Abstract: In one embodiment, an integrated circuit includes a self calibration unit configured to iterate a test on a logic circuit in the integrated circuit at respectively lower supply voltage magnitudes until the test fails. A lowest supply voltage magnitude at which the test passes is used to generate a requested supply voltage magnitude for the integrated circuit. In an embodiment, an integrated circuit includes a series connection of logic gates physically distributed over an area of the integrated circuit, and a measurement unit configured to launch a logical transition into the series and detect a corresponding transition at the output of the series. The amount of time between the launch and the detection is used to request a supply voltage magnitude for the integrated circuit.

Abstract: A memory circuit is disclosed that comprises a plurality of memory cells coupled to a virtual voltage rail. The plurality of memory cells may form, for example, a sub-array of an SRAM array. A switching circuit may be coupled between the virtual voltage rail and a voltage supply node, and a comparator may be coupled to compare a voltage level present on the virtual voltage rail to a reference voltage to thereby provide an output signal based on the comparison. The switching circuit may be configured to electrically couple the virtual voltage rail to the voltage supply node depending upon the output signal. In some embodiments, the switching circuit may be implemented using either a PMOS transistor or an NMOS transistor, although other embodiments may employ other switching circuits.

Abstract: In one embodiment, an integrated circuit comprises at least one logic circuit supplied by a first supply voltage and at least one memory circuit coupled to the logic circuit and supplied by a second supply voltage. The memory circuit is configured to be read and written responsive to the logic circuit even if the first supply voltage is less than the second supply voltage during use. In another embodiment, a method comprises a logic circuit reading a memory cell, the logic circuit supplied by a first supply voltage; and the memory cell responding to the read using signals that are referenced to the first supply voltage, wherein the memory cell is supplied with a second supply voltage that is greater than the first supply voltage during use.

Abstract: In one embodiment, an apparatus comprises a circuit supplied by a first supply voltage during use, the circuit having at least a first input signal; and a level shifter supplied by the first supply voltage during use and coupled to provide the first input signal to the circuit. The level shifter is coupled to receive a second input signal sourced from circuitry supplied by a second supply voltage during use, and is configured to generate the first input signal by level shifting the second input signal. Coupled to receive a power control signal indicating, when asserted, that the second supply voltage is to be powered down, the level shifter is configured to assert a predetermined level on the first input signal independent of the second input signal and responsive to an assertion of the power control signal.

Abstract: In one embodiment, an integrated circuit comprises at least one measurement unit configured to generate an output indicative of a supply voltage at which the integrated circuit is operable for a given operating frequency and a control unit coupled to receive the output. The control unit is configured to generate a voltage control output indicative of a requested supply voltage for the integrated circuit responsive to the output. The voltage control output may be output from the integrated circuit for use by circuitry external to the integrated circuit in generating the supply voltage for the integrated circuit.

Abstract: In one embodiment, an apparatus comprises a circuit supplied by a first supply voltage during use, the circuit having at least a first input signal; and a level shifter supplied by the first supply voltage during use and coupled to provide the first input signal to the circuit. The level shifter is coupled to receive a second input signal sourced from circuitry supplied by a second supply voltage during use, and is configured to generate the first input signal by level shifting the second input signal. Coupled to receive a power control signal indicating, when asserted, that the second supply voltage is to be powered down, the level shifter is configured to assert a predetermined level on the first input signal independent of the second input signal and responsive to an assertion of the power control signal.

Abstract: In one embodiment, an integrated circuit comprises at least one measurement unit configured to generate an output indicative of a supply voltage at which the integrated circuit is operable for a given operating frequency and a control unit coupled to receive the output. The control unit is configured to generate a voltage control output indicative of a requested supply voltage for the integrated circuit responsive to the output. The voltage control output may be output from the integrated circuit for use by circuitry external to the integrated circuit in generating the supply voltage for the integrated circuit.

