Why RX_ER signal is optional in RMII mode of EMAC

[Shashanksd07]

Hi,

I am currently working on EMAC and I am a beginner ,So I want to know that why RX_ER is made optional for connection and if it made optional then how the errors are detected during reception.

@STea

@LCE

[LCE]

As far as I understand: to off-load the STM32, and the STM32's RMII just doesn't do anything with it.

See this:

https://community.st.com/t5/stm32-mcus-products/ethernet-rmii-rx-error/td-p/440696

The link status should be checked regularly by reading the PHY registers.

When I look at the LAN8742 datasheet, it seems that RX_ER shows an error on the lowest hardware layer. 
If that happens, there's some really bad things going on...