Abstract: Various embodiments of a method and apparatus for performing adaptive voltage adjustment based on temperature value are disclosed. In one embodiment, and integrated circuit (IC) includes logic circuitry having at least one temperature sensor therein. The IC also includes a power management circuit coupled to receive temperature readings from the temperature sensor. The power management circuit is configured to determine a temperature of the IC based on a temperature reading received from the temperature sensor. The power management circuit may compare the determined temperature to a temperature threshold. If the temperature exceeds a temperature threshold value, the power management circuit may cause the operating voltage to be reduced by an amount equivalent to a voltage guard band.

Abstract: In an embodiment, a power management unit (PMU) may automatically transition (in hardware) the performance states of one or more performance domains in a system. The target performance states to which the performance domains are to transition may be programmable in the PMU by software, and software may signal the PMU that a processor in the system is to enter the sleep state. The PMU may control the transition of the performance domains to the target performance states, and may cause the processor to enter the sleep state. In an embodiment, the PMU may be programmable with a second set of target performance states to which the performance domains are to transition when the processor exits the sleep state. The PMU may control the transition of the performance domains to the second targeted performance states and cause the processor to exit the sleep state.

Abstract: Various embodiments of a method and apparatus for performing adaptive voltage adjustment based on temperature value are disclosed. In one embodiment, and integrated circuit (IC) includes logic circuitry having at least one temperature sensor therein. The IC also includes a power management circuit coupled to receive temperature readings from the temperature sensor. The power management circuit is configured to determine a temperature of the IC based on a temperature reading received from the temperature sensor. The power management circuit may compare the determined temperature to a temperature threshold. If the temperature exceeds a temperature threshold value, the power management circuit may cause the operating voltage to be reduced by an amount equivalent to a voltage guard band.

Abstract: In an embodiment, a power management unit (PMU) may automatically transition (in hardware) the performance states of one or more performance domains in a system. The target performance states to which the performance domains are to transition may be programmable in the PMU by software, and software may signal the PMU that a processor in the system is to enter the sleep state. The PMU may control the transition of the performance domains to the target performance states, and may cause the processor to enter the sleep state. In an embodiment, the PMU may be programmable with a second set of target performance states to which the performance domains are to transition when the processor exits the sleep state. The PMU may control the transition of the performance domains to the second targeted performance states and cause the processor to exit the sleep state.

Abstract: A method an apparatus for a power switch acceleration scheme during wakeup is disclosed. In one embodiment, an integrated circuit includes at least one power gated circuit block. The power gated circuit block includes a virtual voltage node from which a voltage is provided to the circuitry of the block when active. Power switches are coupled between the virtual voltage node and a corresponding global voltage node. When the power gated circuit block is powered on, power switches are activated sequentially. The rate at which power switches are activated is increased as the voltage on the virtual voltage node increases. Sequentially activating the power switches may prevent an excess of current inrush into the power gated circuit block. The increase in the rate at which power switches are activated when the voltage on the virtual voltage node is at least at a certain level may allow for a faster wakeup.

Abstract: A method an apparatus for a power switch acceleration scheme during wakeup is disclosed. In one embodiment, an integrated circuit includes at least one power gated circuit block. The power gated circuit block includes a virtual voltage node from which a voltage is provided to the circuitry of the block when active. Power switches are coupled between the virtual voltage node and a corresponding global voltage node. When the power gated circuit block is powered on, power switches are activated sequentially. The rate at which power switches are activated is increased as the voltage on the virtual voltage node increases. Sequentially activating the power switches may prevent an excess of current inrush into the power gated circuit block. The increase in the rate at which power switches are activated when the voltage on the virtual voltage node is at least at a certain level may allow for a faster wakeup.

Abstract: In an embodiment, a power management unit (PMU) may automatically transition (in hardware) the performance states of one or more performance domains in a system. The target performance states to which the performance domains are to transition may be programmable in the PMU by software, and software may signal the PMU that a processor in the system is to enter the sleep state. The PMU may control the transition of the performance domains to the target performance states, and may cause the processor to enter the sleep state. In an embodiment, the PMU may be programmable with a second set of target performance states to which the performance domains are to transition when the processor exits the sleep state. The PMU may control the transition of the performance domains to the second targeted performance states and cause the processor to exit the sleep state.

