Adaptive Power Ramp Control for Microprocessor Voltage Droop Mitigation

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Solution Overview

Problem

High-frequency voltage droops in microprocessors due to inductance in power distribution networks and sudden power fluctuations lead to critical path timing failures, with traditional approaches either ineffective or requiring significant power and performance sacrifices.

Innovation Solution

An adaptive power ramp control system that monitors core power and power ramp conditions to determine imminent voltage droops, generating stall control signals to reduce power usage and mitigate voltage fluctuations by stalling functional units according to predefined patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional approaches increase operational margins (voltage guardbands) to avoid critical path timing failures, then reliability is improved, but power consumption increases and performance decreases

Engineering Contradiction:

Improveavoid critical path timing failuresVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The APRC circuit performs preliminary detection of power ramp conditions and predicts imminent voltage droops before they occur. By detecting the power ramp slope and anticipating voltage droop events in advance, the system can take preventive stalling actions on functional units, avoiding timing failures without needing to maintain large voltage guardbands throughout operation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system dynamically changes operational parameters by adjusting the activity state of functional units based on detected power ramp conditions. The APRC circuit monitors power parameters and modulates the operational state (active/stalled) of functional units in response, thereby adapting power consumption and performance in real-time to prevent timing failures only when necessary.

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If traditional approaches suppress voltage fluctuations to allow smaller voltage guardbands, then power consumption is reduced, but the approaches are effective only in limited frequency ranges

Engineering Contradiction:

Improvepower consumptionVSAvoidfrequency range effectiveness

Core Design Contradiction:

Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The APRC circuit implements dynamic adaptation to varying operating conditions by continuously monitoring power ramp slopes and adjusting control decisions in real-time. The system adapts its behavior based on the detected power conditions and can respond to a wide range of frequencies, making it effective across different operating scenarios rather than being limited to a specific frequency range.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system employs feedback mechanisms where the APRC circuit continuously monitors power ramp conditions and uses this information to control the stalling of functional units. The feedback loop detects power parameters, determines control decisions, and adjusts functional unit operation accordingly, enabling effective suppression of voltage fluctuations across varying frequency ranges.

Inventive Principle:

Principle #23Feedback

3Productivity

If microprocessor complexities increase to improve performance, then processing capability is improved, but dI/dt and L increase causing increasingly severe high-frequency voltage droops

Engineering Contradiction:

Improveprocessing capabilityVSAvoidhigh-frequency voltage droops

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The APRC circuit acts as an intermediary control mechanism between the power distribution network and the functional units. It monitors the power ramp conditions caused by complex microprocessor operation and mediates by controlling the activity of functional units, thereby preventing the harmful effects of high dI/dt and inductance from causing severe voltage droops.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The microprocessor system performs self-service by incorporating the APRC circuit within the processor itself, enabling it to autonomously monitor its own power conditions and regulate its functional units to prevent voltage droops. The system self-regulates without requiring external intervention, maintaining stability despite increasing complexity.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS9710042B2Adaptive microprocessor power ramp control

Publication Date: 2017.07.18 ORACLE INT CORP

AI summary

Embodiments of the invention provide adaptive power ramp control (APRC) in microprocessors. One implementation of the APRC can compute a present core power and a present power ramp condition in the microprocessor, for example, to determine whether the present power is in a particular predefined control zone and whether the present power ramp is greater than a predefined threshold for that control zone. Those determinations can indicate a likelihood of an imminent, undesirable power ramp condition and can inform entry into a control mode. The APRC can generate an appropriate stall control signal in response to its present control mode, and the stall control signal can stall operation of at least one functional unit of the microprocessor according to a predefined stall pattern. This can effectively combat the imminent power ramp condition by reducing the power usage of the microprocessor.