FPGA Dynamic Voltage Scaling Using Critical-Path Replica Circuits

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Integrated circuits, particularly field programmable gate arrays (FPGAs), face challenges in managing power consumption and performance across different regions due to varying critical paths, leading to inefficient power usage and potential thermal issues.

Innovation Solution

The implementation of synthetic tunable replica circuits (STRCs) that mimic critical paths within the FPGA, allowing for dynamic voltage and frequency scaling, which enables regions to operate at lower voltages and frequencies without compromising performance, and also detects anomalies and improves end-of-life parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the clock frequency and voltage are maintained at nominal levels across all regions, then the performance and reliability of the integrated circuit are ensured, but the power consumption increases and thermal issues arise

Engineering Contradiction:

Improvecircuit performanceVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The integrated circuit is divided into multiple regions, each with its own critical path analysis and independent STRC. This allows each region to be managed separately with customized voltage and frequency settings, enabling power reduction in non-critical regions while maintaining performance in critical regions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the integrated circuit are assigned different operating characteristics based on their specific critical path requirements. Regions with shorter critical paths can operate at lower voltages and frequencies, while regions with longer critical paths maintain higher settings, optimizing the overall power-performance balance.

Inventive Principle:

Principle #3Local quality

2Use of energy by moving object

If the clock frequency is reduced to lower power consumption, then the power savings are achieved, but the performance and speed of the integrated circuit deteriorate

Engineering Contradiction:

Improvepower consumptionVSAvoidcircuit speed

Core Design Contradiction:

Use of energy by moving objectVSSpeed

Solution Approach 1:

The STRC dynamically adjusts its operation based on real-time monitoring of the critical path behavior. The replica circuit can change its operating frequency and voltage levels adaptively, allowing the system to optimize power consumption while maintaining the necessary performance levels based on actual circuit conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The STRC continuously monitors the critical path delay and uses this feedback to adjust its own operation and provide guidance for optimizing the main circuit's voltage and frequency settings. This closed-loop control ensures that performance requirements are met while minimizing power consumption.

Inventive Principle:

Principle #23Feedback

3Use of energy by moving object

If synthetic tunable replica circuits are inserted into unused logic, then the power consumption is reduced through dynamic scaling, but the device complexity increases

Engineering Contradiction:

Improvepower consumptionVSAvoidcircuit complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

Instead of directly monitoring and controlling the complex critical paths of the main circuit, a simplified replica circuit (STRC) is created that mimics the critical path behavior. This copy allows for easier measurement and control, reducing the overall system complexity while still enabling dynamic power management.

Inventive Principle:

Principle #26Copying

4Use of energy by moving object

If the voltage is reduced to save power, then the energy consumption decreases, but the signal integrity and operational reliability may be compromised

Engineering Contradiction:

Improvepower consumptionVSAvoidsignal integrity

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

Before reducing the voltage to save power, the STRC performs preliminary measurements and calculations to determine the safe voltage reduction threshold. This preliminary action ensures that the voltage is reduced only to levels that maintain signal integrity and operational reliability, preventing compromise of circuit function.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11334696B2Systems and methods for dynamic voltage and frequency scaling in programmable logic devices

Publication Date: 2022.05.17 ALTERA CORP

AI summary

A system, may include a processor configured to receive circuit design data, identify one or more critical paths of the circuit design data, and generate one or more synthetic tunable replica circuits (STRCs) that may mimic the one or more critical paths. The processor may then compile the circuit design data and the one or more STRCs into program data. The system may also include an integrated circuit including a control circuit that may receive the program data from the processor, program a plurality of programmable logic regions of the integrated circuit to implement the circuit design data and the one or more STRCs, and adjust one or more operating parameters of at least one of the plurality of programmable logic regions based on the one or more STRCs.