Abstract: A multi-path power switch scheme for functional block wakeup is disclosed. The scheme may be applied to functional blocks of an integrated circuit. When a power on procedure is initiated within a given functional block, a first group of power switches in a functional block may be powered on, while a second group of power switches is inhibited from powering on. After a predetermined time has elapsed, activation of the second group of power switches is initiated. After initiation of a power up procedure for a given functional block, the powering up of a second functional block to be powered on may initially be inhibited. After a predetermined time has elapsed, the powering on of the second functional block may be initiated. Overlap between times when the first and second groups of switches are active may depend on process, voltage, and temperature variations.

Abstract: A method an apparatus for a power switch acceleration scheme during wakeup is disclosed. In one embodiment, an integrated circuit includes at least one power gated circuit block. The power gated circuit block includes a virtual voltage node from which a voltage is provided to the circuitry of the block when active. Power switches are coupled between the virtual voltage node and a corresponding global voltage node. When the power gated circuit block is powered on, power switches are activated sequentially. The rate at which power switches are activated is increased as the voltage on the virtual voltage node increases. Sequentially activating the power switches may prevent an excess of current inrush into the power gated circuit block. The increase in the rate at which power switches are activated when the voltage on the virtual voltage node is at least at a certain level may allow for a faster wakeup.

Abstract: In an embodiment, an integrated circuit includes a power gated block and a power manager circuit. The power manager circuit is configured to provide a block enable signal and at least one select signal to the power gated block. The power manager may generate the select signal responsive to various parameters that affect the speed of the integrated circuit, such as power supply voltage magnitude, operating temperature, and/or process corner. The power gated block may control the rate at which power switches are enabled based on the select signal or signals. For example, the power switches may be enabled in a more parallel or more serial fashion and/or the drive strength of block enable buffering to the power switches may be varied. In another embodiment, the power manager circuit may assert multiple block enables to the power gated block (which are connected to separate sets of power switches), and may control the timing of assertion of the enables to control the rate at which power switches are enabled.

Abstract: A method and apparatus for temperature sensor calibration is disclosed. In one embodiment, an integrated circuit (IC) is tested at a first known temperature corresponding to a first temperature threshold. During the test, a first temperature reading is obtained from a temperature sensor. A first offset is calculated by determining the difference between the first known temperature and the first temperature reading. The first offset is recorded in a storage unit for later use during operation of the IC. During operation, the first offset may be added to temperature readings obtained from a temperature sensing unit to produce an adjusted temperature value. The adjusted temperature value may be compared to one or more temperature thresholds. Based on the comparisons, a power management unit may perform power control actions.

Abstract: A system and method for efficiently managing multiple PLLs on a system on a chip (SOC). A SOC includes a hardware phase lock loop (PLL) switching control block coupled to a software interface. The hardware PLL switching (HPS) control block receives PLL switch requests from software. The request identifies a given core clock received by a given processing core of multiple processor cores on the SOC and indicates the identified core clock is not to be provided anymore by a current PLL. The request indicates a given search method including search conditions. The HPS control block searches for a target PLL that satisfies these search conditions. In response to finding the target PLL, the HPS control block changes clock network connections and parameters across the die of the SOC. These changes across the die disconnect the identified core clock from the current PLL and connects the identified core clock to the target PLL.

Abstract: In an embodiment, an integrated circuit may include one or more power managed blocks and a power manager circuit. The power manager circuit may be configured to generate a block enable for each power managed block and a block enable clock. The power managed block may generate local block enables to various power switches in the power managed block, staggering the block enables over two or more block enable clock cycles. In particular, the power managed block may include a set of series-connected flops that receive the block enable from the power manager circuit. The output of each flop may be coupled to a respective set of power switches and may enabled those switches. The change in current flow due to enabling and/or disabling the power managed block may thus be controlled. In an embodiment, the frequency of the block enable clock may be set to a defined value independent of process, voltage, and temperature conditions in the integrated circuit.