Abstract: In one embodiment, an apparatus is provided for a system including an integrated circuit coupled to a node to receive a supply voltage and having bypass capacitors coupled in parallel with the integrated circuit to the node. The apparatus comprises a first capacitor, a switch coupled to the first capacitor, and a voltage source configured to charge the first capacitor. The switch is coupled to receive a control signal that is asserted, during use, if the supply voltage to an integrated circuit is to be increased. The switch is configured to electrically couple the first capacitor to the node in response to an assertion of the control signal. When electrically coupled to the node, the first capacitor supplies charge to the bypass capacitors. A system comprising the apparatus, the node, the integrated circuit, and the bypass capacitors is also contemplated in some embodiments.

Abstract: In one embodiment, an apparatus is provided for a system including an integrated circuit coupled to a node to receive a supply voltage and having bypass capacitors coupled in parallel with the integrated circuit to the node. The apparatus comprises a first capacitor, a switch coupled to the first capacitor, and a voltage source configured to charge the first capacitor. The switch is coupled to receive a control signal that is asserted, during use, if the supply voltage to an integrated circuit is to be increased. The switch is configured to electrically couple the first capacitor to the node in response to an assertion of the control signal. When electrically coupled to the node, the first capacitor supplies charge to the bypass capacitors. A system comprising the apparatus, the node, the integrated circuit, and the bypass capacitors is also contemplated in some embodiments.

Abstract: In one embodiment, a level shifter circuit may include a shift stage that also embeds transistors that implement a logic operation on two or more inputs to the level shifter. At least one of the inputs may be sourced from circuitry that is powered by a different power supply than the level shifter and circuitry that receives the level shifter output. Additionally, the level shifter includes one or more dummy transistors that match transistors the perform the logic operation, to improve symmetry of the level shifter circuit. In some embodiments, certain design and layout rules may be applied to the level shifter circuit to limit variation in the symmetry over various manufacturing variations.

Abstract: In one embodiment, an integrated circuit comprises at least one logic circuit supplied by a first supply voltage and at least one memory circuit coupled to the logic circuit and supplied by a second supply voltage. The memory circuit is configured to be read and written responsive to the logic circuit even if the first supply voltage is less than the second supply voltage during use. In another embodiment, a method comprises a logic circuit reading a memory cell, the logic circuit supplied by a first supply voltage; and the memory cell responding to the read using signals that are referenced to the first supply voltage, wherein the memory cell is supplied with a second supply voltage that is greater than the first supply voltage during use.

Abstract: In one embodiment, an integrated circuit comprises at least one logic circuit supplied by a first supply voltage and at least one memory circuit coupled to the logic circuit and supplied by a second supply voltage. The memory circuit is configured to be read and written responsive to the logic circuit even if the first supply voltage is less than the second supply voltage during use. In another embodiment, a method comprises a logic circuit reading a memory cell, the logic circuit supplied by a first supply voltage; and the memory cell responding to the read using signals that are referenced to the first supply voltage, wherein the memory cell is supplied with a second supply voltage that is greater than the first supply voltage during use.

Abstract: In one embodiment, an apparatus to synchronously communicate on an interface that has an associated interface clock for a circuit that has an internal clock used internal to the circuit comprises a control circuit coupled to receive the internal clock and the interface clock. The control circuit is configured to sample the interface clock multiple times per clock cycle of the internal clock and to detect a phase difference, to a granularity of the samples, between the internal clock and the interface clock. The apparatus comprises a data path that is configured to transport data between an internal clock domain and an interface clock domain. The data path is configured to provide at least two different timings on the transported data relative to the internal clock. The control circuit is coupled to the data path and is configured to select one of the timings responsive to a detected phase difference.

Abstract: In one embodiment, an apparatus comprises a circuit supplied by a first supply voltage during use, the circuit having at least a first input signal; and a level shifter supplied by the first supply voltage during use and coupled to provide the first input signal to the circuit. The level shifter is coupled to receive a second input signal sourced from circuitry supplied by a second supply voltage during use, and is configured to generate the first input signal by level shifting the second input signal. Coupled to receive a power control signal indicating, when asserted, that the second supply voltage is to be powered down, the level shifter is configured to assert a predetermined level on the first input signal independent of the second input signal and responsive to an assertion of the power control signal.

