Patent classifications
H04L7/0337
Signaling system with adaptive timing calibration
A signaling system is disclosed. The signaling system includes a first integrated circuit (IC) chip to receive a data signal and a strobe signal. The first IC includes circuitry to sample the data signal at times indicated by the strobe signal to generate phase error information and circuitry to output the phase error information from the first IC device. The system further includes a signaling link and a second IC chip coupled to the first IC chip via the signaling link to output the data signal and the strobe signal to the first IC chip. The second IC chip includes delay circuitry to generate the strobe signal by delaying an aperiodic timing signal for a first time interval and timing control circuitry to receive the phase error information from the first IC chip and adjust the first time interval in accordance with the phase error information.
Techniques for ephemeral messaging with a message queue
Techniques for ephemeral message are described. In one embodiment, an apparatus may comprise a delayed-action worker module operative to wake according to a wake timer; determine a current update object for a delayed-action cursor for a recipient update queue for a messaging system, the delayed-action cursor associated with an action delay for the recipient update queue; determine a delayed-action activity for the current update object; perform the delay-action activity for the current update object; determine a next update object for the delayed-action cursor for the recipient update queue; and determine a next wake timer for the delayed-action worker module based on the action delay and a creation time for the next update object. Other embodiments are described and claimed.
EFFICIENT PHASE CALIBRATION METHODS AND SYSTEMS FOR SERIAL INTERFACES
A phase calibration method includes sweeping phase codes applicable to a serial clock signal, identifying a first, a second, a third, and a fourth phase code, wherein the first phase code causes zero plus a first threshold number of bits extracted from the serial data signal to be a particular value, wherein the second phase code causes all minus a second threshold number of bits extracted from the serial data signal to be the particular value, wherein the third phase code causes all minus a third threshold number of bits extracted from the serial data signal to be the particular value, wherein the fourth phase code causes zero plus a fourth threshold number of bits extracted from the serial data signal to be the particular value, determining an average phase code based on the identified phase codes.
RECEIVER INCLUDING A MULTI-RATE EQUALIZER
A receiver includes an equalization circuit configured to output a data sample signal and an edge sample signal by sampling a data input signal according to clock signal, and to perform an equalization operation according to the data sample signal and the edge sample signal; and a clock gate circuit configured to select the clock signals from among a plurality of multi-phase clock signals according to a selection signal.
Phase interpolation based clock data recovery circuit and communication device including the same
A clock data recovery circuit includes a phase locked loop (PLL), a code signal generator, and a clock and data generator. The PLL generates a plurality of reference clock signals of which frequencies are modulated. Each of the plurality of reference clock signals has a first profile that is periodically fluctuated. The code signal generator generates a first compensation code signal. The first compensation code signal has a second profile that is periodically fluctuated and is different from the first profile. The clock and data generator generates a recovered data signal by sampling an input data signal based on a clock signal, compensates a frequency modulation on the plurality of reference clock signals based on the first compensation code signal, and includes a phase interpolator that generates the clock signal based on the plurality of reference clock signals and the first compensation code signal.
NETWORK TRANSCEIVER WITH VGA CHANNEL SPECIFIC EQUALIZATION
A network transceiver device is provided, including at least two variable gain amplifiers (VGAs), and at least two sets of analog digital converters (ADCs), each set including ADCs coupled to an output of one of the VGAs, the sets being arranged in VGA-specific channels. The device includes a plurality of feed-forward equalizers (FFEs), each FFE being coupled to receive an output of one of the ADCs in one of the VGA-specific channels. Each FFE is configured to adaptively equalize the output received from the ADCs utilizing a first equalization coefficient subset with coefficient values that are common to all FFEs, and a second equalization coefficient subset that is channel specific and that has a first set of coefficient values for a first VGA-specific channel and a second set of coefficient values for a second VGA-specific channel, the sets of coefficient values being computed independently.
HIGH-SPEED SIGNALING SYSTEMS WITH ADAPTABLE PRE-EMPHASIS AND EQUALIZATION
A signaling system includes a pre-emphasizing transmitter and an equalizing receiver coupled to one another via a high-speed signal path. The receiver measures the quality of data conveyed from the transmitter. A controller uses this information and other information to adaptively establish appropriate transmit pre-emphasis and receive equalization settings, e.g. to select the lowest power setting for which the signaling system provides some minimum communication bandwidth without exceeding a desired bit-error rate.
EFFICIENT FREQUENCY DETECTORS FOR CLOCK AND DATA RECOVERY CIRCUITS
A system and method for a frequency detector circuit includes: a transition detector configured to receive a data input and provide a first edge output based on transitions in the data input; a first circuit configured to generate a second edge output; a second circuit configured to generate a third edge output; and a combinational logic configured to output an UP output when at least two of the first edge output, the second edge output, and the third edge output are high and configured to output a DOWN output when the first edge output, the second edge output, and the third edge output are all low.
Phase-aligning multiple synthesizers
Embodiments of the present invention synchronize multiple synthesizers, such as phase-locked loops (PLLs), in a manner that does not require communication or coordination between the synthesizers. Specifically, each synthesizer is part of a synthesizer circuit that includes a synthesizer (e.g., a PLL), a phase measurement circuit, and a synchronization circuit. A common reference signal (e.g., an alternating clock signal) is provided to the synthesizer circuits. In one exemplary embodiment, in each synthesizer circuit, the phase measurement circuit measures a phase difference between the reference signal and a corresponding output of the synthesizer, and the synchronization circuit adjusts the synthesizer operation based on the measured phase difference in such a way that all of the synthesizers operate in-phase with one another relative to the common reference signal, without having any communication or coordination between the two synthesizer circuits other than provision of the common reference signal.
EQUALIZER CIRCUIT, METHOD FOR SAMPLING DATA AND MEMORY
An equalizer circuit, a method for sampling data and a memory are provided. The equalizer circuit includes a first input buffer circuit, a second input buffer circuit and a selecting and sampling circuit. The first input buffer circuit and the second input buffer circuit are respectively connected with the selecting and sampling circuit, and reference voltages used in the first input buffer circuit and the second input buffer circuit are different from each other. The selecting and sampling circuit selects to perform data sampling on a data signal outputted by the first input buffer circuit or the second input buffer circuit according to data outputted previously by the equalizer circuit, and takes sampled data as data outputted currently by the equalizer circuit.