Ethernet MAC-to-MAC connection possible for ESP32?

[Adrian]

Hello everyone,

I was wondering if it would be possible to directly attach the ESP32 to an ethernet MAC interface, e.g. a switch like KSZ9896 ?
It would greatly reduce BOM cost and current consumption if we could remove the PHY layer in the connection from the ESP to the Ethernet Switch.

Obviously there are no drivers in ESP-IDF for this. What do I have to do to write such a driver to enable the ESP-MAC to directly communicate with another Ethernet MAC without PHY layer involvement?

Many thanks in advance!

[ESP_Sprite]

As far as I know, the MAC in the ESP32 should be capable of this, so at least wrt hardware support you should be fine.

[Adrian]

That sounds good. And are there any coding examples?
I tried to understand the LAN8720 driver from ESP-IDF, but it seems quite strongly intertwined with the serial management interface (MDIO/MDC signals), which I don't need for that purpose.

[ESP_Sprite]

No, likely not, you'd have to write your own driver (or modify an existing one).