Signal conditioning circuitry includes logic circuitry, a low-pass filter, and comparator circuitry. The logic circuitry is configured to compare a data unit with a preceding data unit, from a sequence of data units, and provide a logic output signal. The low-pass filter is coupled to the logic circuitry, and the low-pass filter is configured to provide a data transition density measurement for the sequence of data units based on the logic output signal. The comparator circuitry is coupled to the low-pass filter, and the comparator circuitry is configured to compare the data transition density measurement to a threshold and, based on the comparison to the threshold, indicate a disruptive pattern in the sequence of data units.

A clock data recovery (CDR) mechanism qualifies symbols received from the data detector prior to using those symbols to compute a timing gradient. The disclosed CDR mechanism analyzes one or more recently received symbols to determine whether the current symbol should be used in computing the time gradient. When configured with a Mueller-Muller phase detector, the timing gradient for the received signal is set to zero if the current symbol is a −2 or a +2 and the previous symbol is non-zero. Otherwise, the Mueller-Muller timing gradient is evaluated in the traditional manner. When configured with a minimum mean-squared error phase detector, the timing gradient for the received signal is set to zero if the previous symbol is non-zero. Otherwise, the minimum mean-squared error timing gradient is evaluated in the traditional manner.

The invention relates to a method for providing a fault-tolerant global time and for the fault-tolerant transport of time-controlled messages in a distributed real-time computer system which comprises external computers and a fault-tolerant message distribution unit, FTMDU. The FTMDU comprises at least four components which supply the global time to the external computers by means of periodic external synchronization messages, wherein the external computers each set their local clock to the received global time, wherein each external sender of a time-controlled message transmits two message copies of the message to be sent via two different communication channels to two different components of the FTMDU at periodic sending times defined a priori in timetables, wherein these two message copies are delivered within the FTMDU via two independent communication paths to those two components of the FTMDU which are connected to an external receiver of the message via communication channels.

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 apparatus comprises circuitry configured for storing a first sequence of values. At the receiver apparatus, a communications signal is received which conveys a second sequence of values, the second sequence of values being related to the first sequence of values. According to some examples, the second sequence of values is identical to the first sequence of values. At the receiver apparatus, P results are calculated from a cross-correlation of the first sequence of values with at least a portion of a representation of the communications signal, where P is a positive integer. According to some examples, P≥2. An estimate of a phase offset of a continuous clock is calculated as a function of the P results. According to some examples, the function is a non-linear function. The estimate of the clock phase offset may be used to achieve clock recovery at the receiver apparatus.

A monitoring device includes: an acquisition unit for acquiring a clock signal output from a communication circuit that outputs the clock signal; and a monitoring unit for analyzing the waveform of the clock signal acquired by the acquisition unit, based on a predetermined reference clock signal having a period equal to or shorter than a period of the clock signal to thereby determine whether or not there is a sign of malfunction in the communication circuit.

A receiver apparatus comprises circuitry configured for storing a first sequence of values. At the receiver apparatus, a communications signal is received which conveys a second sequence of values, the second sequence of values being related to the first sequence of values. According to some examples, the second sequence of values is identical to the first sequence of values. At the receiver apparatus, P results are calculated from a cross-correlation of the first sequence of values with at least a portion of a representation of the communications signal, where P is a positive integer. According to some examples, P≥2. An estimate of a phase offset of a continuous clock is calculated as a function of the P results. According to some examples, the function is a non-linear function. The estimate of the clock phase offset may be used to achieve clock recovery at the receiver apparatus.

An example method of clock and data recovery (CDR) includes adding a pre-defined offset to an output of a phase detector (PD) of a CDR circuit, and loading an accumulator of a frequency loop of the CDR circuit with a pre-defined load value. The method further includes detecting the phase of an incoming signal using a PD, and determining that the CDR has locked onto a real lock point. In some examples, the method further includes determining that the CDR has locked on a real lock point, and, in response to the determination, modifying the pre-defined offset to equal zero.

A communication receiving device includes a clock data recovery circuit, an analog-to-digital converter (ADC), a channel evaluating circuit, a first equalizer, and a selector. The clock data recovery circuit is configured to generate a clock signal according to a first digital signal. The ADC is coupled to the clock data recovery circuit, and configured to convert a first analog signal to a second digital signal according to the clock signal. The channel evaluating circuit is configured to analyze the second digital signal to output a selection signal. The first equalizer is coupled to the ADC, and configured to equalize the second digital signal to generate a third digital signal. The selector is coupled between the first equalizer, the ADC, and the clock data recovery circuit. The selector is configured to output the second digital signal or the third digital signal as the first digital signal according to the selection signal.

Receivers, controller units for receivers and related methods are provided. One receiver includes an adjustable sample provider providing samples of an input signal using an adjustable sample timing and a feedback path providing a feedback signal to the adjustable sample provider based on a timing error. The feedback path includes a loop filter providing sample timing information to the adjustable sample provider and a replacement value provider providing a replacement sample timing information replacing the sample timing information when an input signal does not fulfil a predetermined requirement for a feedback-based sample timing adaptation. The replacement value provider provides the replacement sample timing information considering a timing error information over a longer time period when compared to a time period considered by the loop filter for a provision of the sample timing information.