Abstract: A delay time of a reference clock CLK is changed to generate a memory control clock CLKd, a data value output from a write data generating section is written in a memory based on the memory control clock CLKd, while successively changing the delay time of the memory control clock CLKd with respect to the reference clock CLK, the data value written in the memory is read, and the delay time suitable for access to the memory is selected from the delay time of the memory control clock CLKd with respect to the reference clock CLK based on a comparison result of the data values.

Abstract: Techniques to bolster the security of an AlphaEta cryptosystem using spectral phase encoding. In one aspect, a spatial light modulator (SLM) is used to change the spectral code (spectral phase) of each optical bit in response to the output of an extended key generator based on a cryptographic algorithm. In other aspects, additional time and polarization modulations are used to maintain high security levels as well as good performance levels. Such methods are combined with traditional key generation methods such as key-distribution centers or one-way mathematical algorithms to bolster the security of traditional key generation as well.

Abstract: A circuit is described comprising a first (10) and a second circuit module (20) and a synchronization module (30). The first and the second module are mutually asynchronous, and are coupled by the synchronization module. The synchronization module (30) comprises: a transfer register (31) for storing data which is communicated between the two circuit modules, a control circuit (32) for controlling the register in response to a respective timing signal (St1, St2) from the first and the second circuit module, the control circuit comprising a control chain for generating a control signal (CR) for the transfer register (31). The control chain includes at least: a repeater (34) for inducing changes in the value of the control signal, at least one edge sensitive element (35) for delaying a change in the signal value until a transition in a selected one of the timing signals is detected.

Abstract: A clock signal generating circuit of a computer includes a first phase locked loop (PLL) circuit and a second PLL circuit. The computer includes a central processing unit (CPU) and a data bus. The first PLL provides a CPU clock signal to the CPU. A frequency of the CPU clock signal is the same as a working frequency of the CPU. The second PLL circuit provides a bus clock signal to the data bus. A frequency of bus clock signal is the same as a working frequency of the data bus. The data bus is to communicate with a graphic chip. The CPU clock signal is to control a working speed of the CPU. The bus clock signal is to control a working speed of the data bus.

Abstract: The invention provides an adjusting method of a system for changing a working frequency in an operation system for a computer system. The adjusting method includes establishing a look-up table, and detecting a newest value of the working frequency. An adjustment value can be obtained from the look-up table according to the newest value of the working frequency. In addition, a phase difference of a control signal of a memory is adjusted in the computer system according to the adjustment value and the working frequency is executed stably in optimum status according to the present invention.

Abstract: A bit slice circuit having transmit and receive modes of operation is described. The bit slice circuit comprises: first transmit circuitry and first receive circuitry operating in a first clock domain, wherein the first circuitry receives a first clock signal; second transmit circuitry and second receive circuitry operating in a second clock domain, wherein the second circuitry receives a second clock signal; transmit transition circuitry and receive transition circuitry, the transmit transition circuitry coupling the first transmit circuitry to the second transmit circuitry, the receive transition circuitry coupling the first receive circuitry to the second receive circuitry, wherein the transition circuitry receives the first and second clock signals; and a single phase mixer that generates the second clock signal, wherein the second clock signal has a first phase in the transmit mode of operation and second phase in the receive mode of operation.

Abstract: A memory card includes a clock I/O circuit, a data I/O circuit, a delay element, and an adjustment value holding circuit. The clock input/output circuit receives a first clock from a host apparatus. The data I/O circuit receives a second clock from the host apparatus in a write timing adjustment mode. The data I/O circuit transmits and receives data to and from the host apparatus in a data transfer mode. In the write timing adjustment mode, the delay element adjusts a phase of the second clock in accordance with the first clock so as to receive the data received in the data transfer mode in response to the first clock. The adjustment value holding circuit holds an adjustment value for the phase of the second clock adjusted. In the data transfer mode, the delay element adjusts a phase of the data in accordance with the adjustment value.

Abstract: Phase frequency detectors with limited output pulse width and related methods are provided. On exemplary phase frequency detector includes a first edge detector, a second edge detector, and a pulse reshaping controller. The first edge detector is for detecting first-type edges of a first signal to generate a first detection signal. The second edge detector is for detecting the first-type edges of a second signal to generate a second detection signal. The pulse reshaping controller is for receiving the first detection signal and the second detection signal, and for generating a first control signal to the first edge detector and generating a second control signal to the second edge detector. In addition, the pulse reshaping controller further generates a first output signal and a second output signal, wherein a pulse width of the first output signal is limited by the pulse reshaping controller.

