Abstract: Methods and systems for an optoelectronic built-in self-test (BIST) system for silicon photonics optical transceivers may include an optoelectronic transceiver having a transmit (Tx) path and a receive (Rx) path, where the Rx path includes a main Rx path and a BIST loopback path. The system may generate a pseudo-random bit sequence (PRBS) signal, generate an optical signal in the Tx path by applying the PRBS signal to a modulator, communicate the optical signal to the BIST loopback path and convert the optical signal to an electrical signal utilizing a photodetector, where the photodetector is a replica of a photodetector in the main Rx path, and assess the performance of the Tx and Rx paths by extracting a PRBS signal from the electrical signal. The transceiver may be on a single complementary-metal oxide semiconductor (CMOS) die, or on two CMOS die where a first comprises electronic devices and a second comprises optical devices.

Abstract: A serial, half-duplex start/stop event detection circuit comprises a stop detection flip-flop clocked by a serial data input that takes a serial clock input as an input and generates a stop signal output indicative of a stop event. A start detection flip-flop, clocked by an inverted copy of the serial data input, takes the serial clock input as an input and generates a start signal output indicative of a start event. A first buffer flip-flop, clocked by an inverted copy of the serial clock input, takes the start signal output as an input and generates a first delayed start signal output. Similarly, a second buffer flip-flop, clocked by the serial clock input, takes the first delayed start signal output as an input and generates a second delayed start signal output. The second delayed start signal output resets at least one of said stop detection, start detection or first buffer flip-flops.

Abstract: A receiver with clock phase calibration is disclosed. A first sampling circuit generates first digital data based on an input signal, a sampling phase of the first sampling circuit controlled by a first clock signal. A second sampling circuit generates second digital data based on the input signal, a sampling phase of the second sampling circuit controlled by a second clock signal. Circuitry within the receiver calibrates the clocks in different stages. During a first calibration stage, a phase of the second clock signal is adjusted while the first digital data is selected for generating the output data. During a second calibration stage, a phase of the first clock signal is adjusted while the first digital data is selected for the output data path.

Abstract: The disclosure relates to a module for a radio receiver. The module comprises an input terminal; an output terminal; a main signal path for communicating in-phase and quadrature signals between the input terminal and the output terminal; and a second signal path. The second signal path is connected in parallel with the main signal path and is configured to: extract in-phase and quadrature signals from the main signal path; filter the extracted in-phase and quadrature signals; detect an error in the filtered, extracted in-phase and quadrature signals; and apply a correction to in-phase and quadrature signals on the main signal path based on the error.

Abstract: Apparatus and methods for clock and data recovery (CDR) are provided herein. In certain configurations, a first CDR circuit captures data and edge samples from a first input data stream received over a first lane. The data and edge samples are used to generate a master phase signal, which is used to control a phase of a first data sampling clock signal used for capturing the data samples. Additionally, the first CDR circuit generates a master phase error signal based on changes to the master phase signal over time, and forwards the master phase error signal to at least a second CDR circuit. The second CDR circuit processes the master phase error signal to generate a slave phase signal used to control a phase of a second data sampling clock signal used for capturing data samples from a second input data stream received over a second lane.

Abstract: An edge interval measuring block measures a first same-edge interval. A bit number detector detects the number of bits in the first same-edge interval based on reference bit length information and detects a first number of bits in a same-value interval between consecutive bits of the same value by subtracting the number of bits in the known bit stream from the number of bits in the first same-edge interval. The edge interval measuring block then measures a second same-edge interval. The bit number detector detects the number of bits in the second same-edge interval based on the reference bit length information and detects a second number of bits in a bit stream of consecutive bits of the same value opposite to the value in the same-value interval by subtracting the first number of bits from the number of bits in the second same-edge interval.

Abstract: A data processing device includes a clock converter, a data converter, and an error detector. The clock converter is configured to receive a first clock signal, convert the first clock signal into a second clock signal, and output the second clock signal. The data converter is configured to receive first data, convert the first data into second data using the second clock signal, and output the second data. The error detector is configured to check whether the first clock signal is in a first clock state or a second clock state upon the first data transitioning to a first data state, and output an enable signal to the clock converter upon determining that the first clock signal has transitioned to the first clock state from the second clock state.

