Abstract: A method and apparatus for calibrating a temperature sensor is disclosed. In one embodiment, a method comprises generating first and second digital values based respectively on first and second voltages applied to a portion of a temperature sensor circuit. An arithmetic circuit may derive the value of the second voltage based on the first and second digital values. The method further comprises determining an initial value of a constant based on values of the first and second voltages, and determining a final value of the constant based on the initial voltage and at least one voltage offset. The constant may then be used in determining temperature readings for the temperature sensor.

Abstract: An embodiment includes a circuit block configured to distribute a power signal to a plurality of voltage sense signals, and a voltage regulator configured to generate a regulated voltage level on the power signal. The embodiment also includes a sensing circuit configured to perform a sequence of comparisons of respective voltage levels of the plurality of voltage sense signals using a selection criterion. To perform the sequence of comparisons, the sensing circuit may be configured to select either a first voltage sense signal or a second voltage sense signal to generate a first output voltage sense signal. The sensing circuit may also be configured to select either a third voltage sense signal or a previously generated output voltage sense signal to generate a feedback signal. The voltage regulator circuit may be further configured to modify the regulated voltage level using the feedback signal.

Abstract: A method and apparatus for calibrating a temperature sensor is disclosed. In one embodiment, a method comprises generating first and second digital values based respectively on first and second voltages applied to a portion of a temperature sensor circuit. An arithmetic circuit may derive the value of the second voltage based on the first and second digital values. The method further comprises determining an initial value of a constant based on values of the first and second voltages, and determining a final value of the constant based on the initial voltage and at least one voltage offset. The constant may then be used in determining temperature readings for the temperature sensor.

Abstract: A system that generates a click signal includes a first digitally controlled oscillator (DCO) having a first fundamental frequency, and a second DCO having a second fundamental frequency. The system also includes a Muller C-element, which combines outputs of the first and second DCOs to produce the clock signal, which feeds back into the first and second DCOs. During a calibration operation, while the second DCO is set to a frequency larger than the target frequency, the system adjusts the first DCO with reference to a first feedback loop, which includes the first DCO, so that the clock signal matches the target frequency, and while the first DCO is set to the adjusted first fundamental frequency plus a frequency offset, the system adjusts the second DCO with reference to a second feedback loop, which includes the second DCO, so that the clock signal matches the target frequency.

Abstract: Embodiments of a temperature sensing apparatus are disclosed. The apparatus may include a voltage generator and circuitry. The voltage generator may generate a first voltage level and a second voltage level dependent on an operating temperature. In response to a given change in the operating temperature, the first and second voltage levels may change, with the second voltage level changing by a different amount than the first voltage level. The voltage generator may generate a third voltage level. The circuitry may measure the first voltage level, the second voltage level, and the third voltage level, and may calculate the operating temperature dependent on a ratio of a difference between the first voltage level and the second voltage level and the third voltage level.

Abstract: Implementations of the present disclosure involve a system and/or method for measuring on-die voltage levels of an integrated circuit through a digital sampling circuit. In particular, the system and/or method utilize a delay line based analog-to-digital sampling circuit that produces a voltage reading over time, such as at every high frequency clock cycle. In one embodiment, the digital sampling circuit or digital voltage monitor circuit includes a coarse delay component or circuit that further delays the propagation of a clock signal through the delay line. The coarse delay circuit may be programmed to delay the propagation of the signal through the delay line in such a manner as to allow for multiple edges of a clock or test signal to travel simultaneously down the delay line and increase the sensitivity of the circuit.

Abstract: Implementations of the present disclosure involve a system and/or method for measuring on-die voltage levels of an integrated circuit through a digital sampling circuit. In particular, the system and/or method utilize a delay line based analog-to-digital sampling circuit that produces a voltage reading over time, such as at every high frequency clock cycle. In one embodiment, the digital sampling circuit may include a clock jitter monitor circuit configured with a constant supply voltage. This clock jitter monitor is configured to measure the clock jitter that is experienced by the digital voltage monitor circuit and, when compared to measured voltage captured by the circuit, may be used to calibrate or otherwise correct the readings provided by the digital voltage monitor circuit.