Abstract: Serializing circuitry is provided that can multiplex multiple device output signals and that can drive time-multiplexed data signals on the bus wires of a data path of an electronic system. Bus registers placed at the ends of the bus wires can register or buffer the data signals transmitted over the bus wires. The registered signals may be passed on to deserializing circuitry for demultiplexing the data signals to provide parallel device input signals. The bus registers and the serializing/deserializing circuitry can be provided along signal paths that require additional latency.

Abstract: Systems and methods (“utility”) for providing more accurate clock skew measurements between multiple CPUs in a multiprocessor computer system by utilizing the cache control or management protocols of the CPUs in the multiprocessor system. The utility may utilize a time stamp counter (TSC) register of the CPUs in the multiprocessor computer system to detect the clock skew between the various CPUs in the system. Further, the delay between measurements of the TSC registers of the CPUs may be minimized by utilizing the features of the hardware cache control or management protocols of the computer system, thereby providing more accurate clock skew measurements.

Abstract: In emulation systems having a plurality of chips, data communicated between the chips needs to be synchronized. A receiver chip may push or pull on incoming data from an emitter chip in order to synchronize it with a receiver clock. Unexpected latency on the link between the emitter and receiver chips may also be adjusted for.

Abstract: Disclosed are a method and system to estimate the maximum error in the clock offset and skew estimation between two clocks in a computer system. The method comprises the steps of obtaining a first set of data values representing a forward delay between the first and second clocks, and obtaining a second set of data values representing a negative backward delay between the first and second clocks. The method comprises the further step of forming a lower convex hull for said first set of data values, and forming an upper convex hull for said second set of data values. First and second parallel lines are formed between the upper and lower convex hulls, and these parallel lines are used to estimate the worst case error for the offset, skew rate and dispersion of said first and second clocks.

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: Various embodiments utilize different counters or clocks, working in concert, to smooth out position information that is derived for a rendering/capturing device. Specifically, in at least some embodiments, each counter or clock has a different speed. A faster counter or clock is used to determine intra-transition position offsets relative to a slower counter or clock.

Abstract: The present invention is a method of asynchronous clock regeneration. The method includes synchronizing a first write pointer and a second write pointer, the first write pointer being an offline write pointer, the second write pointer being an online write pointer. The method further includes swapping at least one bit from the first write pointer with at least one bit of the second write pointer when the bits are static. The method further includes regenerating a DQS (Data Strobe Signal) clock.

Abstract: A mutual electrically connecting part mutually connects a plurality of information processing parts, wherein the mutual connecting part comprises a phase adjusting part configured to adjust a phase from each of the respective ones of the plurality of information processing parts; and the mutual connecting part further has a power supply cut signal transmitting part transmitting a power supply cut signal, indicating that power supply to any one of the plurality of information processing parts is cut, to the phase adjusting part corresponding to the information processing part; and an initializing part initializing the phase adjusting part corresponding to the information proceeding part for which power supply is cut, in response to the transmission of the power supply cut signal from the power supply cut signal transmitting part.

Abstract: A circuit for transitioning clocking speeds, or frequencies, is provided. With this circuit, a clocking circuit providing a first clock signal at a first clock frequency is coupled to a counter. A comparator and a first divider are coupled to an output of the counter. The first divider outputs a second clock signal at a second clock frequency. A second divider is interposed between the clocking circuit and the counter. A processor is coupled to an output of the first divider.

Abstract: A technique includes providing transmitters that are each associated with a data bit line of a bus, and each transmitter is clocked by an associated transmit clock signal. The technique includes determining a baseline offset to apply to a base clock signal to synchronize the base clock signal to a source clock signal of a source that supplies data to the transmitters. For each transmitter, an associated phase offset is determined to compensate for an associated skew. The phase of each transmit clock signal is controlled based on the associated phase offset and the baseline offset.

Abstract: A modular, numerical control having low-jitter synchronization includes a main computer and at least one controller unit which, starting from the main computer, are interconnected by serial data-transmission channels in the form of a series circuit. The at least one controller unit includes a first receiver unit for receiving a serial data stream arriving from the direction of the main computer, and a first transmitter unit for outputting a serial data stream. Also provided in the at least one controller unit is a clock recovery unit which derives a synchronous clock signal from the serial data stream arriving at the first receiver unit, and supplies it to the first transmitter unit which uses it as a transmission clock signal, so that the serial data stream arriving at the first receiver unit and the serial data stream output by the first transmitter unit are coupled to each other in phase-locked manner.