Abstract: Exemplary embodiments provide a computer-implemented method for generating a modulated acoustic carrier signal for wireless transmission from a speaker of a transmit device to a microphone of a receive device. Aspects of the exemplary embodiments include converting a message to binary data; modulating one or more selected frequencies for one or more acoustic carrier signals based on the binary data to generate one or more modulated acoustic carrier signals; filtering the one or more modulated acoustic carrier signals to remove any unintended audible harmonics created during modulation, including; equalizing the modulated acoustic carrier signal to pre-compensate for known degradations that will occur further along a signal path; setting a level of the modulated acoustic carrier signal for the intended application; and storing the modulated acoustic carrier signal in a buffer for subsequent output and transmission by the speaker.

Abstract: According to one embodiment, a channel phase estimation apparatus includes a phase memory, subtractor, multiplier, and adder. The phase memory is configured to store a first phase estimation value up to a (k?1)-th (for k=1, 2, . . . , K) symbol. The subtractor is configured to calculate a difference value between a phase value of one carrier of a k-th symbol and the first phase estimation value. The multiplier is configured to multiply the difference value by a weight. The adder is configured to add a value output from the multiplier and the first phase estimation value to output a second phase estimation value up to the k-th symbol.

Abstract: A source-synchronous capture unit on a receiving circuit includes a first first-in-first-out (FIFO) unit operable to synchronize a write enable signal to generate a synchronized write enable signal that is synchronized with a first free running clock associated with a memory external to the receiving circuit. The write enable sign is generated in response to a read operation by the receiving circuit. The source-synchronous capture unit also includes a second FIFO unit operable to store data from the memory in response to the first free running clock and the synchronized write enable signal, and to output the data in response to a second free running clock associated with the receiving circuit and a read enable signal.

Abstract: According to an embodiment, there are provided a capacitor DAC for generating an output signal in accordance with a connection state of a capacitor element, a reference voltage generation circuit for supplying a reference voltage to the capacitor DAC, a comparator for outputting a comparison result in accordance with the output signal, a successive approximation register for outputting a digital signal in accordance with the comparison result, and a control circuit for controlling a connection state of the capacitor element in accordance with the comparison result and comparing an ideal code with a digital signal obtained by sampling a predetermined voltage, thereby correcting an error of the digital signal.

Abstract: The present invention discloses a digital self-timed timer for measuring the passage of time; a digital self-timed pulse generator for generating both continuous and finite pulse sequences; and a digital self-timed data receiver for recovering data from an asynchronous, two-wire bit-channel. Being self-timed, a disclosed self-timed timer measures time as a function of logic delays incurred while executing a sequence of internal state transitions. A pulse generator supports both a triggered pulse mode and continuous clock generation; pulse widths and pulse intervals are programmable. A data receiver may recover a data bit from each received two-bit code word and outputs recovered data and an associated write strobe for each recovered datum.

Abstract: A system and method are provided for generating a jitter-attenuated clock using an asynchronous gapped clock source. The method accepts a first reference clock having a first frequency. Using the first reference clock, an asynchronous gapped clock is generated having an average second frequency less than the first frequency. A dynamic numerator (DN) and dynamic denominator (DD) are iteratively calculated for the gapped clock. Then, DN and DD are averaged. In response to the averaging, an averaged numerator (AN) and an averaged denominator (AD) are generated. Finally, the first frequency (first reference clock) is multiplied by the ratio of AN/AD to create a jitter-attenuated second clock having the second frequency.

Abstract: Correcting phase error in a two-channel TIADC system in a manner that is independent of the Nyquist zone(s) occupied by the input signal. In the preferred approach this is done using the gradient of a phase error estimate. The gradient may be determined from a simplified expression of linear regression; the direction of the adaptation is then controlled by the sign of the gradient. The adaptive algorithm converges to the optimal value regardless of the Nyquist zone occupied by the input signal.

Abstract: Embodiments of a synchronization circuit are described. This synchronization circuit includes multiple selectively coupled synchronization stages which are configurable to synchronize data and control signals between a first time domain and a second time domain, where the synchronization can be performed based on asynchronous or synchronous events associated with either the first time domain or the second time domain. Additionally, the synchronization circuit includes control logic, coupled to the synchronization stages, which is configured to adapt a number of synchronization stages used to synchronize the data and the control signals based on an estimate of a probability of metastability persisting to an output of the synchronization circuit during the synchronization.

Abstract: A sigma-delta modulator includes a front portion and a hybrid portion to form a loop filter. The front portion includes integrator(s) and feed-forward path(s), and is arranged to provide a front signal by combining signals of the integrator(s) and feed-forward path(s). The hybrid portion is coupled to the front portion, and arranged to provide a filtered signal by combining an integration of the front signal and a weighting of the front signal. The filtered signal is quantized, converted from digital to analog, and fed back to the loop filter.

