock signal.

Abstract: Broadly speaking, an apparatus and associated method of operation is provided for controlling alignment signal transmission in an electronic communication process. More specifically, a programmable control is provided for controlling transmission of alignment signals in either a Serial Attached SCSI (SAS) or Serial ATA (SATA) communication process. The programmable control includes a counter operated to sequentially modify a count value. When the count value is equal to a programmed alignment trigger value, the programmable control is configured to generate and transmit an alignment signal through the initiator transceiver to the target transceiver. Thus, the apparatus and associated method of operation controls a rate at which alignment signals are transmitted in a SAS/SATA communication process.

Abstract: A method, apparatus and computer instructions for application based tracing and for normalization of processor clocks in a symmetric multiprocessor environment. By deliberately establishing a large skew among processor clocks, it is possible to perform application based tracing by directly using the processors. In addition, the identity, time stamp, and drift information of each processor may be used to create a time library. The time library is used to adjust a measured time to execute a program or software routine. The adjusted time is a normalized time that is statistically more accurate than the measured time alone. The adjusted time is then reported as the time to execute the program or software routine.

Abstract: A technique is described for simultaneously and synchronously transmitting digital data and a clock signal in a digital integrated circuit, circuit board, or system. The technique is based on the phase shift keying (PSK) modulation of an RF high frequency carrier which is distributed on low impedance interconnection transmission lines. The PSK modulation contains the digital data while the carrier itself constitutes the clock signal, and the clock signal and digital data are transmitted in a synchronous manner. The carrier frequency may be near fT, the maximum operation frequency of the transistors. Since the digital data and clock signal are simultaneously transmitted on the same interconnection, the digital data never becomes skewed with respect to the clock signal, or vice versa.

Abstract: A system on a chip includes a processing module, ROM, RAM, and a clocking circuit. The clock circuit is coupled to produce a first clock signal when the SOC is in a low power mode and to produce a second clock signal when the SOC is in a performance mode, where the first clock signal is less accurate than the second clock signal. The clock circuit consumes more power when producing the second clock signal than when producing the first clock signal.

Abstract: Precise timing control across multiple standardized chassis such as PXI is obtained by providing several control signals over PXI_LOCAL within each chassis, and by providing these control signals to other chassis. A Least Common Multiple (LCM) signal enables all clocks to have coincident clock edges occurring at every LCM edge. A start sequence allows all PXI expansion cards in the test system to start at the same time. A MATCH line enables pincard modules to check for expected DUT outputs and either continue execution of their local test programs or loop back and repeat a section of the local test program in accordance with the result of the DUT output check. An End Of Test (EOT) line enables any one pincard module to abruptly end the local test programs running in all other pincard modules if an error is detected by the local test program in the pincard module.

Abstract: The invention provides for the arrangement and management of timing of various domains on a large integrated circuit which introduces a phase offset between clock domains of neighboring cells to create a wavefront clock which propagates through the circuit at the same speed data propagates though the circuit. The cells of the integrated circuit are wavefront clock synchronized in that the phase offset introduced in a particular cell's clock is such that the arrival of a skewed clock and propagation delayed data from that cell's neighbor is synchronized with that particular cell's own clock. Wavefront clock synchronization mitigates at least some of the problems of clock skew and the associated effects of slowing data propagation and reduction of clock frequencies associated with large surface integrated circuits utilizing synchronized clock domains.

Abstract: A predictive time base generator having predictive synchronizer and replica delay element coupled with the synchronizer feedback delay loop. The predictive time base generator receives a clock signal delayed by a predetermined clock delay and produces a predictive time signal advanced in time by an amount represented by the replica delay element. The replica delay element can replicate one or both of a predetermined clock delay and a predetermined data delay, substantially nullifying the respective delays in critical signal paths of a device. The replica delay element can include replicas of structure(s) found in an incoming clock path and an outgoing data path, such elements including, for example, voltage level shifters, buffers or data latches, multiplexers, wire element models, and the like. A predictive computer bus interface adapter which incorporates the aforementioned predictive time base generator also is provided.

Abstract: An electronic device having first circuitry operating in a first clock environment and second circuitry operating in a second clock environment, the first circuitry being arranged to generate a soft reset signal for resetting the second circuitry, the integrated circuit further including: a soft reset hold circuit clocked in the first clock environment connected to receive the soft reset signal and to generate an output reset signal in an asserted state; and a synchronizer clocked in the second clock environment connected to receive the output reset signal and to generate a retimed reset signal in an asserted state after a predetermined period, wherein the retimed reset signal is fed back to the soft reset hold circuit to cause the output reset signal to adopt a deasserted state at the end of said predetermined period.

