This repository contains selected engineering reference notes covering Ethernet behavior across embedded and automotive systems.
The material is maintained as an engineering notebook, not as a tutorial, textbook, or protocol specification.
Its purpose is to preserve working understanding – the physical behavior, invariants, failure modes, and architectural patterns required to reason correctly about Ethernet-based systems, particularly where the PHY layer, bring-up sequencing, and system integration dominate complexity.
This repository is intended to grow as a long-term Ethernet knowledge base, spanning both conventional and automotive environments.
Topics include, but are not limited to:
- Ethernet framing and encapsulation behavior
- MAC-PHY separation and responsibilities
- PHY-layer behavior and constraints
- embedded Ethernet bring-up principles
- automotive Ethernet PHY fundamentals (e.g. single-pair Ethernet)
- link initialization and training concepts
- debugging methodology and failure interpretation
- Ethernet used as a system communication transport
- interaction with other in-vehicle networks (e.g. CAN)
Concrete examples within the repository are drawn from real hardware bring-up and system experiments, but the underlying principles are not limited to any single microcontroller, PHY, or vendor.
- An engineering reference for Ethernet systems
- A record of system-level reasoning and failure analysis
- A place to consolidate mental models that are difficult to reconstruct from specifications alone
- Focused on understanding why systems behave the way they do
The repository currently organizes material into a small number of focused engineering documents, each serving a distinct purpose:
-
ethernet-foundations.md
Physical and logical behavior of Ethernet on a local area network -
stm32-ethernet-bringup.md
Practical bring-up rules and failure modes observed during embedded Ethernet integration -
ethernet-debugging-and-tools.md
Interpretation of packet captures, filtering behavior, and debugging tools -
ethernet-as-a-transport.md
System-level use of Ethernet as a communication transport within embedded architectures
Additional documents may be added as the scope expands, particularly in areas related to automotive Ethernet PHY behavior and system startup sequencing.
Author: Percival Segui
Independent engineering project record
This repository contains original reference material intended for educational and personal engineering use.