HMC Controller Wait Mode for Low Power Transitions

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Solution Overview

Problem

Existing HMC systems face power consumption issues due to high-speed serial links remaining active for synchronization, leading to packet loss when switching to sleep mode, and performance degradation from lengthy mode switching times.

Innovation Solution

Implementing a CPU and HMC side controller with a wait mode that checks buffer emptiness before switching to sleep mode, using check packets to ensure no packet loss and minimizing performance degradation by adjusting link states based on bandwidth calculations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the high-speed serial link remains active for synchronization, then link stability is maintained, but power consumption increases

Engineering Contradiction:

Improvelink stabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The link dynamically switches between active mode and sleep mode based on data transmission requirements. When no data is transmitted for a predetermined period, the link transitions to sleep mode to reduce power consumption while maintaining the ability to quickly resume active mode when needed.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the link by adjusting the synchronization signal transmission frequency and timing. During sleep mode, the link maintains basic synchronization with reduced activity, allowing power savings while preserving link stability for quick reactivation.

Inventive Principle:

Principle #35Parameter changes

2Use of energy by moving object

If the link switches to sleep mode to reduce power consumption, then power efficiency improves, but packet loss occurs

Engineering Contradiction:

Improvepower efficiencyVSAvoidpacket transmission reliability

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

Before switching to sleep mode, the system transmits a wake-up packet to ensure any pending data is flushed through the link. This preliminary action prevents packet loss by clearing the buffer before the link enters low-power state.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses acknowledgment packets and buffer status monitoring to provide feedback about data transmission state. This feedback mechanism ensures that the link only enters sleep mode when it is safe to do so, preventing packet loss by confirming all data has been transmitted.

Inventive Principle:

Principle #23Feedback

3Use of energy by moving object

If the link switches between active and sleep modes, then power consumption is reduced, but mode switching time degrades performance

Engineering Contradiction:

Improvepower consumptionVSAvoidmode switching time

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The system enters sleep mode after a predetermined period of no data transmission, creating a periodic pattern of active and sleep states. This predictable timing allows the system to optimize the balance between power savings and performance impact.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system uses wake-up packets and priority handling to rush through the mode transition process as quickly as possible. By prioritizing the resumption of active mode when data transmission is needed, the system minimizes the performance impact of mode switching.

Inventive Principle:

Principle #21Skipping (Rushing through)

4Use of energy by moving object

If all links switch to sleep mode simultaneously, then power consumption is maximally reduced, but link availability decreases

Engineering Contradiction:

Improvepower consumptionVSAvoidlink availability

Core Design Contradiction:

Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The system segments the link group into multiple independent links that can operate in different modes simultaneously. This allows some links to remain active while others enter sleep mode, providing both power savings and maintained availability for different data streams.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each link is independently controlled with its own sleep/active state based on its specific data transmission needs. This local control allows optimal power management for each link while maintaining overall system availability through differentiated link states.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS11243600B2HMC control device and method of CPU side and HMC side for low power mode, and power management method of HMC control device

Publication Date: 2022.02.08 INDUSTRY UNIVERSITY COOPERATION FOUNDATION HANYANG UNIVERSITY

AI summary

Disclosed are an HMC controller and a controlling method on a CPU side and an HMC side for a low power mode, and a recording medium related thereto. The CPU side HMC controller includes a plurality of link units, each of which includes a link master for storing request packets of a CPU in a request buffer and transmitting the request packets to an HMC side HMC controller in the order that they are stored; and a link slave for storing the request packets received from the HMC side HMC controller in a response buffer and transmitting the request packets to the CPU in the order that they are stored.