Abstract: Methods and apparatus are provided for pseudo asynchronous testing of receive paths in serializer/deserializer (SerDes) devices. A SerDes device is tested by applying a source of serial data to a receive path of the SerDes device during a test mode. The receive path substantially aligns to incoming data using a bit clock. A phase is adjusted during the test mode of the bit clock relative to the source of serial data to evaluate the SerDes device. The source of serial data may be, for example, a reference clock used by a phase locked loop to generate the bit clock. The phase of the bit clock can be directly controlled during the test mode, for example, by a test phase control signal, such as a plurality of interpolation codes that are applied to an interpolator that alters a phase of the bit clock.

Abstract: A signal generation system maintains a phase relationship between output signals of first and second signal generators even when the sampling clock frequency is changed. The signal generators are coupled via a communication means including a dedicated cable where the delay amount of the communication means is known and fixed. The first signal generator provides sampling clock, sequence clock and trigger/event signals to the second signal generator and CPUs of the generators share information via the cable. When the frequency of the sampling clock is changed, the CPU of the first or second signal generator calculates the clock number of the frequency changed sampling clock equivalent to the delay amount of the communication means. A delay circuit of the first signal generator 100 delays the waveform data by one sampling clock based on the calculated value for adjusting phase relationship between the waveform data in the signal generators 1.

Abstract: A device is described for receiving data transmitted using asynchronous data transmission technology, in particular audio and video data, which receives a clock signal, having a memory device (17), which stores the received data for the required period of time in order to compensate for transmission delays (Cell Delay Variation). The clock signal is sent to the memory device (17) for reading out the data. Furthermore, a method is described for receiving data signals using asynchronous data transfer technology, with the received data signals being temporarily stored and read out at the studio clock rate.

Abstract: A system and method are provided for determining a time for safely sampling a signal of a clock domain. In one embodiment, a frequency estimate of a first clock domain is calculated utilizing a frequency estimator. Additionally, a time during which a signal from the first clock domain is unchanging is determined such that the signal is capable of being safely sampled by a second clock domain, using the frequency estimate. In another embodiment, a frequency estimate of a first clock domain is calculated utilizing a frequency estimator. Further, a phase estimate of the first clock domain is calculated based on the frequency estimate, utilizing a phase estimator. Moreover, a time during which a signal from the first clock domain is unchanging is determined such that the signal is capable of being safely sampled by a second clock domain, using the phase estimate.

Abstract: A circuit with adaptive synchronization and a method thereof is provided. The synchronous receiving circuit adaptively adjusts the timing of a clock signal generated therein for receiving data without accompanying a clock signal for synchronization. The synchronous receiving circuit includes a clock generator, an edge detector, a synchronization unit and a latch. The clock generator generates a first clock signal according to an input data signal. The edge detector detects edges to generate an indication signal. The synchronization unit is coupled to the clock generator and the edge detector, and adaptively adjusts the first clock signal according to the indication signal. The latch latches the input data signal according to the adjusted first clock signal.

Abstract: A data receiver circuit includes: a clock/data recovery circuit to recover a clock and data from a received signal; a fixed pattern generation circuit to generate fixed pattern data; a first selection circuit to select and output one of the fixed pattern data generated by the fixed pattern generation circuit and recovered data recovered by the clock/data recovery circuit; a second selection circuit to select and output one of a reference clock and recovered clock recovered by the clock/data recovery circuit; and a switching circuit to make the first selection circuit output the fixed pattern data and to make the second selection circuit output the reference clock, when an input signal is lost or the clock/data recovery circuit is in a loss-of-lock state.

Abstract: Systems, methods, and circuits extract data from an oversampled data stream in the presence of noise and/or jitter. Pointers decide which data samples of the oversampled data stream are extracted. Some of the pointers occurring right after a data transition are positioned based on the location of previous pointers, rather than using the data transition points as occurs during an alignment. Settings such as the frequency of how often a pointer is aligned with a data transition and a maximum adjustment amount during an alignment may be programmable.

Abstract: For reconstructing a data clock from asynchronously transmitted data packets, a control loop is provided which includes a controlled oscillator. An input signal of the control loop is generated on the basis of the received data packets. At least one high-pass type filter is provided in a signal path of the control loop. The data clock for the synchronous output of data is generated on the basis of an output signal of the controlled oscillator.