Abstract: In one embodiment, an integrated circuit comprises at least one logic circuit supplied by a first supply voltage and at least one memory circuit coupled to the logic circuit and supplied by a second supply voltage. The memory circuit is configured to be read and written responsive to the logic circuit even if the first supply voltage is less than the second supply voltage during use. In another embodiment, a method comprises a logic circuit reading a memory cell, the logic circuit supplied by a first supply voltage; and the memory cell responding to the read using signals that are referenced to the first supply voltage, wherein the memory cell is supplied with a second supply voltage that is greater than the first supply voltage during use.

Abstract: In one embodiment, an integrated circuit comprises resonance limiter circuits coupled to a power supply connection of the integrated circuit. The resonance limiter circuits are configured to detect oscillation on the power supply connection at a resonant frequency, and to dampen the resonant frequency oscillation responsive to detecting the oscillation. In some embodiments, the resonance limiter circuits may damp oscillation at or above the resonant frequency or approximately the resonant frequency (e.g. somewhat below the resonance frequency). The resonant frequency depends on a package of the integrated circuit. In an embodiment, a resonance limiter circuit comprises a filter and a transistor coupled in parallel with the filter between a power supply connection and a ground connection. The filter is tuned to approximately a resonant frequency (e.g. the lowest resonant frequency) that depends on a package corresponding to an integrated circuit into which the resonance limiter circuit is fabricated.

Abstract: In one embodiment, an integrated circuit comprises at least one logic circuit supplied by a first supply voltage and at least one memory circuit coupled to the logic circuit and supplied by a second supply voltage. The memory circuit is configured to be read and written responsive to the logic circuit even if the first supply voltage is less than the second supply voltage during use. In another embodiment, a method comprises a logic circuit reading a memory cell, the logic circuit supplied by a first supply voltage; and the memory cell responding to the read using signals that are referenced to the first supply voltage, wherein the memory cell is supplied with a second supply voltage that is greater than the first supply voltage during use.

Abstract: In one embodiment, an integrated circuit comprises resonance limiter circuits coupled to a power supply connection of the integrated circuit. The resonance limiter circuits are configured to detect oscillation on the power supply connection at a resonant frequency, and to dampen the resonant frequency oscillation responsive to detecting the oscillation. In some embodiments, the resonance limiter circuits may damp oscillation at or above the resonant frequency or approximately the resonant frequency (e.g. somewhat below the resonance frequency). The resonant frequency depends on a package of the integrated circuit. In an embodiment, a resonance limiter circuit comprises a filter and a transistor coupled in parallel with the filter between a power supply connection and a ground connection. The filter is tuned to approximately a resonant frequency (e.g. the lowest resonant frequency) that depends on a package corresponding to an integrated circuit into which the resonance limiter circuit is fabricated.

Abstract: In one embodiment, an integrated circuit comprises at least one measurement unit configured to generate an output indicative of a supply voltage at which the integrated circuit is operable for a given operating frequency and a control unit coupled to receive the output. The control unit is configured to generate a voltage control output indicative of a requested supply voltage for the integrated circuit responsive to the output. The voltage control output may be output from the integrated circuit for use by circuitry external to the integrated circuit in generating the supply voltage for the integrated circuit.

Abstract: In one embodiment, an apparatus comprises a voltage-controlled oscillator (VCO) that comprises a circuit coupled to receive an input control voltage to the VCO and configured to generate a second voltage responsive to the input control voltage, a summator coupled to receive the input control voltage and the second voltage, and an oscillator coupled to receive the output voltage of the summator. The summator is configured to combine the input control voltage and the second voltage to generate the output voltage. The oscillator is configured to oscillate an output signal, wherein a frequency of oscillation of the output signal is controlled by the output voltage of the summator.