[En-Nut-Discussion] STM32: Standard Speed for EMAC GPIO Pins

Henrik Maier hmnews at proconx.com
Wed Feb 6 13:16:20 CET 2013

On 6/02/2013 8:41 PM, Uwe Bonnes wrote:
> probably the GPIO pin setting got more complicated after Ulrich and me
> worked on the STM32 EMAC driver. A quick look now reveals that we don't set
> GPIO_CFG_SPEED_xxx  and so get  GPIO_CFG_SPEED_MED as default, or 25 (Medium
> Speed) for the F2. I think the RMII interface needs 50 MHz.
> Hendrik, can you have a look?

I just was about to commit a new st_emac version which has the speed 
setting set to 25MHz for MII interface and 50 MHz for RMII. For EMC 
reasons it is better to use the lowest clock required to do the job I 
think. And you are correct RMII needs 50 MHz.


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