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Associate II
April 2, 2026
Solved

SDIO and I2S MCLK output warning

  • April 2, 2026
  • 2 replies
  • 124 views

I'm using a STM32F407VG (actually a disc-1 board). I've set I2S2 in full-duplex master mode and generating the MCLK out on PC6 for an external slave codec. So far so good.

Now i want to set SDIO interface in full-duplex 4-bits mode but CubeMX throws a warning about a partial conflict with I2S master clock out. 

Frankly i have no clue about it, can i safely ignore the warning?

 

Best answer by AScha.3

>can i safely ignore the warning?

As long as its a yellow warning - yes.

It just shows that you cannot use a pin for this or that, because pin is already in use.

If a conflict in use would exist, its red and blocks the setting, maybe to avoid to use a pin for two different functions.

Or to set a not allowed clock speed. 

If you hover on it  , you should get an info , whats the problem.

2 replies

AScha.3
AScha.3Best answer
Super User
April 2, 2026

>can i safely ignore the warning?

As long as its a yellow warning - yes.

It just shows that you cannot use a pin for this or that, because pin is already in use.

If a conflict in use would exist, its red and blocks the setting, maybe to avoid to use a pin for two different functions.

Or to set a not allowed clock speed. 

If you hover on it  , you should get an info , whats the problem.

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omaroskiAuthor
Associate II
April 3, 2026

Yes, it's a yellow warning, hovering on it i only get a general partial conflict with MCLKO. PC6 has indeed an alternate function for one of the SDIO data pins for the 8-bits mode, which is red in the dropdown list. So i understand i can't use 8-bits mode since MCLKO and SDIO data pin share the same pin.