Abstract: A clock signal generator having first and second coarse delay circuits connected in series delays pulses of a reference signal having period Tp to produce pulses of the clock signal. The first coarse delay circuit delays pulses of the reference signal with a delay resolution of Tp/N seconds over a range spanning Tp seconds to produce pulses of an output signal. The second coarse delay circuit delays pulses of the output signal of the first coarse delay circuit over a range spanning Tp seconds with a delay resolution of TP/M seconds to provide pulses of the clock signal with a timing resolution of Tp/(M*N) seconds when the integers N and M are relatively prime.

Abstract: In one embodiment, a method includes receiving a first input stream, generating a first clock, sampling the first input stream based on the first clock, detecting a first phase difference between the first input stream and the first clock to generate a clock-correction signal and a first select signal, and generating a first recovered stream based on the first select signal. The method may additionally include receiving a second input stream, generating a second clock, sampling the second input stream based on the second clock, detecting a second phase difference between the second input stream and the second clock to generate a clock-correction signal and a second select signal, and generating a second recovered stream based on the second select signal. The method may further include adjusting the clocks based on the first and second clock-correction signals and combining the first and second recovered data streams to generate an output.

Abstract: In a data processing apparatus and method using a first-in first-out (FIFO), the data processing apparatus includes a first sampling circuit, a delay circuit, and a FIFO device. The first sampling circuit samples a logic state of input data in response to a first edge of a first clock signal and holds a result of the sampling. The delay circuit receives and delays the first clock signal by a predetermined delay time and outputs a second clock signal. The FIFO device processes the result of the sampling output from the first sampling circuit using a FIFO method in response to a first edge of the second clock signal output from the delay circuit.

Abstract: A semiconductor integrated circuit includes a flipflop holding and outputting input data according to a clock, the flipflop having: an input end to which data is input; an output end from which data is output; a first logic gate connected between the input end and the output end, the first logic gate operating according to the clock; a second logic gate connected between the first logic gate and the output end, the second logic gate operating according to the clock; and a buffer circuit. An input of the buffer circuit is connected to a node between the first logic gate and the input end. An output of the buffer circuit is connected to a node in an output side of the first logic gate. The buffer circuit transitions according to an enable signal from a high impedance state to a state in which a signal can be transmitted.

Abstract: A method of receiving data packets. In the method of receiving data packets, a determination is made as to whether a received data packet is received out of an expected order. If the determining step determines a received packet is out of the expected order, a time period is calculated to wait for one or more missing data packets based at least in part on an expected time of receiving the one or more missing data packets.

Abstract: In a preferred embodiment, the invention provides a circuit for reducing bit error rates. A data recovery circuit recovers data from a first HSS link to differential bit pair inputs. Data from the differential bit pair outputs of the data recovery circuit drive differential bit pair inputs to a plurality of FIFOs. The data is then driven from a parallel output of the plurality of FIFOs to the parallel input of a synchronizer. The data is then driven from the parallel output of the synchronizer to the parallel input of a serializer. The serializer, through different bit pair outputs, drives a second serial HSS link.

Abstract: A double data rate elastic interface in which programmable latch stages provide an elastic delay, preferably on the driving side of the elastic interface. However, the invention is not limited to the driver side/chip, it can be implemented in the receiver side/chip as well. However, since the receiver side of an elastic interface already has complicated logic, the invention will be usually implemented on the driving side. The programmable latch stages on the driving chip side of the interface, can often operate at the local clock frequency (the same frequency as the elastic interface bus clock frequency), which in turn is half of the double data rate at which the receiving latch stages operate, thereby decreasing the logic and storage resources in the interface receivers. The programmable latch stages can also be used in the case that the local clock frequency is twice the elastic interface bus clock frequency.

Abstract: A apparatus is provided for buffering data between a memory controller and a DRAM. The apparatus includes a phase locked loop (PLL), a phase interpolator for aligning a phase of an output clock signal in response to a phase aligning control word, and a non-volatile storage location permanently storing the phase aligning control word. The phase aligning control word is determined through an initial training procedure of the device under predetermined training conditions of at least a supply voltage level and a temperature, and the predetermined training conditions are set so as to optimize the phase alignment of an edge of the output clock signal with respect to the buffered data signal.

Abstract: A method and a system of sharing of a clock by an electronic circuit between at least one first task clocked by at least one first counter and at least one second task clocked by a second counter, the two counters varying at the rate of said clock, the content of the first counter plus or minus an offset value being, on each execution of the second task, assigned to the second counter.

