Clock multiplexer circuitry outputs one of a first or second clock signal. First selection circuitry is connected in series with first counter circuitry. The first selection circuitry and the first counter circuitry receive a first clock signal and a first selection signal. A first control signal is generated based on the first clock signal and the first selection signal. Second selection circuitry is connected in series with second counter circuitry. The second selection circuitry and the second counter circuitry receive a second clock signal and a second selection signal. A second control signal is generated based on the second clock signal and the second selection signal. The output circuitry is connected to the first counter circuitry and the second counter circuitry. The output circuitry outputs one of the first clock signal and the second clock signal based on the first control signal and the second control signal.

Clock multiplexer circuitry outputs one of a first or second clock signal. First selection circuitry is connected in series with first counter circuitry. The first selection circuitry and the first counter circuitry receive a first clock signal and a first selection signal. A first control signal is generated based on the first clock signal and the first selection signal. Second selection circuitry is connected in series with second counter circuitry. The second selection circuitry and the second counter circuitry receive a second clock signal and a second selection signal. A second control signal is generated based on the second clock signal and the second selection signal. The output circuitry is connected to the first counter circuitry and the second counter circuitry. The output circuitry outputs one of the first clock signal and the second clock signal based on the first control signal and the second control signal.

A method can include, in response to a power supply voltage transition, setting a temperature window to a first temperature range by operation of a temperature circuit formed on a semiconductor device. In response to a temperature of the semiconductor device being determined to be outside of the first temperature range, changing the temperature range of the temperature window until the temperature of the semiconductor device is determined to be within the temperature window.

A method can include, in response to a power supply voltage transition, setting a temperature window to a first temperature range by operation of a temperature circuit formed on a semiconductor device. In response to a temperature of the semiconductor device being determined to be outside of the first temperature range, changing the temperature range of the temperature window until the temperature of the semiconductor device is determined to be within the temperature window.

The present invention provides a fractional frequency divider, wherein the fractional frequency divider includes a plurality of registers, a counter, a control signal generator and a clock gating circuit. Regarding the plurality of registers, at least a portion of the registers are set to have values The counter is configured to sequentially generate a plurality of counter values, wherein the plurality of counter values correspond to the at least a portion of the registers, respectively, and the plurality of counter values are generated repeatedly The control signal generator is configured to generate a control signal based on the received counter value and the value of the corresponding register. The clock gating circuit is configured to refer to the control signal to mask or not mask an input clock signal to generate an output clock signal.

The present invention provides a fractional frequency divider, wherein the fractional frequency divider includes a plurality of registers, a counter, a control signal generator and a clock gating circuit. Regarding the plurality of registers, at least a portion of the registers are set to have values The counter is configured to sequentially generate a plurality of counter values, wherein the plurality of counter values correspond to the at least a portion of the registers, respectively, and the plurality of counter values are generated repeatedly The control signal generator is configured to generate a control signal based on the received counter value and the value of the corresponding register. The clock gating circuit is configured to refer to the control signal to mask or not mask an input clock signal to generate an output clock signal.

A microcontroller is coupled to a detection circuit which generates a detection signal. The microcontroller includes a processing circuit and an input-output circuit. The processing circuit generates an output signal according to the detection signal. In response to the output signal being at a specific level, the processing circuit enables a reset signal. The input-output circuit includes a latch circuit and a counter circuit. The latch circuit latches the output signal to generate a latched signal. The counter circuit starts adjusting the count value in response to the reset signal being enabled. The counter circuit changes the level of the latched signal in response to the count value being equal to a predetermined value.

A microcontroller is coupled to a detection circuit which generates a detection signal. The microcontroller includes a processing circuit and an input-output circuit. The processing circuit generates an output signal according to the detection signal. In response to the output signal being at a specific level, the processing circuit enables a reset signal. The input-output circuit includes a latch circuit and a counter circuit. The latch circuit latches the output signal to generate a latched signal. The counter circuit starts adjusting the count value in response to the reset signal being enabled. The counter circuit changes the level of the latched signal in response to the count value being equal to a predetermined value.

Design and methods for implementing a Rational Ratio Multiplier (RRM) with close to 50% duty cycle. This invention gives an optimal way to implement RRM that save both area and power for a given design and able to achieve a good accuracy of the output clock with a difference between the high period and the low period of the output clock by only half a cycle of the input clock which is the closest to get to 50% duty cycle clock.

Design and methods for implementing a Rational Ratio Multiplier (RRM) with close to 50% duty cycle. This invention gives an optimal way to implement RRM that save both area and power for a given design and able to achieve a good accuracy of the output clock with a difference between the high period and the low period of the output clock by only half a cycle of the input clock which is the closest to get to 50% duty cycle clock.