Qualcomm Incorporated

International Business Machines Corporation

Jeffrey Todd Bridges

Thomas Andrew Sartorius

James Norris Dieffenderfer

Rodney Wayne Smith

Victor Roberts Augsburg

Michael Scott McIlvaine

Brian Stempel

Shivam Priyadarshi

Gerald Paul Michalak

Sanjay Bhikhubhai Patel

Raguram Damodaran

Ryan Donovan Wells

Yeshwant Nagaraj Kolla

Kenneth Alan Dockser

Thomas Kevin Collopy

Robert Douglas Clancy

Richard Alan Moore

Richard Gerard Hofmann

Thomas Philip Speier

Norman S Gargash

Chiaming Chai

Jeffrey Herbert Fischer

Mark Michael Schaffer

Anil Krishna

Gabriel Martel Tarr

Gordon Taylor Davis

Michael Steven Siegel

Carl Alan Waldspurger

Harold Wade Cain, Iii

Francois Ibrahim Atallah

Burt Lee Price

Juan Guillermo Revilla

Keith Alan Bowman

Rami Mohammad Al Sheikh

Manish Garg

Liang Dai

Michael ThaiThanh Phan

Jihoon Jeong

Steven Mark Millendorf

Derek Robert Hower

Gregory Christopher Burda

Harry I Linzer

Dennis Charles Wilkerson

Robert L Goldiez

Shraddha Sridhar

Edward Hammond Green, Iii

William Robert Flederbach

Brandon Wayne Lewis

Brian Joseph Kopec

David Otero

Les Mark DeBruyne

Weihua Chen

SeyedMajid Zahedi

Chih Kang Lin

Thomas Joseph Irene

Michael S Mcilvaine

Sarthak Raina

Gerald Michalak

Kenneth Alan c/o Qualcomm Incorporated Dockser

Victor Robert Augsburg

Brian Michael Stempel

Michael Scott Mcilvaine

Michael William Morrow

Gerald P Michalak

Steven M Millendorf

Allocating power between multiple central processing units (CPUs) in a multi-CPU processor based on total current availability and individual CPU quality-of-service (QoS) requirements is disclosed. Current from a power rail is allocated to CPUs by a global current manger (GCM) circuit related to performance criteria set by CPUs. The CPUs can request increased current allocation from the GCM circuit, such as in response to executing a higher performance task. If the increased current allocation request keeps total current on the power rail within its maximum rail current limit, the GCM circuit approves the request to allow the CPU increased current allocation. This can allow CPUs executing higher performance tasks to have a larger current allocation than CPUs executing lower performance tasks without the maximum rail current limit being exceeded, and without having to necessarily lower voltage of the power rail, which could unnecessarily lower performance of all CPUs.

Allocating power between multiple central processing units (CPUs) in a multi-CPU processor based on total current availability and individual CPU quality-of-service (QoS) requirements

Adaptive voltage modulation circuits for adjusting supply voltage to reduce supply voltage droops and minimize power consumption are provided. In one aspect, an adaptive voltage modulation circuit detects a supply voltage droop by detecting when a supply voltage falls below a droop threshold voltage, and adjusts a clock signal provided to a load circuit in response to a supply voltage droop. The adaptive voltage modulation circuit keeps a count of the number of clock signal cycles during which the supply voltage is below the droop threshold voltage. The adaptive voltage modulation circuit increases the supply voltage in response to the count exceeding an upper threshold value, and decreases the supply voltage in response to the count being less than a lower threshold value at an end of a defined period. The adaptive voltage modulation circuit can reduce the time a load circuit operates with reduced frequency while minimizing power consumption.

Adaptive voltage modulation circuits for adjusting supply voltage to reduce supply voltage droops and minimize power consumption

The disclosure generally relates to dynamic clock and voltage scaling (DCVS) based on program phase. For example, during each program phase, a first hardware counter may count each cycle where a dispatch stall occurs and an oldest instruction in a load queue is a last-level cache miss, a second hardware counter may count total cycles, and a third hardware counter may count committed instructions. Accordingly, a software/firmware mechanism may read the various hardware counters once the committed instruction counter reaches a threshold value and divide a value of the first hardware counter by a value of the second hardware counter to measure a stall fraction during a current program execution phase. The measured stall fraction can then be used to predict a stall fraction in a next program execution phase such that optimal voltage and frequency settings can be applied in the next phase based on the predicted stall fraction.

Method and apparatus for dynamic clock and voltage scaling in a computer processor based on program phase

Systems and methods for operating a processor include determining confidence levels, such as high, low, and medium confidence levels, associated with in-flight branch instructions in an instruction pipeline of the processor, based on counters used for predicting directions of the in-flight branch instructions. Numbers of in-flight branch instructions associated with each of confidence levels are determined. A weighted sum of the numbers weighted with weights corresponding to the confidence levels is calculated and the weighted sum is compared with a threshold. A throttling signal may be asserted to indicate that instructions are to be throttled in a pipeline stage of the instruction pipeline based on the comparison.

Dynamic pipeline throttling using confidence-based weighting of in-flight branch instructions

Delays due to waiting for operands that will not be used by a select operand instruction, are alleviated based on an early recognition that such operand data is not required in order to complete the processing of the select operand instruction. At appropriate points prior to execution, determinations are made regarding a selection criterion or criteria specified by the select operand instruction, conditions that affect the selection criteria, and the availability of operands. A hold circuit uses the determinations to control the activation and release of a hold signal that controls processor pipeline stalls. A stall required to wait for operand data is skipped or a stall is terminated early, if the selected operand is available even though the other operand, that will not be used, is not available. A stall due to waiting for operands is maintained until the selection criteria is met and the selected operand is fetched and made available.