Abstract: Methods and apparatus are provided for pseudo asynchronous testing of receive paths in serializer/deserializer (SerDes) devices. A SerDes device is tested by applying a source of serial data to a receive path of the SerDes device during a test mode. The receive path substantially aligns to incoming data using a bit clock. A phase is adjusted during the test mode of the bit clock relative to the source of serial data to evaluate the SerDes device. The source of serial data may be, for example, a reference clock used by a phase locked loop to generate the bit clock. The phase of the bit clock can be directly controlled during the test mode, for example, by a test phase control signal, such as a plurality of interpolation codes that are applied to an interpolator that alters a phase of the bit clock.

Abstract: A receiver may include a clock and data recovery circuit, a detection circuit and a sampling clock generator. The clock and data recovery circuit may receive first data and sample the first data to generate recovered data in response to a reception sampling clock signal. The detection circuit may detect a frequency difference between a transmission sampling clock signal and the reception sampling clock signal by comparing the first data and the reception sampling clock signal to generate a frequency difference detection signal. The sampling clock generator may generate the reception sampling clock signal based on the frequency difference detection signal and a first reference clock signal. Therefore, a communication system including the receiver may effectively reduce a jitter noise.

Abstract: An adaptive equalizer for high-speed serial data comprises a programmable equalizer for equalizing an input serial data signal to generate an equalized serial data signal, wherein the equalization is based on an optimal equalization mode; a signal quality meter for computing an eye width indication based on the equalized serial data signal, wherein the eye width indication is an indicative of the quality of the equalized serial data signal; and a decision unit for determining the optimal equalization mode based on the eye width indication.

Abstract: A mobile device that incorporates the MIPI D-PHY specification has data lanes for carrying data between electronic modules within the device. The data lanes may incorporate a spaced-one-hot approach for asynchronously receiving a data signal over a two-wire interface. A two-wire receive interface is provided that uses an exclusive-NOR to capture a timing signal along with a set-reset flip-flop which holds the state of the data line so that a D flip-flop that is clocked on the falling edge of the timing signal received from the exclusive-NOR gate can sample the data and provide an accurate asynchronous data output.

Abstract: System and method for a four-slot asynchronous communication mechanism with increased throughput. The system may include a host system and a client device. The host may comprise a data structure with four (two pairs of) slots and first information indicating a status of read operations from the data structure by the host. The client may read the first information from the host. The client may read second information from a local memory. The second information may indicate a status of write operations to the data structure by the client. The client may determine a slot of the data structure to be written. The slot may be determined based on the first information and the second information and may be the slot which has not been written to more recently of the pair of slots which has not been read from most recently. The client may increment a value of a counter. The value of the counter may be useable to indicate which slot has been written to most recently.

Abstract: A method and system of sample recovery is disclosed. In one embodiment, a method includes selecting initially in an arbitrary manner, a current symbol from a sequence of input samples, comparing a symbol timing estimate associated with the current symbol to a predetermined threshold, selecting a future symbol strobe that is ahead at an interval equivalent to a predetermined interval based on the comparison of the symbol timing estimate to the predetermined threshold, selecting a future symbol from the sequence of samples corresponding to the future symbol strobe, assigning the future symbol to the current symbol, which is the recovered symbol, rearranging the recovered symbols to form Pulse Code Modulated (PCM) samples of a bandlimited signal at a sample rate which is derived from the recovered symbol rate, and resampling at the sample rate of the receptor block which receives the recovered PCM samples.

Abstract: A method and apparatus for processing a radio frequency (RF) signal is provided. The method includes generating a periodic square wave local oscillator (LO) signal of a first phase, a periodic square wave LO signal of a second phase, and a chopping signal. The method further includes coding the periodic square wave LO signal of the first phase and the periodic square wave LO signal of the second phase synchronously with the chopping signal to generate a first set of synchronized signals (116, 118) and a second set of synchronized signals (120, 122), respectively. A phase difference between the first phase and the second phase is a predefined value. The RF signal is processed with the first set of synchronized signals (116, 118) and the second set of synchronized signals (120, 122) to obtain an in-phase intermediate frequency (IF) signal (132) and a quadrature-phase IF signal (142), respectively.

Abstract: The present invention is an improved system and method for detecting the leading edge of a waveform. More specifically, the invention relates to detecting the leading edge of an ultra wideband waveform. The invention requires locking to the ultra wideband waveform at a lock reference time, and sampling the ultra wideband waveform during one or more time windows relative to the lock reference time to identify one or more leading edge candidate times based on one or more detection criterion. The ultra wideband signal is sampled at a band limited Nyquist rate that avoids aliasing within a band of interest of the ultra wideband waveform, but allows aliasing outside of the band of interest to minimize the number of samples for leading edge detection processing.