Abstract: In an integrated circuit that provides a clock signal, an asymmetric frequency-locked loop (AFLL) includes a first digitally controlled oscillator (DCO) that outputs a first signal having a first fundamental frequency, and a second DCO that outputs a second signal having a second fundamental frequency. The integrated circuit includes a voltage regulator that provides a power-supply voltage to the second DCO. Moreover, the AFLL includes control logic that selects one of the first DCO and the second DCO based on an instantaneous value of a power-supply voltage and an average power-supply voltage. Furthermore, the AFLL adjusts a gain of the selected DCO in the first sub-frequency-locked loop based on the instantaneous value of the power-supply voltage and the average power-supply voltage. In this way, an impact of power-supply voltage variations on a time-critical path in the integrated circuit is reduced.

Abstract: Embodiments of a temperature sensing apparatus are disclosed. The apparatus may include a voltage generator and circuitry. The voltage generator may generate a first voltage level and a second voltage level dependent on an operating temperature. In response to a given change in the operating temperature, the first and second voltage levels may change, with the second voltage level changing by a different amount than the first voltage level. The voltage generator may generate a third voltage level. The circuitry may measure the first voltage level, the second voltage level, and the third voltage level, and may calculate the operating temperature dependent on a ratio of a difference between the first voltage level and the second voltage level and the third voltage level.

Abstract: Implementations of the present disclosure involve a system and/or method for measuring on-die voltage levels of an integrated circuit through a digital sampling circuit. In particular, the system and/or method utilize a delay line based analog-to-digital sampling circuit that produces a voltage reading over time, such as at every high frequency clock cycle. In one embodiment, the digital sampling circuit or digital voltage monitor circuit includes a coarse delay component or circuit that further delays the propagation of a clock signal through the delay line. The coarse delay circuit may be programmed to delay the propagation of the signal through the delay line in such a manner as to allow for multiple edges of a clock or test signal to travel simultaneously down the delay line and increase the sensitivity of the circuit.

Abstract: Implementations of the present disclosure involve a system and/or method for measuring on-die voltage levels of an integrated circuit through a digital sampling circuit. In particular, the system and/or method utilize a delay line based analog-to-digital sampling circuit that produces a voltage reading over time, such as at every high frequency clock cycle. In one embodiment, the digital sampling circuit may include a clock jitter monitor circuit configured with a constant supply voltage. This clock jitter monitor is configured to measure the clock jitter that is experienced by the digital voltage monitor circuit and, when compared to measured voltage captured by the circuit, may be used to calibrate or otherwise correct the readings provided by the digital voltage monitor circuit.

Abstract: In an integrated circuit that provides a clock signal, an asymmetric frequency-locked loop (AFLL) includes a first digitally controlled oscillator (DCO) that outputs a first signal having a first fundamental frequency, and a second DCO that outputs a second signal having a second fundamental frequency. The integrated circuit includes a voltage regulator that provides a power-supply voltage to the second DCO. Moreover, the AFLL includes control logic that selects one of the first DCO and the second DCO based on an instantaneous value of a power-supply voltage and an average power-supply voltage. Furthermore, the AFLL adjusts a gain of the selected DCO in the first sub-frequency-locked loop based on the instantaneous value of the power-supply voltage and the average power-supply voltage. In this way, an impact of power-supply voltage variations on a time-critical path in the integrated circuit is reduced.

Abstract: A level shifter and integrated level shifter and metastability resolution flop circuit are disclosed. A circuit includes a generation circuit, in a first voltage domain, coupled to receive a logic signal via a single-ended input and configured to generate true and complementary values of the logic signal. The circuit further includes a storage circuit coupled to receive the true and complementary values of the logic signal from the generation circuit. The storage circuit is configured to store the true and complementary values of the logic signal. The storage circuit is in a second voltage domain. The circuit further includes an output circuit coupled to the storage circuit and configured to provide a differential output signal having true and complementary values corresponding to the true and complementary values of the logic signal. The circuit may be combined with a latch circuit coupled to receive the differential output signal.

