A method for checking a message in a communication system, in which multiple users are connected to a communication medium that includes two signal lines and exchange messages via same. A time difference between points in time of reception of a message that is sent on the communication medium is ascertained at two different, predefined positions on the communication medium, and based on a comparison of the time difference to at least one reference time difference, it is determined whether the message originates from a verified user. During the ascertainment of the time difference at the two positions, in each case a difference signal is formed from signals that have resulted on the two signal lines due to the message.

A phase correcting device includes a local oscillator that includes an all digital phase-locked loop configured to output a local oscillation signal, a first phase detector configured to detect a phase of the local oscillation signal to output the phase of the local oscillation signal, a reference phase device configured to generate a quasi-reference phase corresponding to a reference phase of the local oscillation signal to output the quasi-reference phase, based on a reference clock, a second phase detector configured to detect a fluctuation amount of a phase of the local oscillator, based on the phase detected by the first phase detector and the quasi-reference phase, and a correction circuit configured to correct the phase of the inputted signal by using a detection result of the second phase detector.

A clock stretcher includes a DLL that derives delayed versions of an input clock signal, and a combiner that cyclically selects the delayed versions to generate a modified clock signal. The DLL has a phase error because of its finite bandwidth. The clock stretcher measures the phase error and corrects for a glitch in the modified clock signal by using the phase error when phase selection wraparound occurs. The clock stretcher may operate from a power supply that has droops, without intervening voltage regulation.

A clock stretcher includes a DLL that derives delayed versions of an input clock signal, and a combiner that cyclically selects the delayed versions to generate a modified clock signal. The DLL has a phase error because of its finite bandwidth. The clock stretcher measures the phase error and corrects for a glitch in the modified clock signal by using the phase error when phase selection wraparound occurs. The clock stretcher may operate from a power supply that has droops, without intervening voltage regulation.

An electronic circuit includes a first pin corresponding to a reference signal and a second pin corresponding to an external resistor, the external resistor being connected on a first side to the second pin and connected on a second side to ground. The apparatus also includes a first oscillator having a first frequency loop configured to: receive, via the first pin, the reference signal; receive, via the second pin, a current associated with voltage applied to the external resistor; and lock a first frequency output at a frequency associated with the reference signal. The apparatus also includes a second oscillator having a second frequency loop configured to: receive the first frequency output; scale the frequency of the first frequency output; and lock a second frequency output at the scaled frequency of the first frequency output.

A phase and frequency detector receives a reference clock signal with a period error and receives a feedback clock signal from a feedback divider. The feedback divider circuit divides a clock signal from a voltage controlled oscillator. The feedback divider divides by different divide values during odd and even cycles of the reference clock signal to cause the feedback clock signal to have a period error that substantially matches the period error of the reference clock signal. The divider values supplied to the feedback divider are determined, at least in part, by the period error of the reference clock signal.

Provided are a random number generating device and a method of operating the same. The random number generating device includes a source detector, a pulse generator, a counter, and a verification circuit. The source detector detects particles emitted from a source to generate a detection signal. The pulse generator generates pulses corresponding to the detected particles, based on the detection signal. The counter measures time intervals among the pulses and generates binary count values respectively corresponding to the time intervals. The verification circuit determines an output of the binary count values, based on the number of 0 values and the number of 1 values included in the binary count values.

Techniques for reliable clock speed change and associated circuits and methods are disclosed. Internal voltage supplies of semiconductor devices may include oscillators and charge pump circuits. The oscillator may include at least two clock paths for generating clock signals having different clock frequencies, which can be provided to the charge pump circuit. Further, the oscillator may generate a reset signal configured to activate one clock path over the other (e.g., changing clock speeds). In some embodiments, the oscillator includes a flip-flop to align the reset signal with respect to an edge of an input clock signal supplied to the oscillator such that unintentional (undesired, unexpected) features in the output signal of the oscillator can be avoided when the oscillator changes clock speeds.

An apparatus includes a digitally controlled oscillator (DCO), which includes an inductor coupled in series with a first capacitor. The DCO further includes a second capacitor coupled in parallel with the series-coupled inductor and first capacitor, a first inverter coupled in parallel with the second capacitor, and a second inverter coupled back-to-back to the first inverter. The DCO further includes a digital-to-analog-converter (DAC) to vary a capacitance of the first capacitor.

A phase correcting device includes a local oscillator configured to give a local oscillation signal to a device configured to detect a phase of an inputted signal, a first phase detector configured to detect a phase of the local oscillation signal to output the phase of the local oscillation signal, a reference phase device configured to generate a quasi-reference phase corresponding to a reference phase of the local oscillation signal at a time of an initial setting of the local oscillator to output the quasi-reference phase, based on a reference clock, a second phase detector configured to detect, a fluctuation amount of a phase of the local oscillator, based on the phase detected by the first phase detector and the quasi-reference phase, and a correction circuit configured to correct the phase of the inputted signal by using a detection result of the second phase detector.