topic Re: Use ENET_SetMII() function without disabling Ethernet MAC in i.MX RT Crossover MCUs

Use ENET_SetMII() function without disabling Ethernet MAC

ombra32 — Wed, 15 Jun 2022 09:07:59 GMT

Hi,

I need to dynamically change MAC controller speed and duplex, based on values auto-negotiated by PHY at each link up.

In iMXRT1176 SDK there is a function named ENET_SetMII(), created exactly with that purpose:

/*! * brief Sets the ENET MII speed and duplex. * * This API is provided to dynamically change the speed and dulpex for MAC. * * param base ENET peripheral base address. * param speed The speed of the RMII mode. * param duplex The duplex of the RMII mode. */ void ENET_SetMII(ENET_Type *base, enet_mii_speed_t speed, enet_mii_duplex_t duplex) {

I've tried it on my code, and it works like a charm!

But iMXRT1170 Reference Manual states that TCR->FDEN register (changed by ENET_SetMII() function) can be modified only with ECR->ETHEREN = 0 (Ethernet MAC disabled).

So, now the question is: is really safe to use ENET_SetMII() function to dynamically change speed and duplex of MAC controller, without disabling it?

Best regards,

Marco

Re: Use ENET_SetMII() function without disabling Ethernet MAC

jeremyzhou — Fri, 17 Jun 2022 06:59:33 GMT

Hi，
Thank you for your interest in NXP Semiconductor products and for the opportunity to serve you.
1) Is really safe to use ENET_SetMII() function to dynamically change speed and duplex of MAC controller, without disabling it?
-- No, I'm afraid not, it's a risk to do it.
Have a great day,t
TIC

-------------------------------------------------------------------------------
Note:
- If this post answers your question, please click the "Mark Correct" button. Thank you!

- We are following threads for 7 weeks after the last post, later replies are ignored
Please open a new thread and refer to the closed one, if you have a related question at a later point in time.
-------------------------------------------------------------------------------

Re: Use ENET_SetMII() function without disabling Ethernet MAC

ombra32 — Thu, 23 Jun 2022 07:54:03 GMT

Ok, so what is the best suggested way to manage ENET MAC after PHY re-link?

Re: Use ENET_SetMII() function without disabling Ethernet MAC

jeremyzhou — Fri, 24 Jun 2022 09:40:57 GMT

Hi，
Thanks for your reply.
1) So what is the best suggested way to manage ENET MAC after PHY re-link?
-- It seems like that it needs to reInitialize the ENET module.
Have a great day,
TIC

-------------------------------------------------------------------------------
Note:
- If this post answers your question, please click the "Mark Correct" button. Thank you!