Abstract: A system and method of shifting a data signal from a first voltage domain having a first logic level to a second voltage domain having a second logic level, the second logic level having a second logical high state greater than a first logical high state in the first logic level and a single power supply logic level shifter circuit having a single power supply source, an input node and an output node, the input node coupled to a sender circuit in the first voltage domain and the output node coupled to a receiver circuit in the second voltage domain, the single power supply source being coupled only to a single power grid in the second voltage domain.

Abstract: A level shifter and integrated level shifter and metastability resolution flop circuit are disclosed. A circuit includes a generation circuit, in a first voltage domain, coupled to receive a logic signal via a single-ended input and configured to generate true and complementary values of the logic signal. The circuit further includes a storage circuit coupled to receive the true and complementary values of the logic signal from the generation circuit. The storage circuit is configured to store the true and complementary values of the logic signal. The storage circuit is in a second voltage domain. The circuit further includes an output circuit coupled to the storage circuit and configured to provide a differential output signal having true and complementary values corresponding to the true and complementary values of the logic signal. The circuit may be combined with a latch circuit coupled to receive the differential output signal.

Abstract: Embodiments include systems and methods for asynchronous, glitch-free clock switching across a wide range of clock frequencies with minimal clock down time. Embodiments effectively provide two stages of synchronization across two independent clock domains. In a first synchronization stage, a received, asynchronous clock select signal is translated into a synchronized clock select signal that is effectively synchronous with respect to a first clock domain and is still effectively asynchronous with respect to a second clock domain. In a second synchronization stage, the synchronized clock select signal is resynchronized so as to be effectively synchronous with respect to the second clock domain. The synchronized select signal can be used to disable the clock of the first clock domain, and the resynchronized clock select signal can be used to enable the clock of the second clock domain.

Abstract: Embodiments include systems and methods for asynchronous, glitch-free clock switching across a wide range of clock frequencies with minimal clock down time. Embodiments effectively provide two stages of synchronization across two independent clock domains. In a first synchronization stage, a received, asynchronous clock select signal is translated into a synchronized clock select signal that is effectively synchronous with respect to a first clock domain and is still effectively asynchronous with respect to a second clock domain. In a second synchronization stage, the synchronized clock select signal is resynchronized so as to be effectively synchronous with respect to the second clock domain. The synchronized select signal can be used to disable the clock of the first clock domain, and the resynchronized clock select signal can be used to enable the clock of the second clock domain.

Abstract: In an integrated circuit that provides a clock signal, an asymmetric frequency-locked loop (AFLL) includes a first digitally controlled oscillator (DCO) that outputs a first signal having a first fundamental frequency, and a second DCO that outputs a second signal having a second fundamental frequency that is less than the first fundamental frequency. Moreover, the AFLL includes control logic that selects one of the first DCO and the second DCO based on an instantaneous value of a power-supply voltage and an average power-supply voltage so that an impact of power-supply voltage variations on a time-critical path in the integrated circuit is reduced. For example, the control logic may select the first DCO if the instantaneous value of the power-supply voltage is greater than the average power-supply voltage; otherwise, the control logic may select the second DCO.

Abstract: A system and method of shifting a data signal from a first voltage domain having a first logic level to a second voltage domain having a second logic level, the second logic level having a second logical high state greater than a first logical high state in the first logic level and a single power supply logic level shifter circuit having a single power supply source, an input node and an output node, the input node coupled to a sender circuit in the first voltage domain and the output node coupled to a receiver circuit in the second voltage domain, the single power supply source being coupled only to a single power grid in the second voltage domain.

Abstract: The variable frequency oscillator is capable of operation at a low power supply voltage and oscillating at a high frequency. A phase locked loop and a clock synchronizer use the variable frequency oscillator and have a wide oscillation frequency range. The variable frequency oscillator has plural delay cells which are cascaded and the output of the final stage delay cell is fed back to the input of the first stage delay cell. Each of the delay cells includes a differential amplifier and a positive feedback circuit, connected with input and output terminals intersecting with each other. The feedback circuit has complementary amplifiers each having an input terminal formed by connecting together gates of a pMOS and an nMOS transistor and an output terminal formed by connecting together the drains thereof.