Operating GETH RMII of TC375 / TC377 in Mac to Mac mode

[Coder]

Hi !

I want to connect a TC37x to a ublox NINA-W15 Bluetooth/WiFi device using the RMII. This requires a so called "Mac to Mac" connection where the TXD0/1 and RXD0/1 as well as TXEN and CRSDV are cross-wired.

This configuration is supported by the ublox - but how about the Aurix?

I could not find this topic addressed in the Aurix user manual, so any advice would be highly appreciated.

[Nambi · Accepted solution]

Hi,

This is a feature of the interface on PCB. Connecting TX of AURIX to RX of ublox is a schematic topic. The important point on that interface option is who provides the 50MHz REFLCK for the RMII interface. Typically the PHY is doing that. AURIX is not providing that option. So if the ublox can not do this, a 50MHz oscillator could be used.

Best Regards.