Abstract: The present invention relates to a method for synchronizing a number of digital clocks to a synchronizing signal, said method comprising generating centrally a reference clock, synthesizing said digital clocks from said reference clock using a clock multiplier, respectively, resetting said clock multiplier in response to said synchronizing signal, and masking an output signal of said clock multiplier during settling time of said clock multiplier.

Abstract: A system, method and computer program product for steering a time-of-day (TOD) clock for a computer system having a physical clock providing a time base for executing operations that is stepped to a common oscillator. The method includes computing a TOD-clock offset value (d) to be added to a physical-clock value (Tr) value to obtain a logical TOD-clock value (Tb), where the logical TOD-clock value is adjustable without adjusting a stepping rate of the oscillator.

Abstract: A memory system and method according to various aspects of the present invention comprises a memory and an adaptive timing system for controlling access to the memory. The adaptive timing system captures data in a data valid window (DVW) in a data signal. In one embodiment, the adaptive timing system comprises a delay circuit for sampling the data signal at a midpoint of the DVW. The adaptive timing system may also comprise an identifying circuit for identifying whether the midpoint of the DVW corresponds to an actual midpoint of the DVW and adjusting the delay circuit accordingly.

Abstract: The present invention provides a method and apparatus for updating serial devices. The apparatus includes a plurality of serial registers. The apparatus further includes a device adapted to provide a signal and a plurality of parallel registers, wherein each of the parallel registers is adapted to access at least one of the plurality of serial registers at substantially the same time in response to detecting the signal.

Abstract: A programmable clock deskewer generates an output clock with minimal clock skew. This is accomplished by means of a single series path coupling the input clock to the output clock. The programmable clock deskewer includes: an output clock generator, responsive to the input clock and control information, to generate the deskewed output clock; and a controller, responsive to the input clock, to generate the control information for controlling the frequency of the deskewed output clock. The programmable clock deskewer may be used to implement a clock tree with various clock outputs for a system on chip integrated circuit.

Abstract: A circuit for data/clock deskewing includes a data delay circuit and a clock circuit. The data delay circuit is arranged to select a delay for the data signal responsive to a data delay signal. The clock circuit is arranged to provide an even clock signal and an odd clock signal, and to select one of them responsive to a clock select signal. Also, two delayed versions of the selected clock signal are provided. The data latching circuit is arranged to latch the delayed data signal with the selected clock and with the two delayed versions of the selected clock signal. Further, the latched data signals are employed to deskew the clock and data signals such that set-up and hold times are substantially optimized under jittery conditions.

Abstract: The present invention provides for a circuit for transitioning clocking speeds. A counter is coupled to the clocking means. A comparator is coupled to an output of the counter. A first divider is coupled to the output of the counter. A processor means is coupled to the output of the first divider, thereby lessening current surges.

Abstract: In some embodiments an apparatus and method may comprise a plurality of lanes between two clock domains, each lane comprising circuitry to generate a first signal when the lane may lose cycle coherency with other of the plurality of lanes, generate a second signal to signify a lane has been delayed, and a control circuit coupled with the plurality of lanes to add latency only to lanes that did not generate a second signal if the control circuit detects a first signal from any of the plurality of lanes.

Abstract: A method and apparatus for providing clock phase alignment in a transceiver system are disclosed. Circuits are provided for providing clock phase alignment to adjust and align the phase between clock domain boundaries and for maintaining alignment of multiple outputs signals.

Abstract: A circuit and a method for aligning transmitted data by adjusting transmission timing for a plurality of lanes. The method includes utilizing different initial values to reset a count value corresponding to a lane when a plurality of COM symbols are detected on the lane, utilizing an increment value to increase the count value corresponding to the lane when a COM symbol is not detected on the lane, and utilizing a plurality of count values corresponding to the lanes to align transmitted data of the lanes when a COM symbol is not detected on the lanes within a predetermined period of time.

Abstract: A clock detection and selection circuit (100) can include a first counter (102-0) that generates a first count value CNT1 according to a first clock signal CLK1 and a second counter (102-1) that generates a second count value CNT2 according to a second clock signal CLK2. First separation-detect logic (102-0) and second separation-detect logic (102-1) determine if a pre-specified difference exists between a first count value (CNT1/CNT1?) and second count value (CNT2/CNT2?). According to such determinations, separation information (INF—1 and INF—2) can be generated indicating which clock signal (CLK1 or CLK2) is faster. Selection logic (106) can select a faster of the clock signals (CLK1 or CLK2) if the separation information values confirm one another.

