A method and an apparatus are provided. The apparatus may include a clock recovery circuit having a plurality of input latches configured to assume a first state when a first pulse is received in one or more of a plurality of input signals, combinational logic configured to provide a second pulse response to the first pulse, a delay circuit configured to produce a third pulse on a receive clock that is delayed with respect to the second pulse, a plurality of output flip-flops configured to capture the first state when triggered by the third pulse. The first state may identify which of the plurality of input signals received input pulses.

An electronic system includes transmitting circuitry of a first clock domain and receiving circuitry of a second domain. The transmitting circuitry re-times a digital input signal with rising edges of a clocking signal of the first clock domain when a phase of the clocking signal of the first clock domain leads a phase of a clocking signal associated with the digital input signal. Otherwise, the transmitting circuitry re-times the digital input signal with falling edges of the clocking signal of the first clock domain when the phase of the clocking signal of the first clock domain does not lead the phase of the clocking signal associated with a digital input signal. The receiving circuitry receives the re-timed digital input signal from the transmitting circuitry. Thereafter, the receiving circuitry re-times the re-timed digital input signal with rising edges of a phase of a clocking signal associated with the re-timed digital input signal when the phase of the clocking signal associated with the re-timed digital input signal leads a phase of a clocking signal of the second clock domain. Otherwise, the receiving circuitry re-times the re-timed digital input signal with falling edges of the phase of a clocking signal associated with the re-timed digital input signal when the phase of the clocking signal associated with the re-timed digital input signal does not lead the phase of a clocking signal of the second clock domain.

An electronic system includes transmitting circuitry of a first clock domain and receiving circuitry of a second domain. The transmitting circuitry re-times a digital input signal with rising edges of a clocking signal of the first clock domain when a phase of the clocking signal of the first clock domain leads a phase of a clocking signal associated with the digital input signal. Otherwise, the transmitting circuitry re-times the digital input signal with falling edges of the clocking signal of the first clock domain when the phase of the clocking signal of the first clock domain does not lead the phase of the clocking signal associated with a digital input signal. The receiving circuitry receives the re-timed digital input signal from the transmitting circuitry. Thereafter, the receiving circuitry re-times the re-timed digital input signal with rising edges of a phase of a clocking signal associated with the re-timed digital input signal when the phase of the clocking signal associated with the re-timed digital input signal leads a phase of a clocking signal of the second clock domain. Otherwise, the receiving circuitry re-times the re-timed digital input signal with falling edges of the phase of a clocking signal associated with the re-timed digital input signal when the phase of the clocking signal associated with the re-timed digital input signal does not lead the phase of a clocking signal of the second clock domain.

A clock data recovery circuit includes a deglitch filter circuit and a timer circuit. The deglitch filter circuit is configured to remove pulses of less than a particular duration from a data signal to produce a deglitched data signal. The timer circuit is coupled to the deglitch filter, and is configured to compare a duration of a pulse of the deglitched data signal to a threshold duration, and identify the pulse as representing a logic one based on the duration of the pulse exceeding the threshold duration.

Technology for a phase detector is described. The phase detector can include a reference clock. The phase detector can include a feedback clock. The phase detector can include a first latch operable to set a first latch output depending on a lead-lag status between the reference clock and the feedback clock. The phase detector can include a second latch that loads the lead-lag status when the reference clock and the feedback clock produce clock signals in a high state. The phase detector can include a third latch that loads the lead-lag status from the second latch when the reference clock and the feedback clock produce clock signals in a low state.

A device includes a recovery unit that separates recovery data and a recovery clock from input data, a first detection unit that detects a timing at which a phase difference between a generated processing clock and the recovery clock is zero, a second detection unit that detects a synchronization code included in the recovery data using the recovery clock, and a calculation unit that calculates a phase difference between the synchronization code and the processing clock using a ratio between a first number of clock generation times of the processing clock in a period from a first timing at which the detected phase difference is zero to a second timing at which the phase difference is subsequently zero, and a second number of clock generation times of the processing clock in a period from the first timing to a third timing in which the synchronization code is detected.

Methods and systems are described for receiving a signal to be sampled and responsively generating, at a pair of common nodes, a differential current representative of the received signal, receiving a plurality of sampling interval signals, each sampling interval signal received at a corresponding sampling phase of a plurality of sampling phases, for each sampling phase, pre-charging a corresponding pair of output nodes using a pre-charging FET pair receiving the sampling interval signal, forming a differential output voltage by discharging the corresponding pair of output nodes via a discharging FET pair connected to the pair of common nodes, the FET pair receiving the sampling interval signal and selectively enabling the differential current to discharge the corresponding pair of output nodes, and latching the differential output voltage.

Technology for a phase detector is described. The phase detector can include a reference clock. The phase detector can include a feedback clock. The phase detector can include a first latch operable to set a first latch output depending on a lead-lag status between the reference clock and the feedback clock. The phase detector can include a second latch that loads the lead-lag status when the reference clock and the feedback clock produce clock signals in a high state. The phase detector can include a third latch that loads the lead-lag status from the second latch when the reference clock and the feedback clock produce clock signals in a low state.

According to one embodiment, an electronic circuit is described comprising a first clock domain configured to operate according to a first clock signal, a second clock domain configured to operate according to a second clock signal different from the first clock signal, an encoding circuit, in the first clock domain, configured to encode data to be transmitted from the first clock domain to the second clock domain into codewords and configured to supply the codewords to an interface between the first clock domain and the second clock domain and a reception circuit, in the second clock domain, configured to receive data words from the interface, to decode valid codewords and to discard invalid codewords.

A clock generation circuit may include a reference clock generator configured to generate a pair of first reference clocks in an offset code generation mode, a correction code generator configured to generate a reference correction code according to a duty detection signal based on a phase difference between the pair of first reference clocks, and an offset code generator configured to generate an offset code based on the reference correction code and a preset reference code.