A four-phase (or multi-phase) generation circuit, related method of operation, and transceivers or other systems utilizing such a circuit, are disclosed herein. In one example embodiment, the circuit includes two input ports respectively configured to receive positive and negative differential input signals, and four output ports respectively configured to output first, second, third and fourth output signals, respectively, the second, third, and fourth output signals being respectively phase-shifted relative to the first output signal by or substantially by 90, 180, and 270 degrees. Also, the circuit includes four SR latches respectively including output terminals that are respectively coupled to the respective output ports. Further, the circuit includes two tunable delay circuits respectively coupled at least indirectly between the input ports and latches, and two comparison circuits configured to output respective feedback signals. The latches receive two delayed input signals provided by the delay circuits based upon the feedback signals.

A test method for a delay circuit and a test circuitry are provided. The test circuitry incudes the delay circuit that essentially includes multiple serially connected logic gates, a clock pulse generator at an input end of the delay circuit for generating one or more cycles of clock signals, and a counter at an output end of the delay circuit for counting the clock signals passing through the delay circuit. The test circuitry implements a test mode by switching lines to the clock pulse generator and the counter. The test circuitry relies on a comparison result of a counting result made by the counter and a number of the cycles of the clock signals to test any failure of the delay circuit.

In described examples, an electronic circuit for determining a phase difference between a first clock signal and a second clock signal includes a timer circuit, circuitry for generating a selectively delayed transition of the second clock signal, and phase determination circuitry. The timer circuit produces an elapsed time between a transition of the first clock signal and the selectively delayed transition of the second clock signal. The circuitry for generating the selectively delayed transition of the second clock signal generates the selectively delayed transition in response to a random selection of a respective output from a plurality of second clock signal delay stages. The phase determination circuitry provides the phase difference in response to the elapsed time and the random selection of a respective output from a plurality of second clock signal delay stages.

A method for operating a data interface circuit whereby calibration adjustments for data bit capture are made without disturbing normal system operation includes initially establishing, using a first calibration method where a data bit pattern received by the data interface circuit is predictable, an optimal sampling point for sampling data bits received by the data interface circuit, and during a normal system operation and without disturbing the normal system operation, performing a second calibration method where the data bit pattern received by the data interface circuit is unpredictable. The second calibration method determines an amount of a timing drift for received data bit edge transitions and adjusts the optimal timing point determined by the first calibration method to create a revised optimal timing point. The second calibration method samples fringe timing points associated with the transition edges of a data bit.

A temperature delay device includes a first thermal sensor, a second thermal sensor, an inverter, and a latch circuit. The first thermal sensor is configured to measure a first temperature of a chip to output a first input signal. The second thermal sensor is configured to measure a second temperature of the chip to output a second input signal. The inverter is coupled to the first thermal sensor, and is configured to reverse the first input signal so as to output a third input signal. The latch circuit is coupled to the inverter and the second thermal sensor, and is configured to output an output signal according to the second input signal and the third input signal. The first temperature is different from the second temperature.

Disclosed herein is a programmable delay circuit for providing an adjustable delay for a signal transmitted from an input node to an output node. The adjustable delay circuit includes an input node; an output node; and a pair of inverter circuits coupled in series between the input node and the output node, wherein the pair of inverter circuits is configured to provide an adjustable delay for a signal transmitted from the input node to the output node. At least one inverter circuit of the pair of inverter circuits includes a state-programmable memory element that allows the pair of inverter circuits to be configurable between a first delay mode or a second delay mode.

A serial bus re-driver circuit includes an edge detector circuit and a booster circuit. The edge detector circuit is configured to detect a transition of serial bus signal. The booster circuit is coupled to the edge detector circuit, and is configured to switch current to the serial bus signal. The booster circuit includes a leading edge boost pulse generation circuit and a trailing edge boost pulse generation circuit. The leading edge boost pulse generation circuit is configured to switch a first current pulse to the serial bus signal at the transition of the serial bus signal. The trailing edge boost pulse generation circuit is configured to switch a second current pulse to the serial bus signal. The second current pulse is shorter than the first current pulse.

An Inter-IC interface with a glitch filter including at least two cascaded RC filters configured to compensate a signal skew of the data or clock signal received from a data communication or clock signal line, feedback switches configured to pull up or pull down a voltage at an output node of each of the at least two cascaded RC filters, and feedforward transistors configured to condition a respective switch to the feedback switches to accelerate the pull up or the pull down.

Methods, systems, and devices for delay adjustment circuits are described. Amplifiers (e.g., differential amplifiers) may act like variable capacitors (e.g., due to the Miller-effect) to control delays of signals between buffer (e.g., re-driver) stages. The gains of the amplifiers may be adjusted by adjusting the currents through the amplifiers, which may change the apparent capacitances seen by the signal line (due to the Miller-effect). The capacitance of each amplifier may be the intrinsic capacitance of input transistors that make up the amplifier, or may be a discrete capacitor. In some examples, two differential stages may be inserted on a four-phase clocking system (e.g., one on 0 and 180 phases, the other on 90 and 270 phases), and may be controlled differentially to control phase-to-phase delay.

Embodiments relate to a circuit implementation for controlling a delay of a clock signal. The clock delay control circuit includes a sensing circuit and a phase interpolator controlled by the sensing circuit. The sensing circuit generates a first control signal that increases when a level of a supply voltage increases, and decreases when the level of the supply voltage decreases. Moreover, the sensing circuit generates a second control signal that decreases when the level of the supply voltage increases, and increases when the level of the supply voltage decreases. The phase interpolator includes multiple paths, each having a different propagation delay. The coupling between each path and the output node of the phase interpolator is controlled by the control signals generated by the sensing circuit.