Abstract: Methods and apparatuses for compensating for differences in communication system transmit and receive clock signal frequencies include buffer timing modification and sample addition. In buffer timing modification, a buffer clock signal is interrupted as needed to slow the rate of data through the buffer. In sample addition, pseudo samples are inserted into a data stream to compensate for timing differences.

Abstract: Clock skew may be detected measured and compensated for using phase detectors and variable delay adjusters. Phase detectors may be distributed throughout a clock distribution network and may be configured to analyze two clock signals to determine how often one signal leads the other. The output of the phase detectors may be measured and counted over a large number of clock cycles. The difference between the number of times one signal leads or lags behind the other may be used to determine the amount of delay to apply to the leading clock signal in order to minimize (reduce) skew between the two clock signals. The same techniques for detecting and measuring clock skew may also be used to detect and measure jitter in the clock signals. By configuring variable delay adjusters on clock signals, the amount of jitter in the clock signals can be measured or characterized.

Abstract: A memory test system injects phase jitter in memory command, address and write data signals in respective pin groups. A phase interpolator receiving a clock signal is provided for each of the pin groups to generate respective delayed clock signals. The phase shift produced by each of the phase interpolators is determined by delay control values, which are passed to the phase interpolators from respective memory arrays. Each of the memory arrays stores at each address a next address along with a delay control value. The next address is used to access the memory array to obtain next delay control value. The delayed clock signals are applied to a clock input of a respective set of registers for each pin group, and a data input of each of the registers receives one of the memory device signals in the respective pin group.

Abstract: A system and method for using variable delay adjusters located at various points across an integrated circuit to measure clock skew and jitter for clock signals of the integrated circuit. A delay controller of the integrated circuit may measure and compensate for clock skew detected between two clock signals by configuring variable delay adjusters located inline with the respective clock signals. Such a delay controller may also use the variable delay adjusters to correct duty cycle errors in a clock signal and may further utilize the variable delay adjusters to measure and characterize jitter detected on the clock signals.

Abstract: Techniques are described for synchronizing multiple time-based data streams with independent clocks wherein relationships between clock rates of timing devices associated with the time-based data streams are determined, and based on these relationships, times in at least one of the time-based data streams may be translated to times in any of the other time-based data streams despite the data streams having independent clocks.

Abstract: The present invention relates to a system and method for processing the read and write operations in a memory architecture. The system processing the read and write operations includes at least one local memory block and a synchronously controlled global controller coupled to the local memory block and adapted to extend the high portion of a clock pulse. The method for processing the read and write operations includes skewing a clock pulse using at least one word line interfacing with the global controller.

Abstract: A signal processor includes a reference clock generator configured to generate a reference clock as a synchronization reference for a signal processing. A counter is configured to count the reference clock. A frequency controller is configured to sample a count value of the counter by utilizing an input clock, to compare an increment value increased from the last sampled value with an expected value, and to control a frequency of the reference clock in accordance with a comparison result.

Abstract: Occurrence and propagation of glitches caused by changing the path layout are suppressed, thereby reducing the power consumption. An array-type processor comprises a plurality of processor elements and can change the path layout relating to data transmission/reception between the processor elements depending on clock cycle. Each processor element comprises a layout information memory 11 that stores a layout information indicating signal relating to the layout of the paths, a delay adjusting circuit 12 that adjusts the timing of a layout information indicating signal Pin outputted from the layout information memory 11 at every clock cycle, and a wiring connection circuit 13 that changes a path to at least one of the other processor elements (PE) or function unit(s) (a register file unit 14 and an arithmetic logic unit 15) based on a layout information indicating signal Pout whose timing has been adjusted.

Abstract: Embodiments directed to a memory device and a memory controller that continue to operate in a low-power mode during the period required for analog timing circuitry to initialize and become usable, are described. During a low-speed to high-speed transition mode of operation for a high-speed interface, timing circuitry of the interface between the memory device and memory controller locks to a forward clock signal concurrent with the continued operation of the interface in low-speed mode. A reference clock signal configured to operate at a rate that provides both a high-speed mode and a low-speed mode and which is used as a single rate clock allows phase detection and correction circuitry to be disabled, thus allowing the idle period caused by a transition from low-speed mode to high-speed mode to be significantly reduced.