Abstract: Apparatus and methods for accessing a wireless telecommunications network by transmitting a random access signal. The random access signal includes a random access preamble signal selected from a set of random access preamble signals constructed by cyclically shift selected root CAZAC sequences. The random access signal may be one or more transmission sub-frames in duration, the included random access preamble sequence's length being extended with the signal to provide improved signal detection performance in larger cells and in higher interference environments. The random access signal may include a wide-band pilot signal facilitating base station estimation of up-link frequency response in some situations. Each of the plurality of available random access preamble sequences may be assigned a unique information value. The base station may use the information encoded in the random access preamble to prioritize responses and resource allocations.

Abstract: A method and a circuit for obtaining asynchronous demapping clock. The method includes: obtaining a smoothed clock with even gaps in accordance with data to be demapped and a corresponding clock signal; performing phase locking in accordance with a signal reflecting writing and reading conditions of data of a First In First Out (FIFO), to obtain a clock signal required for demapping. The method can effectively filter off jittering created during asynchronous mapping/demapping processes and may ensure a high-performance clock output. Furthermore, the method is applicable to not only mapping from OTN to SDH but also other asynchronous demapping processes, e.g., mapping from SDH to OTN, and thereby effectively improving the performance of data demapping.

Abstract: Apparatus, systems, and methods operate to receive a sufficient number of asynchronous input tokens at the inputs of an asynchronous apparatus to conduct a specified processing operation, some of the tokens decoded to determine an operation type associated with the specified processing operation; to receive an indication that outputs of the asynchronous apparatus are ready to conduct the specified processing operation; to signal a synchronous circuit to process data included in the tokens according to the specified processing operation; and to convert synchronous outputs from the synchronous circuit into asynchronous output tokens to be provided to outputs of the asynchronous apparatus when the synchronous outputs result from the specified processing operation. Additional apparatus, systems, and methods are disclosed.

Abstract: A frame synchronization apparatus and method for controlling a frame synchronization process. The frame synchronization apparatus includes a correlation-value computation section; an IQ component select section; and a synchronization-signal outputting section. The correlation-value computation section computes a correlation value representing a correlation between a known delay wave detection series and a received delay wave detection series. The IQ component select selects a larger one of absolute values representing the amplitudes of I and Q. The synchronization-signal outputting section carries out a peak detection process to detect a peak in pieces of data arranged along a time axis to form a correlation-value series and output a frame synchronization signal for said input signal in accordance with a result of said peak detection process.

Abstract: The invention relates to a method of transmitting time information relating to the clock of the source of a sending part consisting in using a fixed latency indicator signal to authorize the source to insert time information used to slave the clock of the decoder of the associated receiving part to its clock.

Abstract: A system for controlling the transfer of a signal sequence in a first clock domain to a plurality of other clock domains. The system comprising: detecting circuitry for detecting receipt of the signals from the clock domains and setting an update signal when all of the signals received from the clock domains have a common state; and gating circuitry for receiving the update signal and operable, when the update signal is set, to allow a next signal in the sequence to be received at the input of the first circuitry.

Abstract: Disclosed is a system and method for a clock and data recovery (CDR) circuit. A phase selection circuit (PSC) generates a signal comprising frequency and phase. A voltage controlled oscillator (VCO) connected to the PSC generates a clock signal. The clock signal controls the frequency of the signal. The CDR circuit also includes a phase adjustment signal generator connected to the PSC for generating a phase adjustment signal. The phase adjustment signal controls the phase of the signal.

Abstract: A method is disclosed, including identifying a preamble in a frame, where the preamble has a preamble length 1. M data items received in succession are stored. The m data items once divided into n portions, where the data items in each portion have respectively been received at successive times and where m and n are natural numbers and the following applies to m and n: m>n, m>1, n>1. The n portions are respectively correlated to the expected values to form component correlation results. Delaying the component correlation results, with at least two component correlation results being delayed by different lengths. The method also includes combining the delayed component correlation results to form a total correlation value. The total correlation value is used to determine whether the m received data items contain the preamble of a frame.

Abstract: Apparatus, systems, and methods operate to receive a sufficient number of asynchronous input tokens at the inputs of an asynchronous apparatus to conduct a specified processing operation, some of the tokens decoded to determine an operation type associated with the specified processing operation; to receive an indication that outputs of the asynchronous apparatus are ready to conduct the specified processing operation; to signal a synchronous circuit to process data included in the tokens according to the specified processing operation; and to convert synchronous outputs from the synchronous circuit into asynchronous output tokens to be provided to outputs of the asynchronous apparatus when the synchronous outputs result from the specified processing operation. Additional apparatus, systems, and methods are disclosed.

