Systems and methods for clock recovery are disclosed. The method comprises generating, by a first dynamic phase interpolator, a first center clock signal, and generating, by a second dynamic phase interpolator, a second center clock signal. The method further comprises outputting, by a static phase interpolator, an edge clock signal based on the first and second center clock signals.

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.

A source synchronous data transmission system includes a data transmitting device and a data receiving device. A dedicated data line carries a data signal from the data transmission device to the data receiving device. A dedicated clock line carries a modulated clock signal from the data transmission device to the data receiving device. The data transmission device includes a clock data driver configured to encode data into the modulated clock signal by modulating an amplitude of the modulated clock signal. Thus, the clock line of the source synchronous data transmission system carries the clock signal and additional data.

A communication device according to the disclosure includes: a signal generator that generates, on the basis of the first signal received from a communication partner through a coil, a second signal that synchronizes with the first signal; a first modulator configured to be able to modulate the first signal on the basis of the second signal; a second modulator configured to be able to modulate the first signal; and a communication controller that selects, on the basis of the first signal, whichever modulator is to be operated, from the first modulator and the second modulator.

A master device communicates with a slave device through an asynchronous serial communications link. The master device includes a single pad configured to communicate a command frame including an address and a data frame including data with the slave device via a single wire; and a processing circuit configured to generate an oversampling clock signal from a clock signal, to perform a synchronization process for selecting one of a plurality of clock phases of the oversampling clock signal, and to perform a sampling process for sampling an each bit value included in the data frame transmitted from the slave device using a clock phase at the same position as the clock phase selected during the synchronization process.

A receiver with clock phase calibration. 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.

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.

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.

Disclosed is a card clock recovery system for use in an NFC card transceiver couplable to an NFC reader. The card clock recovery system has: a phase lock loop having: a phase/frequency detector, which is configured to receive a reference signal provided at an RX port of a matching network during a receiving mode of the NFC transceiver or to receive a reference signal provided at the RX port of the matching network during a transmission mode of the NFC transceiver, to receive a loop feedback signal, and to provide a phase error signal that represents a phase difference between the reference signal and the loop feedback signal; a loop filter configured to receive a corrected phase error signal that is derived from the phase error signal, and to provide a filtered corrected phase error signal; a controllable oscillator, which is configured to receive the filtered corrected phase error signal and to provide a controlled frequency output signal, which is provided as the card clock generation control signal to a card clock generation unit of an NFC card transceiver, and as the loop feedback signal, via the loop feedback line, to the phase/frequency detector. The card clock recovery system further has a phase offset correction unit, which is configured to receive the phase error signal provided by the phase/frequency detector and to provide the corrected phase error signal to the loop filter, and which has a phase error sampling unit, a phase offset computation unit, and a phase subtractor unit.

A memory controller includes a clock signal generator generating a clock signal; a first data receiving circuit receiving a serial signal having a plurality of logic values from a memory, using the serial signal to compensate for a phase error of the clock signal, and generating a phase-compensated clock signal as a first clock signal; and at least one second data receiving circuit receiving data from the memory, receiving the first clock signal from the first data receiving circuit, and using the first clock signal to recover the data.