Processor Core Deactivation via Sub-Retention Voltage

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Solution Overview

Problem

Conventional techniques for deactivating processor cores in multi-core processing systems result in significant leakage current due to the application of boot voltage, leading to continued power consumption despite deactivation.

Innovation Solution

Applying a voltage less than the retention voltage, typically zero volts, to the processor core, and using a voltage controller to tie voltage inputs together, along with clock gating or reducing clock frequency, to effectively deactivate the core.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If boot voltage is applied to deactivate a processor core, then basic operations can still be performed, but significant leakage current occurs causing continued power consumption

Engineering Contradiction:

Improveprocessor core deactivationVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent changes the voltage parameter from boot voltage to a voltage below retention voltage, fundamentally altering the electrical state of the processor core to achieve complete deactivation while preserving silicon state. This parameter change eliminates leakage current and stops power consumption.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

Instead of applying a reduced voltage (boot voltage) to deactivate the core, the patent applies the opposite approach by using a voltage significantly below retention voltage, effectively inverting the conventional deactivation method to achieve complete power shutdown.

Inventive Principle:

Principle #13The other way round (Inversion)

2Adaptability or versatility

If boot voltage is applied to deactivated processor core, then basic operations and instruction execution are permitted, but leakage current increases significantly

Engineering Contradiction:

Improveprocessor core functionalityVSAvoidleakage current

Core Design Contradiction:

Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent fundamentally changes the voltage parameter from boot voltage to below-retention voltage, which eliminates the harmful leakage current while maintaining the ability to preserve silicon state for future activation.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the potentially harmful effect of voltage application into a beneficial outcome by using a voltage below retention voltage, which not only eliminates leakage current but also preserves the silicon state for future use, turning what could be harmful into a beneficial deactivation method.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If normal operating voltage is applied to deactivated processor core, then full functionality is maintained, but power consumption increases

Engineering Contradiction:

Improveprocessor core performanceVSAvoidpower consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent applies a voltage parameter change from normal operating voltage to below-retention voltage, which reduces power consumption to minimal levels while preserving the silicon state, allowing the core to be deactivated without sacrificing future activation capability.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS7856562B2Selective deactivation of processor cores in multiple processor core systems

Publication Date: 2010.12.21 ADVANCED MICRO DEVICES INC

AI summary

A method includes applying a voltage to a first processor core of a plurality of processor cores to deactivate the first processor core, the voltage less than a retention voltage of the first processor core. The application of the voltage can be in response to a software setting. The software setting can be configured via a user input, a software application, an operating system, or a BIOS setting. Alternately, the application of the voltage can be in response to a permanent hardware setting, such as the state of a fuse associated with the first processor core.