Abstract: An eyewidth of a data signal is determined by steps including: (a) recovering a phase of a clock from a data signal as a sampling clock; (b) shifting the phase of the sampling clock away from the first phase by a count multiplied by predetermined phase amount; (c) sampling the data signal with the shifted sampling clock phase to obtain sample data; d) determining whether the sample data contains error; (e) when the sample data does not contain error, recovering the phase of the clock from the data signal again for use as the first phase of the sampling clock, increasing the count value and repeating steps (b) through (e); and f) when the sample data contains error, determining the eyewidth based on the last shifted phase of the sampling clock prior to determining that the sample data contains error.

Abstract: A clock generator is provided for a transmitter in a transceiver adapted to communicate data over a serial data link. The transceiver includes a clock data recovery circuit recovers a receive clock signal and outputs a reference clock signal. The clock generator includes a local clock, a frequency difference detector, and a fractional-N frequency synthesizer. The local clock outputs a local clock signal. The frequency difference detector outputs a fractional frequency difference signal based on a frequency difference between the local clock signal and the reference clock signal. The fractional-N frequency synthesizer outputs a transmit clock signal having a same frequency as the recovered receive clock signal.

Abstract: A logic circuit comprises a logic module comprising a functional logic block supplying a functional result, and a functional flip-flop receiving the functional result and supplying a synchronous result. A module for checking the functional logic block comprises a checking logic block executing the same logic function as the functional logic block and supplying a checking result, checking synchronous flip-flops for applying data present at the input of the functional logic block to the input of the checking logic block, and means for comparing the functional result and the checking result and for supplying a first error signal.

Abstract: A special data including communication wire continuous dominant levels of a number of N more than the transceiving bit number of n of communication wire continuous dominant levels, set in a character as one unit of communication data, can be transceived by a widely-used serial communication interface such that a predetermined transmission rate is changed to n/N times the transmission rate only when the special data is transmitted, whereby the special data can be easily transceived at a low cost.

Abstract: The present invention provides an event edge synchronization system and a method of operating the same. In one embodiment, the event edge synchronization system includes: (1) a first clock zone device configured to generate an event signal based upon a first clock rate, (2) a second clock zone device configured to operate at a second clock rate, which is asynchronous with the first clock rate and (3) a synchronous notification subsystem configured to receive the event signal, synchronize the event signal to the second clock rate based upon an edge transition of the event signal and the second clock rate, and generate a synchronous notification signal therefrom.

Abstract: An adaptive variable length pulse synchronizer including a state keeper circuit, an asynchronous pulse edge detection circuit, a data synchronization circuit, and a pulse edge synchronization circuit. The state keeper circuit detects a leading edge of the asynchronous pulse. The asynchronous pulse edge detection circuit detects a trailing edge of the asynchronous pulse after the state keeper circuit has detected the leading edge. The asynchronous pulse edge detection circuit further provides a pulse synchronized with a clock signal after the asynchronous pulse has been detected. The data synchronization circuit latches the asynchronous data and provides the synchronous data in response to the synchronous pulse. The pulse edge synchronization provides the synchronous ready signal after synchronous data has been provided.

Abstract: Presented herein are systems and methods for clock rate determination. A bitstream is sampled by sampling a transmitted clock signal at a rate corresponding to a receiver clock signal, and measuring an average number of consecutive samples that have a same state selected from a first state and a second state.

Abstract: An asynchronous data transmitting apparatus includes data signal transmission lines; two control transmission lines having a minimum delay and maximum delay respectively; a transmitter; and a receiver. The transmitter includes a data transmitting unit that transmits a data signal through the data signal transmission lines, depending on a transmit clock; and control transmitting units that transmit control signals through the control transmission lines, depending on the transmit clock. The receiver includes a receive clock generator that generates a read clock from the control signals; and a data receiving unit that receives the data signal through the data signal transmission line, depending on the read clock.

Abstract: Embodiments of the present invention may provide for independent setting of jitter tolerance and jitter transfer levels, and reduced jitter generation of a data transmission device, such as a clock and data recovery (CDR) circuit or the like. An architecture may provide for reconfigurability of a circuit for use in various applications. The architecture may include a multi-loop structure, such as a tri-loop structure.