Abstract: A register-based de-skew system and method for a source synchronous receiver circuit domain. In one embodiment, a de-skew strobe generator operates responsive to at least one incoming strobe signal in order to generate a plurality of one-hot de-skew strobe signals. A plurality of de-skew registers receive the same input data pulses from a transmitter circuit domain. By clocking the de-skew registers with the one-hot de-skew strobe signals, the input data pulses are stretched into spread data pulses having an extended timing window. A plurality of multiplexers multiplex the spread data pulses, whereupon the multiplexed data is registered using a clock signal associated with the receiver circuit domain.

Abstract: A multiprocessor computer system comprises multiple data processors, each with an internal clock for providing time stamps to application software. The processors take turns as synchronization masters. The present master transmits a “request” time stamp (indicating the time of transmission according to the local clock) to the other (“slave”) processors. Each slave processor responds by returning a “response” time stamp (indicating the time of transmission of the response according to the local slave clock) of its own along with the received request time stamp. The master calculates clock adjustment values from the time of receipt of the responses and the included time stamps. This allows asynchronous clocks to be synchronized so that application time stamps can be validly compared across processors.

Abstract: A domain crossing device for use in a semiconductor memory device, including: a unit for comparing a phase of an internal clock signal with a phase of a delay locked loop (DLL) clock signal to generate a first clock selection signal and a phase detection period signal in response to a detection starting signal and a second clock selection signal; a unit for generating a plurality of initial latency signals in response to the phase detection period signal, the detection starting signal and a column address strobe (CAS) latency signal; a unit for receiving the plurality of initial latency signals and the detection starting signal to generate a plurality of latency signals, a clock selection signal and the second clock selection signal; and a unit for generating the detection starting signal based on a self refresh signal, a power-up signal and a DLL disable signal.

Abstract: A drift-tolerant sync generation circuit and sync generation method for a sync pulse generator operable in a clock synchronizer that effectuates data transfer between first circuitry disposed in a first clock domain and second circuitry disposed in a second clock domain. The first clock domain is operable with a first clock signal and the second clock domain is operable with a second clock signal. A sync circuit portion, responsive to a valid edge signal indicative of coincident edges between the first and second clock signals, is operable to generate based upon the ratio a start sync signal substantially centered around the coincident edges. A first sync generator, responsive to the start sync signal, is operable to generate synchronization pulses in the first clock domain. A second sync generator, responsive to the start sync signal, is operable to generate synchronization pulses in the second clock domain.

Abstract: An elapsed cycle number during the predetermined period of the inputted clock source is counted using the clock reference signal as a yardstick, a frequency of the clock source is computed based on an elapsed cycle number obtained by counting, control timing of various interfaces relating to the CPU is adjusted and an interruption generating interval in which interruption is generated regularly by the CPU so that adjustment of control timing of various interfaces and setting of a timer interruption interval during the OS operation in accordance with a frequency of the clock source without performing OS modification such as rebuilding and the like.

Abstract: The invention relates to a method for controlling the reading-in of a data signal at an input of an electrical circuit to an input latch with the aid of a clock signal, with the data item, which is indicated by the data signal, being transferred to the input latch with a clock edge of the clock signal, with the clock edge of the clock signal being shifted in time as a function of a time delay between a signal edge of the input signal at the input and the clock edge, such that the time delay between the signal edge of the data signal and the clock edge is within a predetermined time window.

Abstract: The invention includes a method to adjust integrated circuit device I/O bus timing. In one embodiment, the method includes comparing an alignment between an edge of a first clock signal to a center of a data packet to produce an alignment offset signal and adjusting the first clock signal using a variable delay device in response to the alignment offset signal to substantially align the edge of the first clock signal to the center of the data packet. Other embodiments are claimed and described.

Abstract: A clock switching circuit comprises: a composite clock generation circuit, which is to receive a first clock, a second clock, and a clock switching execution signal for switching between the first clock and the second clock, and to make a level of the clock fixed to be a second level and to output the clock as a composite clock for clock switching, for a specified period including one of a leading edge and a trailing edge of the clock as well as additional time before and after the edge, when the signal becomes active while the clock is at a first level; a switching demand signal generation circuit that receives the clock and the signal, and outputs a clock switching demand signal; a clock selection signal generation circuit that changes a level of a first clock selection signal when the signal becomes active; and a first selector that selects one of the clock and the clock, according to the level of the signal, and outputs the selected clock.

Abstract: According to one embodiment a computer system is disclosed. The computer system includes a bus and a chipset coupled to the bus. The chipset detects the slew rate of a signal transmitted over the bus by the chipset. In addition the chipset adjusts the slew rate based upon the state of the signal.

Abstract: An apparatus and method for processing a captured image and, more particularly, for processing a captured image comprising a document. In one embodiment, an apparatus comprising a camera to capture documents is described. In another embodiment, a method for processing a captured image that includes a document comprises the steps of distinguishing an imaged document from its background, adjusting the captured image to reduce distortions created from use of a camera and properly orienting the document is described.