Abstract: In an embodiment, an integrated circuit comprises a plurality of temperature sensors and a power manager coupled thereto. The temperature sensors are physically distributed over an area of the integrated circuit that is occupied by logic circuitry implementing the operations for which the integrated circuit is designed. The power manager is configured to transmit a power supply voltage request to an external power supply module, the power supply voltage request indicating a requested magnitude of the power supply voltage for the integrated circuit. The power manager is configured to modify the requested magnitude responsive to indications from each of the plurality of temperatures sensors that represent a temperature of the integrated circuit sensed by each of the plurality of temperature sensors.

Abstract: In one embodiment, a power gated circuit block includes power switches that couple at least one of the power supply grids within the block to the global power supply grids of the integrated circuit. The power switches receive an enable that indicates whether or not the power gated block is enabled or disabled. If the power gated block is enabled, the power switches are turned on and electrically connect the global power supply grid with the internal (or local) power supply grid; otherwise the power switches electrically isolate the local power supply grid from the global power supply grid. The power switches are physically distributed over an area occupied by the power gated block, including near an edge of the area. The number of power switches near the edge is greater than the number of switches included at other locations in the area to provide a worst case impedance experienced at points throughout the area that is approximately equal.

Abstract: CMOS circuitry having mixed threshold voltages is disclosed. Circuits may be implemented using PMOS transistors, NMOS transistors, or both. For at least one given type of transistor (PMOS or NMOS), a circuit includes at least one transistor configured to switch at a first nominal threshold voltage and at least one transistor configured to switch at a second nominal threshold voltage. The different threshold voltages among a given transistor type are realized by varying the thickness of the transistor gate oxides and/or the channel dopant density, for example.

Abstract: An apparatus and method for detecting noise in a power supply voltage. A circuit may include a voltage generation unit coupled to receive a power supply voltage, and a detection unit. The voltage generation unit may generate first and second voltages using the power supply voltage, and may vary the relationship therebetween responsive to fluctuations in the power supply voltage. A detection unit may detect the variations in the relationship between the first and second voltages that result from fluctuations in the power supply voltage. Responsive to detecting the variations, the detection unit may generate pulses to be provided to a counter. The counter may update a count value responsive to receiving pulses.

Abstract: In an embodiment, an integrated circuit may include one or more power managed blocks and a power manager circuit. The power manager circuit may be configured to generate a block enable for each power managed block and a block enable clock. The power managed block may generate local block enables to various power switches in the power managed block, staggering the block enables over two or more block enable clock cycles. In particular, the power managed block may include a set of series-connected flops that receive the block enable from the power manager circuit. The output of each flop may be coupled to a respective set of power switches and may enabled those switches. The change in current flow due to enabling and/or disabling the power managed block may thus be controlled. In an embodiment, the frequency of the block enable clock may be set to a defined value independent of process, voltage, and temperature conditions in the integrated circuit.

Abstract: In an embodiment, an integrated circuit includes a power gated block and a power manager circuit. The power manager circuit is configured to provide a block enable signal and at least one select signal to the power gated block. The power manager may generate the select signal responsive to various parameters that affect the speed of the integrated circuit, such as power supply voltage magnitude, operating temperature, and/or process corner. The power gated block may control the rate at which power switches are enabled based on the select signal or signals. For example, the power switches may be enabled in a more parallel or more serial fashion and/or the drive strength of block enable buffering to the power switches may be varied. In another embodiment, the power manager circuit may assert multiple block enables to the power gated block (which are connected to separate sets of power switches), and may control the timing of assertion of the enables to control the rate at which power switches are enabled.

Abstract: An apparatus and method for detecting noise in a power supply voltage. A circuit may include a voltage generation unit coupled to receive a power supply voltage, and a detection unit. The voltage generation unit may generate first and second voltages using the power supply voltage, and may vary the relationship therebetween responsive to fluctuations in the power supply voltage. A detection unit may detect the variations in the relationship between the first and second voltages that result from fluctuations in the power supply voltage. Responsive to detecting the variations, the detection unit may generate pulses to be provided to a counter. The counter may update a count value responsive to receiving pulses.