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Graduate
April 8, 2024
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STM32G050C8T6 ADC_IN11: inconsistency in the datasheet?

  • April 8, 2024
  • 7 replies
  • 4539 views

Hello,

According to the datasheet PB7 can be used as  ADC_IN11.

Is this an error in datasheet? ADC_IN11 is already used by PB10 and cubeMX doesn't seem to allow me to use PB7 or to remap this pin. How can I use ADC_IN11 on pin PB7 as mentioned in datasheet?

Thanks

AHame_0-1712593418190.png

 

    This topic has been closed for replies.
    Best answer by Bubbles

    Hi @AHame,

    the DS is unclear as it indicates two possible bondings of the ADC inputs without making the distinction between packages. A decision was made to make the ADC inputs available on smaller packages even if the primary pin dedicated for the function is not available.

    So LQFP48 has for example ADC_IN11 bonded to PB10, but as PB10 is not on small packages, the ADC_IN11 is rerouted to PB7 on those. But on LQFP48, ADC_In11 is only on PB10.

    I explained the situation to the datasheet responsible and it should be fixed soon.

    BR,

    J

    7 replies

    Graduate II
    April 8, 2024

    Interesting catch..

    Also I don't see ADC_IN14 go anywhere, and ADC_IN15 routes to PA11/PB11/PA9 and ADC_IN16 PA12/PB12/PA10, but some of those may be bond-out related

    https://www.st.com/resource/en/datasheet/stm32g050c8.pdf

    @mƎALLEm 

    Technical Moderator
    April 9, 2024

    Also I don't see ADC_IN14 go anywhere


    Just for your information: ADC_IN12, ADC_IN13 and ADC_IN14 are tied internally to internal sources:

    RM0454 rev 5 / Figure 32.:

    SofLit_0-1712670607757.png

    I also have a doubt regarding ADC_IN16: mapped on PB12 and PA12!

    Need to check..

    Graduate II
    April 9, 2024

    Yes, didn't get to the RM when I posted. Don't see any reference in the DS.

    Perhaps some "note" related to VBAT pin would be appropriate? The DS is frequently used by HW designers to get the lay-of-the-land without getting dragged into the specifics at a SW / register level.

    Technical Moderator
    April 8, 2024

    Hello all,

    Need to check internally and get back to you as soon as I have a feedback.

    ST Employee
    April 9, 2024

    Generally speaking the DS is usually more accurate than tools like CubeMX

    BR,

    J

    Graduate II
    April 9, 2024

    Would definitely agree there, but it's always good to check for internal consistency with CubeMX, .SVD files, include files and docs.

    AHameAuthor
    Graduate
    April 9, 2024

    Sure, I agree that the source of truth should be the datasheet not cube, but I usually use both the datasheet and Cube just to sanity check during the hardware design.

    That being said my question was regarding ADC_IN11 and it is still not clear to me how I'm supposed to use PB7 configured as an ADC input ( ADC_IN11).

    Should I assume that PB10 and PB7  are internally connected on the die? That would mean that if I configure the ADC channel 11 using the ADC registers  I could then use both PB7 or PB10 for the input pin? Seems strange to me but that could technically be possible. 

     

    Thanks

    AHameAuthor
    Graduate
    April 15, 2024

    @mƎALLEm Any updates on that case ? I'll do some testing on my end but I'd like an official answer.

    If the datasheet is indeed wrong I would need to spin a new board so please let me know as soon as possible.

    Thanks

    Technical Moderator
    April 16, 2024

    @AHame 

    I didn't get a feedback yet. I will keep you informed as soon as I have one. So please be patient :).

    AHameAuthor
    Graduate
    April 22, 2024

    I read you message again I understand what you mean now. This datasheet is clearly misleading and should indeed be fixed...

    Technical Moderator
    April 23, 2024

    Internal ticket number 178606 (not accessible by community users).