Use ENET_SetMII() function without disabling Ethernet MAC

[ombra32]

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

[jeremyzhou]

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

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[ombra32]

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

[jeremyzhou]

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

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