FPGA Ring Oscillator Lifetime Monitoring for Accurate Aging Prediction

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Solution Overview

Problem

Existing methods for predicting the lifetime of Field-Programmable Gate Array (FPGA) devices are inaccurate and resource-intensive, leading to premature failure and increased maintenance costs, which can be safety-critical.

Innovation Solution

A hardware microservice on an FPGA SoC uses a ring oscillator, on-chip timer, diagnostic memory, and sensors to measure device health by comparing timing, temperature, and voltage against predefined reference values, allowing efficient and accurate determination of remaining lifetime without permanent resource consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If hardwired logic is used to measure device health, then voltage and temperature can be monitored, but additional chip area is consumed and prediction accuracy remains insufficient

Engineering Contradiction:
Improvedevice health prediction accuracyVSAvoidchip area
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The ring oscillator serves multiple functions: it acts as both a timing reference and an aging sensor. The same logic elements that perform normal computational functions also measure device aging through timing delays, eliminating the need for dedicated aging measurement hardware and thus avoiding additional chip area consumption while improving measurement accuracy

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The device uses its own operational logic elements to measure its own aging. The ring oscillator's timing delay naturally increases with device aging, and this self-induced change is captured and used as the measurement signal, eliminating the need for external or separate measurement mechanisms

Inventive Principle:
Principle #25Self-service

2Measurement precision

If statistical estimates are used for device lifetime, then prediction is simple, but the estimates can be far off from real lifetime

Engineering Contradiction:
Improvelifetime prediction accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces statistical estimation methods with a physical measurement approach. Instead of using complex statistical models that require extensive data collection and processing, the system directly measures the physical aging effect through ring oscillator timing delays, providing accurate predictions with a simple and direct measurement mechanism

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system monitors changes in the ring oscillator's timing delay parameter, which naturally changes with device aging. By tracking this physical parameter's evolution over time and comparing it to reference values, the system achieves accurate lifetime prediction without complex statistical analysis

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If device health monitoring is implemented continuously, then accurate lifetime determination is achieved, but FPGA resources are permanently consumed

Engineering Contradiction:
Improveremaining lifetime determination accuracyVSAvoidFPGA resource availability
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The health monitoring microservice is executed periodically rather than continuously. The system can dynamically allocate FPGA resources to run the monitoring service at scheduled intervals, allowing full resource utilization between measurements while achieving accurate lifetime determination through periodic assessments

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically configures FPGA resources based on monitoring needs. The ring oscillator and timing logic are activated only when health measurements are required, and resources are reconfigured or released for other uses between measurements, maintaining measurement accuracy while optimizing resource productivity

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Accurately determines the remaining effective lifetime of an FPGA, enabling timely maintenance and reducing resource usage, thus minimizing maintenance cycles and potential safety risks.

Implementation Method 1

the ageing of the device is measured with ring oscillators delay time against reference values

Methodology Applied
Scientific EffectRing oscillator delay:

Data Source

PatentEP4664123A1Method and electronic device to determine the remaining effective lifetime of the electronic device
Publication Date: 2025.12.17 SIEMENS AG
  • EP4664123A1 patent drawingFigure 1
  • EP4664123A1 patent drawingFigure 2~3
  • EP4664123A1 patent drawing

AI summary

Method to determine the remaining effective lifetime of an electronic device (DEV), which is configured to execute a hardware microservice (HW-MS), the device (DEV) comprising a ring oscillator (RO), an on-chip timer (T), at least one voltage sensor (VS), at least one temperature sensor (TS), a diagnostic memory (EDD DB), a device health reference memory (DHRR), a delay measurement module (DMU), a device health diagnostic module (DHDU), at least one interface (IC, HPSF-IF, LAN) to connect the on-chip timer (T), the diagnostic memory (EDD DB), the reference memory (DHRR), the at least one voltage sensor (VS), the at least one temperature sensor (TS) and the ring oscillator (RO) with the delay measurement unit (DMU) and/or the device health diagnostic unit (DHDU), wherein the hardware microservice is configured to execute following steps: a) capture a voltage (VOLT), b) receiving reference values regarding the device voltage (VOLT), the temperature (TEMP), the timing (TIME) from the reference memory (DHRR), c) receiving threshold values regarding the device voltage (VOLT), the temperature (TEMP), the timing (TIME) from the diagnostic memory (EDD DB), d) determining the remaining effective lifetime of the electronic device (DEV) by comparing the timing delay (TIME) with the received reference values and the received threshold values, e) receiving threshold values regarding the device voltage (VOLT), the temperature (TEMP), the timing (TIME) from the diagnostic memory (EDD DB), wherein the threshold values are predefined and stored within the diagnostic memory (EDD DB), f) determining the remaining effective lifetime of an electronic device (DEV) by comparing the received reference values and the received threshold values.