Hello @vinmotion ,
It seems that S32K388 might not be the best choice for EtherCAT, because EtherCAT typically requires a dedicated EtherCAT Slave Controller (ESC) - this is a hardware block that handles on-the-fly frame processing and distributed clocks. S32K388 does not have an integrated ESC, so implementing EtherCAT would require an external controller or a software stack with strict timing constraints.
EtherCAT is generally a domain of the i.MX family, and NXP provides solutions with integrated ESC. For example, the i.MX RT1180 includes a built-in EtherCAT two-port slave controller, making it much easier to implement EtherCAT without additional hardware.
Please check this application note related to i.MX RT1180 and EtherCAT:
https://www.nxp.com/docs/en/application-note/AN14155.pdf
Best regards,
Pavel