SoC Time Domain Synchronization via Third-Domain Timestamp Comparison

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Solution Overview

Problem

Existing systems-on-chip face challenges in synchronizing different time domains, particularly those defined by PTM and PTP protocols, without modifying communication interfaces to maintain compatibility with third-party devices.

Innovation Solution

A method synchronizes time domains by detecting periodic triggering events, acquiring current timestamp values, and comparing differential durations to generate synchronization commands, leveraging existing timestamp information without modifying the time domains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If different communication protocols (PTM for PCIe, PTP for Ethernet) are used to share time information, then each interface can maintain its own time domain independently, but the time domains become incompatible and cannot be directly synchronized

Engineering Contradiction:
Improvecompatibility with third-party devicesVSAvoidtime domain synchronization
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent introduces a third time domain as an intermediary reference frame to compare and synchronize the first and second time domains. This mediator time domain allows indirect comparison of timestamp values from different protocols without requiring direct compatibility between them, thus maintaining protocol independence while achieving synchronization.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent adds a temporal dimension by introducing a third time domain that serves as a reference frame. Instead of trying to directly align two incompatible time domains, the solution transitions to a higher-dimensional comparison space where all three time domains can be referenced against a common baseline, enabling synchronization through differential duration measurement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If modifications are introduced into communication interfaces to synchronize time domains, then time domain synchronization can be achieved, but compatibility with third-party devices is compromised

Engineering Contradiction:
Improvetime domain synchronizationVSAvoidcompatibility with third-party devices
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system uses its own internal third time domain and timestamp comparison mechanism to achieve synchronization, without requiring external modifications to the communication interfaces. The interfaces continue to operate independently using their native protocols, while the synchronization function serves itself by measuring differential durations internally.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The synchronization functionality is extracted from the communication interfaces themselves and implemented as a separate function using a third time domain. This separates the time domain synchronization task from the protocol-specific interface operations, allowing interfaces to remain unmodified and compatible while achieving synchronization through the extracted comparison mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

3Measurement precision

If timestamp values from different time domains are directly compared, then synchronization can be attempted, but the different encodings and protocols make direct comparison inaccurate

Engineering Contradiction:
Improvetime synchronization precisionVSAvoidtime domain compatibility
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Instead of trying to convert or adapt timestamp values from different protocols to a common format, the patent inverts the approach by comparing the differential durations between timestamp acquisitions in a neutral third time domain. This reverse comparison method avoids the complexity of protocol conversion while achieving precise synchronization measurement.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the measurement parameter from direct timestamp value comparison to differential duration comparison. By measuring the time difference between successive timestamp acquisitions in the third time domain, the system transforms the synchronization problem into a parameter change that is protocol-independent and directly comparable across different time domains.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4033680B1Method for time field synchronisation of a chip-based system.
Publication Date: 2026.02.25 STMICROELECTRONICS (GRENOBLE 2) SAS
  • EP4033680B1 patent drawingFigure 1A~1B
  • EP4033680B1 patent drawingFigure 1C~1D
  • EP4033680B1 patent drawingFigure 2

AI summary

The method for synchronizing a first time domain (DMN1) with a second time domain (DMN2) of a system-on-chip (SoC) comprises: - detecting at least one periodic triggering event (TRG) generated in the first time domain (DMN1), the second time domain (DMN2) or in a third time domain (DMN3); - acquiring, at the times of said at least one triggering event (TRG), current timestamp values ​​(TS1, TS2) representative of the instantaneous states of the time domain(s) other than the triggering time domain; - comparing, in the third time domain (DMN3), between differential durations between current timestamp values ​​respectively acquired successively (PPS_1, PPS_2); and - synchronizing the second time domain (DMN2) with the first time domain (DMN1), from said comparison.