Abstract: A memory card includes a memory controller configured to perform control for sending and receiving a command signal, a response signal, a data signal, and a status signal in synchronization with a clock signal, and a memory-side pattern signal storage unit configured to store a tuning pattern signal to be sent to a host device. The tuning pattern signal is used by the host device to adjust the phase of the clock signal for use as a sampling clock signal. The memory card sends a first tuning pattern signal through a command line and a second tuning pattern signal through a data line concurrently.

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: 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 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: Precise timing information produced by a block average module may be provided to signal processing circuitry. A sample period value generator may produce samples of the input data period values. A progressive block averaging computation may be applied to the generated input data period value samples. The output of the progressive block averaging computation may be used as the precise input sample rate information. The precise input sample rate information may in turn drive a signal processing application. The precision of the clock information may be increased with an increase in startup overhead.

Abstract: A memory controller comprises a DQ path, a DQS path, a delay element, a flip flop, and an adjustment unit. The DQ path receives and passes a data signal, and outputs a delayed data signal. The DQS path receives and passes a data strobe signal. The delay element is coupled to the DQS path, receiving the data strobe signal to generate a compensated data strobe signal having a calibrated latency. The calibrated latency is determined by an adjustment signal. The flip flop is coupled to the data signal path and the delay element, sampling the delayed data signal by the compensated data strobe signal to generate an output data. The adjustment unit generates the adjustment signal according to the output data. The adjustment unit performs a calibration to adjust the adjustment signal, thus the calibrated latency is adjusted.

Abstract: Methods and systems for determining a memory access time are provided. A first phase skew is measured between a first clock signal used by a memory and a second clock signal used as a reference clock signal. Then, a second phase skew is measured between a delayed version of the first clock signal output by the memory when the memory completes a given read operation and the second clock signal. The memory access time is determined based on the first and second phase skews.

Abstract: A signaling system includes a signaling path, a master device coupled to the signaling path, a slave device coupled to the signaling path, and a clock generator. The slave device includes timing circuitry to generate an internal clock signal having a phase offset relative to a clock signal supplied by the clock generator, the phase offset being determined at least in part by a signal propagation time on the signal path.

Abstract: Systems and methods for ensuring proper phase alignment of audio signals which are processed by separate hardware channels in an audio amplification system. In one embodiment, the phase alignment is controlled by determining the number of audio data samples which are stored in the input buffers of multiple audio amplification units and controlling reads from the input buffers to minimize the difference between an actual read-write pointer differential and a target differential. In a master unit, the target differential is a predetermined target value corresponding to a desired delay in the buffer. The actual pointer differential of the master unit is passed to one or more slave units. The actual pointer differential of the master unit is used as the target differential of the slave units. The pointer differentials of the slave units are thereby driven to track the pointer differential of the master unit, keeping the units synchronized.

Abstract: A dual clock interface for an integrated circuit is described. An integrated circuit includes interface circuitry. The interface circuitry has a hardwired logic block. The hardwired logic block has a clock divider circuit coupled to receive a user clock signal and a core clock signal for dividing the core clock signal responsive to a frequency of the user clock signal to provide a divided clock signal with edges aligned to the core clock signal. The divided clock signal has the frequency of the user clock signal and a phase relationship of the user clock signal. User-side logic is coupled to receive the divided clock signal for the controlled passing of information responsive to the divided clock signal. Core-side logic is coupled to receive the core clock signal for the controlled passing of information responsive to the core clock signal.

Abstract: A method of controlling a clock frequency is disclosed and includes monitoring a plurality of master devices that are coupled to a bus within a system. The method also includes receiving an input from at least one of the plurality of master devices. The input can be a request an increase to the clock frequency of the bus. Further, the method includes selectively increasing the clock frequency of the bus in response to the request.

Abstract: A bus receiver receives at least one first signal and a second signal both generated from a chip connected to a parallel bus. The bus receiver includes a receiving module and a deskewing module. The receiving module is electrically connected to the parallel bus and receives the first signal and the second signal transmitted through the parallel bus. The deskewing module is electrically connected to the receiving module and deskews the phase of the first signal and the phase of the second signal. The first signal and the second signal are in the same phase.

Abstract: The present invention relates to an apparatus and method for throttling a clock of a bus used for data exchange between devices in a computer such as a portable computer or notebook. Methods according to the invention can set a throttle rate of a clock to a predetermined initial value, detect a current remaining battery capacity or a current load to the CPU, and adjust the set throttle rate to a prescribed or calculated value according to the detected remaining battery capacity or the CPU load. Thus, power consumption is reduced, and, in the case of a battery-powered computer, battery life and operating time are extended.