Early conditional selection of an operand

Circuits, systems, and methods for monitoring a power supply voltage and determining if the power supply voltage has drooped are disclosed. In one embodiment, a voltage monitoring circuit is provided and configured to determine if the power supply voltage supplied to a functional circuit has drooped. When no droop of the power supply voltage is detected, the voltage monitoring circuit is configured to provide an indication to the functional circuit to operate in a first mode. When droop of the power supply voltage is detected, the voltage monitoring circuit is configured to provide an indication to the functional circuit to operate in a second mode. In this manner, operating margin in the power supply may be reduced since the functional circuit may be configured to properly operate when a voltage droop of the power supply voltage occurs.

Circuits, systems and methods to detect and accommodate power supply voltage droop

Automatic calibration circuits for operational calibration of critical-path time delays in adaptive clock distribution systems, and related methods and systems, are disclosed. The adaptive clock distribution system includes a tunable-length delay circuit to delay distribution of a clock signal provided to a clocked circuit, to prevent timing margin degradation of the clocked circuit after a voltage droop occurs in a power supply supplying power to the clocked circuit. The adaptive clock distribution system also includes a dynamic variation monitor to reduce frequency of the delayed clock signal provided to the clocked circuit in response to the voltage droop in the power supply, so that the clocked circuit is not clocked beyond its performance limits during a voltage droop. An automatic calibration circuit is provided in the adaptive clock distribution system to calibrate the dynamic variation monitor during operation based on operational conditions and environmental conditions of the clocked circuit.

Automatic calibration circuits for operational calibration of critical-path time delays in adaptive clock distribution systems, and related methods and systems

Synthesizing intermediate performance levels in integrated circuits, and related processor systems, methods, and computer-readable media are disclosed. In one embodiment, a synthesized performance level setting circuit receives an input indicating a synthesized performance mode. The circuit generates a power source selection output to select a first power source providing power to an integrated circuit functional block at a first voltage level, and generate a clock frequency setting output to select a first clock frequency associated with the first voltage level to clock the functional block, for a first predefined time interval. The circuit also generates the power source selection output to select a second power source to provide power at a second voltage level lower than the first voltage level, and generate the clock frequency setting output to select a second clock frequency associated with the second voltage level to clock the functional block, for a second predefined time interval.

Synthesizing intermediate performance levels in integrated circuits, and related processor systems, methods, and computer-readable media

Methods and apparatus for voltage scaling are provided. In an example, an operational limit of a processor is determined by varying a supply voltage to force a processor interrupt fault and/or a processor reset. A clock frequency and the supply voltage can be maintained substantially constant for a time duration. If these operational parameters do not force the processor interrupt fault and/or the processor reset, the supply voltage is varied again, and the clock frequency and the supply voltage are maintained substantially constant for a second time duration. The variation continues until initiation of the processor interrupt fault and/or the processor reset, at which time least one of a clock frequency, the supply voltage, and a temperature are recorded as an operational limit. After determining the operational limit, the supply voltage is adjusted to within the operational limit.

Methods and apparatus for voltage scaling

Adaptive voltage scalers (AVSs), systems, and related methods are disclosed. The AVSs are configured to adaptively adjust voltage levels powering a functional circuit(s) based on target operating frequencies and delay variation conditions to avoid or reduce voltage margin. In one embodiment, the AVS includes an AVS database. The AVS database can be configured to store voltage levels for various operating frequencies of a functional circuit(s) to avoid or reduce voltage margin. The AVS database allows rapid voltage level decisions. The voltage levels stored in the AVS database may be initial, minimum, learned, populated, explored, backed out, temperature-based, and/or age-based voltage levels according to disclosed embodiments to further avoid or reduce voltage margin. An AVS module may be a software-based module that consults the AVS database to make voltage level decisions. Providing the AVS module as a software-based module may allow flexibility in configuring the AVS module and/or the AVS database.

Adaptive voltage scalers (AVSs), systems, and related methods

Adaptive voltage scalers (AVS), systems, and related methods

Different software applications may use a set of instructions having critical timing paths less than a worst case critical timing path of a processor complex. For such applications, a supply voltage may be reduced while still maintaining the clock frequency necessary to meet the application's performance requirements. In order to reduce the supply voltage, an adaptive voltage scaling method is used. A critical path is selected from a plurality of critical paths for analysis on emulation logic to determine an attribute of the selected critical path during on chip functional operations. The selected critical path is representative of the worst case critical path to be in operation during a program execution. During on-chip functional operations, a voltage is controlled in response to the attribute, wherein the voltage supplies power to a power domain associated with the plurality of critical paths. The reduction in voltage reduces power drain based on instruction set usage allowing battery life to be extended.

Method and apparatus for adaptive voltage scaling based on instruction usage

A processor includes a conditional branch instruction prediction mechanism that generates weighted branch prediction values. For weakly weighted predictions, which tend to be less accurate than strongly weighted predictions, the power associating with speculatively filling and subsequently flushing the cache is saved by halting instruction prefetching. Instruction fetching continues when the branch condition is evaluated in the pipeline and the actual next address is known. Alternatively, prefetching may continue out of a cache. To avoid displacing good cache data with instructions prefetched based on a mispredicted branch, prefetching may be halted in response to a weakly weighted prediction in the event of a cache miss.

Power efficient instruction prefetch mechanism

Growing community of inventors

Raleigh, NC, United States of America

Jeffrey Todd Bridges