STM32L072RBT6 - Define PC9 as AF2 for analog output

[JZhan.33]

Hi,

I am trying to Define PC9 as AF2 for analog output.

After defining, the output keeps high. How can I define it as "TIM3_CH4" not" USB_NOE"?

It could be the reason getting HIGH.

Thanks!

Jason

[waclawek.jan]

1. What do you mean by "analog output"? PC9 has no analog function.
2. Pins marked ***/*** usually have both functionalities simply connected together, so you cannot use both peripherals at the same time when using these pins. In other words, if you have USB enabled, you are probably unable to use that pin for TIM3, and vice versa.

[EDIT]

 

JW

[waclawek.jan]

Hi @Imen DAHMEN​ ,

this is IMO a surprising feature - two peripherals controlling a single pin - and maybe even more surprising is that it is multiplexed in TIM module.

I would suggest a footnote to both the Pin definitions and Alternate functions tables, in all related datasheets.

[EDIT] It also appears, that PC9 has this "dual" function only in 'L07x, so this IMO deserves also a mention, this time in the TIM3_OR bit 4 description, in the two relevant Reference Manuals.

Can you please look at this. Thanks.

JW

[Imen.D]

Hi @Community member​ ,

Thank you for rising this up. I will take the necessary action.

Imen

[waclawek.jan]

Thanks, Imen.

Jan

@Imen DAHMEN​ 

[JZhan.33]

This is correct path. It is fixed.

Thanks!

Jason