A shift register circuit including a flip-flop chain and a control circuit is provided. The flip-flop chain is configured to receive an input signal and output an output signal. The control circuit is coupled to the flip-flop chain. The control circuit is configured to receive the input signal and the output signal and output a control signal to activate the flip-flop chain according to edge transitions of the input signal and the output signal. In addition, a method for controlling a shift register circuit is also provided.

A register circuit for which an initial value can be changed without using a flip-flop including both a set terminal and a reset terminal is provided. The register circuit includes an initial value wiring line, a write signal terminal, a clock signal terminal, a first flip-flop, an output control circuit, a second flip-flop, and a selector.

A counting device, including multiple counting circuit stages and a first logic operation circuit, is provided. The counting circuit stages are serially coupled in sequence. A first counting circuit stage performs a counting action according to a first clock signal and generates a first counting result. Second to Nth counting circuit stages perform counting actions according to a second clock signal, where N is a positive integer greater than 2. The first logic operation circuit provides the first counting result to be the second clock signal according to an indication signal.

An electronic latch circuit (100) and a multi-phase signal generator (300) are disclosed. The electronic latch circuit (100) comprises an output circuit (105) comprising a first output (X, 106), a second output (Y, 107) and a third output (Z, 108). The electronic latch circuit (100) further comprises an input circuit (101) comprising a first input (A, 102), a second input (B, 103) and a clock signal input (CLK, 104). The electronic latch circuit (100) is configured to change state based on input signals at the inputs (A, B, CLK) of the input circuit (101) and a present state of the output circuit (105). The multi-phase signal generator (300) comprises a plurality N of the electronic latch circuit (100) for generating N phase signals with individual phases. The plurality N of the electronic latch circuit (100) are cascaded with each other.

The present disclosure provides a low-jitter frequency division clock circuit, including: a clock control signal generation circuit, to generate clock signals having different phases; a low-level narrow pulse width clock control signal generation circuit, to generate a low-level narrow pulse width clock control signal; a high-level narrow pulse width clock control signal generation circuit, to generate a high-level narrow pulse width clock control signal; and a frequency division clock generation circuit, to generate a frequency division clock signal according to low-level narrow pulse width clock control signal and high-level narrow pulse width clock control signal. The delay from a clock input end to an output end of low-jitter frequency division clock circuit is up to three logic gates. Compared with traditional divide-by-2 frequency division clock circuits based on D-flip-flop, the low-jitter frequency division clock circuit of the present disclosure has fewer logic gates, a shorter delay, and lower jitter.

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.

The present disclosure provides a low-jitter frequency division clock circuit, including: a clock control signal generation circuit, to generate clock signals having different phases; a low-level narrow pulse width clock control signal generation circuit, to generate a low-level narrow pulse width clock control signal; a high-level narrow pulse width clock control signal generation circuit, to generate a high-level narrow pulse width clock control signal; and a frequency division clock generation circuit, to generate a frequency division clock signal according to low-level narrow pulse width clock control signal and high-level narrow pulse width clock control signal. The delay from a clock input end to an output end of low-jitter frequency division clock circuit is up to three logic gates. Compared with traditional divide-by-2 frequency division clock circuits based on D-flip-flop, the low-jitter frequency division clock circuit of the present disclosure has fewer logic gates, a shorter delay, and lower jitter.

A frequency divider is provided that includes a plurality of latches for dividing an input clock according to an integer frequency divisor N of three or greater. Each latch is coupled to a corresponding pair of logic gates. For each latch, one of the logic gates in the corresponding pair controls a setting of the latch whereas a remaining one of the logic gates in the corresponding pair controls a resetting of the latch. Each latch outputs a pair of overlapping clock signals that are divided in frequency with respect to the input clock and have a 50% duty cycle. Each logic gate processes a pair of the overlapping clock signal and the input clock signal to provide a non-overlapping clock signal of the same frequency of the overlapping clock signals but have a (50/N) % duty cycle.

A frequency divider is provided that includes a plurality of latches for dividing an input clock according to an integer frequency divisor N of three or greater. Each latch is coupled to a corresponding pair of logic gates. For each latch, one of the logic gates in the corresponding pair controls a setting of the latch whereas a remaining one of the logic gates in the corresponding pair controls a resetting of the latch. Each latch outputs a pair of overlapping clock signals that are divided in frequency with respect to the input clock and have a 50% duty cycle. Each logic gate processes a pair of the overlapping clock signal and the input clock signal to provide a non-overlapping clock signal of the same frequency of the overlapping clock signals but have a (50/N) % duty cycle.

An electronic latch circuit, a 4-phase signal generator, a multi-stage frequency divider and a poly-phase signal generator are disclosed. The electronic latch circuit comprises an output circuit comprising a first output and a second output. The electronic latch circuit further comprises an input circuit comprising a first input, a second input and a clock signal input. The electronic latch circuit is configured to change state based on the input signals' level at the inputs of the input circuit and a present state of the output circuit. The 4-phase signal generator is built with two electronic latch circuits. The multi-stage frequency dividers and poly-phase signal generators comprise a plurality of the electronic latch circuits and 4-phase signal generators.