Abstract: Methods and apparatus for testing a semiconductor device. A testing interface is configured to interface with an external test apparatus and a device under test (DUT). In one embodiment, the testing interface receives test data and a test clock signal from the external test apparatus. The test data is clocked out of the testing interface and to the DUT according to the test clock signal. Further, the test clock signal is delayed by a period of time and then a delayed clock signal is issued to the device. The data previously written to the DUT is read out of the DUT and compared with the test data received from the external test apparatus. The period of time by which the test clock signal is delayed can be varied to achieve a desired timing.

Abstract: A technique for promoting determinism among bus agents within a point-to-point (PtP) network. More particularly, embodiments of the invention relate to techniques to compensate for link latency, data skew, and clock shift within a PtP network of common system interface (CSI) bus agents.

Abstract: A method for selectively deskewing data traveling through a bus in a network device is disclosed. Bit-level data is received from each data line of a plurality of data lines of the bus. Vertical line information is detected for the plurality of data lines to determine if there is a match with a training pattern. A skew distance is calculated once there is a match with the training pattern. Then, the plurality of data lines are bit aligned based on the skew distance.

Abstract: A data processing system may comprise an initiator device having an output whose timing is referenced by a clock input alone corresponding to a first delay along a signaling path. The exemplary data processing system further may further comprise a target device having an input whose timing is referenced by a clock input alone corresponding to a second delay along the signaling path and a system bus interconnected between the initiator device and the target device within the signaling path. The exemplary data processing system may further comprise a dynamic timing bridge coupled to the system bus within the signaling path, wherein responsive to a control signal representative of at least one system characteristic, the dynamic timing bridge performs one selected from the group consisting of (i) inserting a cyclic latency within the signaling path and (ii) not inserting the cyclic latency within the signaling path.

Abstract: Methods and apparatus to provide a clustered variations-aware architecture are described. In one embodiment, one or more variations within a clock domain are detected and utilized to adjust a clock signal of the clock domain.

Abstract: A method to obtain configuration data for a data processing apparatus by calculating (110) a time interval between the commencement of a mode (104) and a subsequent event (108). The calculated time interval is then compared (112) with one or more reference values (114). The result of the comparison is used to derive configuration data (116). The method may be further refined by including a calibration stage to reduce the error in the calculated time interval, thereby allowing comparison with a larger set of reference values (114), which in turn permits more configuration data to be derived from the calculated time interval.

Abstract: A synchronous signal generator is provided that contains a first and second counting and delay circuit, which both are in a subhierarchical position with respect to a reset signal synchronization/delay circuit. The reset signal synchronization/delay circuit and the first and second counting and delay circuit are triggered by a basic clock signal or a first clock signal derived therefrom to be identical in frequency and phase, and contain counting means whose initial and final counting state are adjustable in order to set, in a clocked fashion, the temporal positions of a first and second load signal that are output by the first counting and delay circuit as well as of a FIFO read clock signal that is output by the second counting and delay circuit and thus adapt them to the temporal requirements of a semiconductor memory system containing the synchronous signal generator.

Abstract: A DRAM interface circuit includes a clock generation circuit configured to generate a plurality of internal clock signals and skew data in response to a plurality of data strobe signals (DQS) received at an interface of the integrated circuit device. A data capture circuit is also provided. The data capture circuit is configured to capture a plurality of data streams (DQ) associated with the plurality of data strobe signals in a manner that sufficiently reduces skew between the captured data streams so that all of the plurality of data streams may then be reliably captured in-sync with a common clock.

Abstract: A shift amount measuring apparatus for measuring a phase shift amount of a signal under measurement which is input thereto includes a PLL circuit that generates a strobe signal which is synchronized with a reference signal, a CDR circuit that inputs, into the PLL circuit, a control signal which has a level determined in accordance with a difference in phase between the signal under measurement and the strobe signal, so as to achieve a predetermined difference in phase between the signal under measurement and the strobe signal, and a measuring circuit that, before and after the signal under measurement is phase-shifted, measures a value of the control signal when the predetermined difference in phase is achieved between the signal under measurement and the strobe signal, and calculates the phase shift amount of the signal under measurement based on a difference between the measured levels of the control signal.

Abstract: A semiconductor memory device, which includes a clock tree circuit for correcting the duty cycle of a clock. The device sets a beta ratio to cause a constant duty cycle by using a reference clock having a constant duty cycle in a test mode, and then applies the set beta ratio to a DLL clock outputted from a delay-locked loop. Then, when the duty cycle of the DLL clock, to which the beta ratio has been applied, is not constant, the duty cycle of the DLL clock is corrected in the delay-locked loop.