A buffer circuit, a frequency dividing circuit, and a communications device are disclosed. The buffer circuit includes a buffer, a first control circuit, and a second control circuit. The buffer is coupled to a frequency divider, and the buffer is configured to receive a first signal output by the frequency divider, and output a fourth signal by using an output terminal of the buffer circuit when driven by the first signal, where the first signal is obtained by the frequency divider by performing frequency division on a group of differential signals, and the differential signals include a second signal and a third signal. The first control circuit is configured to perform delay control on a rising edge of the fourth signal based on the second signal. The second control circuit is configured to perform delay control on a falling edge of the fourth signal based on the third signal.

A method for evaluating performance of a sequential logic element includes: inputting a preset clock signal and a data signal to a sequential logic element to be tested; decrementing a setup time of the sequential logic element from a first preset value to a second preset value based on a preset decrement step, where the first preset value is determined by a setup time when the sequential logic element to be tested outputs a target sampled value, and the second preset value is determined by a setup time when the sequential logic element outputs a reverse value of the target sampled value; and determining an evaluation parameter of the sequential logic element based on a sampled value output by the sequential logic element after each decrement of the setup time, and evaluating performance of the sequential logic element based on the evaluation parameter of the sequential logic element to be tested.

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.

Power demands of a computing system, such as a network device and/or a component thereof, are stabilized by introducing a programmable delay into identical or substantially similar subsystems within an integrated circuit. Each subsystem reads a potentially different delay value from an associated storage, memory, or input, and waits for some time indicated by the delay value before beginning execution. For example, in a group of identical subsystems that process data concurrently, some or all of the subsystems begin processing their respective data after a different amount of delay, thus staggering their respective executions and lowering the risk of aligned edges when some or all of the subsystems concurrently step their power demands up or down. This, in turn, reduces peak power and voltage. In an embodiment, rather than being fixed at the design stage, each subsystem's delay value is programmable at some point after fabrication.

Disclosed is a system where indicators of the relative phase differences between combinations of clocks in a multi-phase clock system are developed and/or measured. These indicators convey information regarding which phase difference between a given pair of the clocks is greater than (or less than) the phase difference between another pair of the clocks. This information is used to sort/rank/order phase differences between the various combinations of pairs of clocks according to their phase differences. This ranking is used to select the pair of clocks to be adjusted.

A clock sweeping system includes multiple delay elements and a selection circuit. The delay elements are configured to generate multiple delayed clock signals. Each delay element is configured to receive an input signal and delay the input signal to generate a corresponding first delayed clock signal. The input signal is one of a first clock signal, a second clock signal, and a corresponding output signal generated by a previous delay element. The selection circuit is configured to select and output, based on a first select signal for a plurality of times, a corresponding second delayed clock signal as a first output clock signal. The selection circuit is further configured to select and output, based on a second select signal, one of the first and second clock signals as a second output clock signal. The first output clock signal is asynchronous with respect to the second output clock signal.

Aspects of the technology described herein relate to ultrasound device circuitry as may form part of a single substrate ultrasound device having integrated ultrasonic transducers. The ultrasound device circuitry may facilitate the generation of ultrasound waveforms in a manner that is power- and data-efficient.

A driving circuit, including: a pull-up transistor and a pull-down transistor, where a first terminal of the pull-up transistor is connected with a power source, a second terminal of the pull-up transistor is connected with a first terminal of the pull-down transistor to together output a driving signal, and a second terminal of the pull-down transistor is connected to ground; and a control circuit connected with a control terminal of the pull-up transistor and/or the pull-down transistor respectively and configured to control the on or off switching of the pull-up transistor and/or the pull-down transistor so as to change the driving signal. The pull-up transistor and the pull-down transistor are not switched on at the same time under the control of the control circuit.

In certain aspects, a digital circuit comprises a delay line to generate a plurality of delayed versions of an input clock. The digital circuit also comprises selection circuitry to provide a selected one of the plurality of delayed versions of the input clock based on a clock selection signal and feedback circuitry to generate the clock selection signal based on the selected one of the plurality of delayed versions of the input clock and based on the input clock. The clock selection signal is further used for selecting and generating other clocks and/or for variation control.

A circuit system is disclosed. In one example, the circuit system includes a clock tree circuit with multiple lanes to which a clock signal is distributed. A duty correction circuit is provided for each of the multiple lanes, and corrects a duty ratio of the clock signal. A clock gating circuit group has a clock gating circuit for each of the multiple lanes and receives, as input, the clock signal from the duty correction circuit. The clock gating circuit group starts output of the clock signal from each of a plurality of the clock gating circuits in a predetermined period. A variable delay circuit is provided in association with each of a plurality of the duty correction circuits and is capable of changing a delay time of a control signal that controls a timing of starting output of the clock signal from the clock gating circuit.