Aspects of the disclosure provide a receiver for receiving data over a wired communication channel. The receiver includes an analog front end circuit, a pulse generation circuit and a voltage-controlled oscillator (VCO). The analog front end circuit receives an analog signal carrying data over the wired communication channel, and outputs a data signal with data bit transitions between voltage levels. The pulse generation circuit generates a pulse signal in response to the data bit transitions in the data signal. The voltage-controlled oscillator (VCO) generates an oscillation signal for providing sampling clocks for the data signal. The voltage-controlled oscillator aligns transitions in the oscillation signal to the pulse signal by forcing the oscillation signal to transit voltage levels in response to a pulse in the pulse signal.

A receiver device comprises one or more differential receivers configured to respectively output single ended signals, one or more delay compensation circuitries configured to delay the single ended signals, clock recovery circuitry configured to generate a recovered clock signal based on a compensated single ended signals respectively outputted from the delay compensation circuitries, and one or more latch circuitries configured to respectively latch the compensated single ended signals in synchronization with the recovered clock signal.

A short-reach data link receiver includes an edge detector configured to generate a pulse on an edge of a data input, a first clock-data recovery path coupled to an output of the edge detector for recovering a clock and data from the output of the edge detector, a second clock-data recovery path coupled to the output of the edge detector for recovering the clock and data from the output of the edge detector, and a controller configured to alternate between the first and second clock-data recovery paths to recover the clock and data using one of the paths while calibrating the other path. The controller may swap the paths whenever calibration of one path is completed. That may include beginning calibration of the next path immediately after swapping of the paths. Alternatively, power consumption may be reduced by delaying calibration of the next path after swapping of the paths.

Methods, apparatus, and systems for communication over a multi-wire, multi-phase interface are disclosed. A clock recovery method includes generating a combination signal that includes transition pulses, each transition pulse being generated responsive to a transition in a difference signal representative of a difference in signaling state of a pair of wires in a three-wire bus. The combination signal is provided to a logic circuit that is configured to provide a clock signal as its output, where pulses in the combination signal cause the clock signal to be driven to a first state. The logic circuit receives a reset signal that is derived from the clock signal by delaying transitions to the first state while passing transitions from the first state without added delay. The clock signal is driven from the first state after passing a transition of the clock signal to the first state.

A clock-data recovery circuit includes a variable data path delay, an injection-locked oscillator having a free-running frequency, and circuitry for adjusting at least one of the variable data path delay and the free-running frequency, including a counter configured to count repetitions of a bit value in an input data signal, and further being configured to, on occurrence of a first data pattern in the input data signal, indicative of saturation of inter-symbol interference, measure the input data signal at a first clock edge to determine a first data phase measurement value, measure the input data signal at clock centers immediately preceding and immediately following the first clock edge to determine second and third data phase measurement values, and based on first predetermined relationships among the first, second and third data phase measurement values, adjust the variable data path.

A signaling system is described. The signaling system comprises a transmit device, a receive device including a partial response receive circuit, and a signaling path coupling the transmit device and the receive device. The receive device observes an equalized signal from the signaling path, and includes circuitry to use feedback from the most recent previously resolved symbol to sample a currently incoming symbol. The transmit device equalizes transmit data to transmit the equalized signal, by applying weighting based on one or more data values not associated with the most recent previously resolved symbol value.

An asynchronous data capture device comprises an edge spread detector circuit, a clock generator, and a data sampling circuit. The edge spread detector circuit uses a first clock frequency that is a multiple of a second clock frequency, identifies transitions in a data stream transmitted to the device at the second clock frequency, and determines a sampling point based on the identified transitions. The clock generator adjusts a phase offset based on the sampling point and generates a clock signal having the second clock frequency and the adjusted phase offset. The data sampling circuit uses the second clock frequency and samples the data stream at the sampling point. In some implementations, the edge spread detector determines a sampling point that is isolated from the identified transitions, and the clock generator adjusts the phase offset to cause a rising edge at the sampling point.

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.

An asynchronous data capture device comprises an edge spread detector circuit, a clock generator, and a data sampling circuit. The edge spread detector circuit uses a first clock frequency that is a multiple of a second clock frequency, identifies transitions in a data stream transmitted to the device at the second clock frequency, and determines a sampling point based on the identified transitions. The clock generator adjusts a phase offset based on the sampling point and generates a clock signal having the second clock frequency and the adjusted phase offset. The data sampling circuit uses the second clock frequency and samples the data stream at the sampling point. In some implementations, the edge spread detector determines a sampling point that is isolated from the identified transitions, and the clock generator adjusts the phase offset to cause a rising edge at the sampling point.

A short-reach data link receiver includes an edge detector configured to generate a pulse on an edge of a data input, a first clock-data recovery path coupled to an output of the edge detector for recovering a clock and data from the output of the edge detector, a second clock-data recovery path coupled to the output of the edge detector for recovering the clock and data from the output of the edge detector, and a controller configured to alternate between the first and second clock-data recovery paths to recover the clock and data using one of the paths while calibrating the other path. The controller may swap the paths whenever calibration of one path is completed. That may include beginning calibration of the next path immediately after swapping of the paths. Alternatively, power consumption may be reduced by delaying calibration of the next path after swapping of the paths.