Abstract: A system and method for efficient management of resources within a semiconductor chip for an optimal combination of power reduction and high performance. An intergrated circuit, such as a system on a chip (SOC), includes at least two processing units. The second processing unit includes a cache. The SOC includes a power management unit (PMU) that determines whether a first activity level for the first processing unit is above a first threshold and a second activity level for the second processing unit is below a second threshold. If this condition is true, then the PMU places a limit on a highest power-performance state (P-state) used by the second processing unit. The PMU sends an indication to flush the at least one cache within the second processing unit. The PMU changes a P-state used by the first processing unit to a higher performance P-state.

Abstract: A method of regulating power states in a processing system may begin with a processor component reporting a present processor power state to an input-output hub, where the present processor power state corresponds to one of a plurality of different processor power states ranging from an active state to an inactive state. The input-output hub receives data indicative of the present processor power state and, in response to receiving the present processor power state, establishes a lowest allowable hub power state that corresponds to one of a plurality of different hub power states ranging from an active state to an inactive state. The method continues by determining a present hub power state for the input-output hub, wherein depth of the present hub power state is less than or equal to depth of the lowest allowable hub power state.

Abstract: A method and apparatus for dynamically controlling a cache size is disclosed. In one embodiment, a method includes changing an operating point of a processor from a first operating point to a second operating point, and selectively removing power from one or more ways of a cache memory responsive to changing the operating point. The method further includes processing one or more instructions in the processor subsequent to removing power from the one or more ways of the cache memory, wherein said processing includes accessing one or more ways of the cache memory from which power was not removed.

Abstract: Various computing devices and methods of managing the power consumption thereby are disclosed. In one aspect, a method of managing power consumption of a computing device that has a battery is provided. The method includes cycling the computing device between a connected standby active state and a connected standby idle state. The duration of the connected standby idle state is set based at least in part on a charge level of the battery.

Abstract: A method for power management is disclosed. The method may include monitoring requests for access to a memory of a memory subsystem by one or more processor cores; and monitoring requests for access to the memory conveyed by an input/output (I/O) unit. The method may further include determining if at least a first amount of time has elapsed since any one of the processor cores has asserted a memory access request and determining if at least a second amount of time has elapsed since the I/O unit has conveyed a memory access request. A first signal may be asserted if the first and second amounts of time have elapsed. A memory subsystem may be transitioned from operating in a full power state to a first low power state responsive to assertion of the first signal.

Abstract: A hierarchical memory request stream arbitration technique merges coherent memory request streams from multiple memory request sources and arbitrates the merged coherent memory request stream with requests from a non-coherent memory request stream. In at least one embodiment of the invention, a method of generating a merged memory request stream from a plurality of memory request streams includes merging coherent memory requests into a first serial memory request stream. The method includes selecting, by a memory controller circuit, a memory request for placement in the merged memory request stream from at least the first serial memory request stream and a merged non-coherent request stream. The merged non-coherent memory request stream is based on an indicator of a previous memory request selected for placement in the merged memory request stream.

Abstract: An apparatus and method for performance control of processing nodes is disclosed. In one embodiment, a system includes a processing node and a power management unit configured to, for each of a plurality of time intervals, monitor an activity level of the processing node, cause the processing node to operate at a high operating point during one successive time interval if the activity level in the given interval is greater than a high activity threshold, operate at a low operating point at least one successive time interval if the activity level is less than a low activity threshold, or enable operating system software to cause the processing node to operate at one of one or more predefined intermediate operating points of the plurality of operating points if the activity level is less than the high activity threshold and greater than the low activity threshold.

Abstract: A processor integrated circuit has one or more processor cores and a power management controller in a North-Bridge that generates a first power state recommendation for the one or more processor cores. The North-Bridge also receives a second power state recommendation from a South-Bridge integrated circuit. The North-Bridge determines a final power state for the one or more processor cores based on the first and second power state recommendations.

Abstract: A power controller can set the power state of a processor bridge based on which processor modules are in a communicative state. In addition, for a power state where selected processor modules are expected to be non-communicative, the power controller can set the supplied voltage to have a reduced voltage guard band as compared to other power states. These power management techniques can reduce the power consumed by the processor.

Abstract: An apparatus and method for dynamically adjusting power limits for processing nodes and other components, such as peripheral interfaces, is disclosed. The apparatus includes multiple processing nodes and other components, and further includes a power management unit configured to set a first frequency limit for at least one of the processing nodes responsive to receiving an indication of a first detected temperature greater than a first temperature threshold. Initial power limits are set below guard-band power limits for components that do not have reliable reporting of power consumption or for cost or power saving reasons. The amount of throttling of processing nodes is used to adjust the power limits for the processing nodes and these components.

Abstract: A processor includes a processor core and a power management controller operable to receive a timer event, store the timer event, generate a hardware system sleep command to enter a hardware system sleep state, and restore the timer event upon exiting from the hardware system sleep state.

