Even though it may sound a little impractical for contexts where the size of the whole system is comparable to an RJ-45 connector, Ethernet is still the most reliable and the fastest channel of communication available to integrate in embedded systems.
Many Cortex-M microcontrollers are equipped with one Ethernet MAC controller, which must be integrated with an external PHY. Other link-layer protocols implement the same mechanism for link-layer addressing, consisting of a 14-byte preamble, attached to each packet transmitted, indicating the source and destination link addresses and the type of payload contained in the packet being transported. The addresses are rewritten every time a packet is routed toward an Ethernet-like interface ...