Abstract: A system and method for efficient management of resources within a semiconductor chip for an optimal combination of power reduction and high performance. An intergrated circuit, such as a system on a chip (SOC), includes at least two processing units. The second processing unit includes a cache. The SOC includes a power management unit (PMU) that determines whether a first activity level for the first processing unit is above a first threshold and a second activity level for the second processing unit is below a second threshold. If this condition is true, then the PMU places a limit on a highest power-performance state (P-state) used by the second processing unit. The PMU sends an indication to flush the at least one cache within the second processing unit. The PMU changes a P-state used by the first processing unit to a higher performance P-state.

Abstract: A method and apparatus for dynamically controlling a cache size is disclosed. In one embodiment, a method includes changing an operating point of a processor from a first operating point to a second operating point, and selectively removing power from one or more ways of a cache memory responsive to changing the operating point. The method further includes processing one or more instructions in the processor subsequent to removing power from the one or more ways of the cache memory, wherein said processing includes accessing one or more ways of the cache memory from which power was not removed.

Abstract: Techniques are disclosed relating to managing power consumption and latencies for entry and exit of idle power states. In one embodiment, a processor includes a processing core configured to operate in a plurality of power states (e.g., C-states) that includes an operating power state and at least one idle power state. The processing core is also configured to operate in a plurality of performance states. The processor further includes a power management unit configured to receive a request from the processing core to enter the at least one idle power state. The power management unit is configured to select a first of the plurality of performance states (e.g., P-states) based on the requested idle power state. In one embodiment, the power management unit is further configured to cause the processing core to transition into the selected first performance state prior to entering the requested idle power state.

Abstract: A hierarchical memory request stream arbitration technique merges coherent memory request streams from multiple memory request sources and arbitrates the merged coherent memory request stream with requests from a non-coherent memory request stream. In at least one embodiment of the invention, a method of generating a merged memory request stream from a plurality of memory request streams includes merging coherent memory requests into a first serial memory request stream. The method includes selecting, by a memory controller circuit, a memory request for placement in the merged memory request stream from at least the first serial memory request stream and a merged non-coherent request stream. The merged non-coherent memory request stream is based on an indicator of a previous memory request selected for placement in the merged memory request stream.

Abstract: A method of regulating power states in a processing system may begin with a processor component reporting a present processor power state to an input-output hub, where the present processor power state corresponds to one of a plurality of different processor power states ranging from an active state to an inactive state. The input-output hub receives data indicative of the present processor power state and, in response to receiving the present processor power state, establishes a lowest allowable hub power state that corresponds to one of a plurality of different hub power states ranging from an active state to an inactive state. The method continues by determining a present hub power state for the input-output hub, wherein depth of the present hub power state is less than or equal to depth of the lowest allowable hub power state.

Abstract: A method for transitioning power states in a device includes designating a first reduced power state as a target power state. A first expected residency for the target power state is determined based on a counting of activity requests associated with the device. The device is transitioned to the target power state responsive to the expected residency satisfying a first predetermined threshold.

Abstract: A hierarchical memory request stream arbitration technique merges coherent memory request streams from multiple memory request sources and arbitrates the merged coherent memory request stream with requests from a non-coherent memory request stream. In at least one embodiment of the invention, a method of generating a merged memory request stream from a plurality of memory request streams includes merging coherent memory requests into a first serial memory request stream. The method includes selecting, by a memory controller circuit, a memory request for placement in the merged memory request stream from at least the first serial memory request stream and a merged non-coherent request stream. The merged non-coherent memory request stream is at least partially based on an indicator of a previous memory request selected for placement in the merged memory request stream.

Abstract: A system may comprise a plurality of processing units and a scheduler configured to maintain a record for each respective processing unit. Each respective record may comprise entries which may indicate 1) how long the respective processing unit has been residing in an idle state, 2) a present power-state in which the respective processing unit resides, and 3) whether the respective processing unit is a designated default (bootstrap) processing unit. The scheduler may select one or more of the plurality of processing units according to their respective records, and assign impending instructions to be executed on the selected one or more processing units. Where additional processing units are required, the scheduler may also insert an instruction to trigger an inter-processor interrupt to transition one or more processing units out of idle-state. The scheduler may then assign some impending instructions to these one or more processing units.

Abstract: A system may comprise a plurality of processing units, and a control unit and monitoring unit interfacing with the processing units. The control unit may receive requests for transitioning the processing units to respective target power-states, and specify respective target HW power-states corresponding to the respective target power-states. The monitoring unit may monitor operating characteristics of the system, and determine based on operating characteristics whether to allow the processing units to transition to the respective target hardware (HW) power-states. The control unit may be configured to change the respective target HW power-state to a respective updated HW power-state for each processing units for which it is determined that transition to its respective target HW power-state should not be allowed.