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Javier1
Javier1
Principal
Jan 16, 2025 12:08 PM UTC
Solved

FDCAN ROM bootloader pins for stm32H743ZI

As discussed in here, im trying to use ST\s ROM bootloader, when i read AN2606 Page 280 shows the FDCAN1 rx and tx Pins 

Javier1_0-1737029159126.png

 

 
Those pins dont exist in stm32H743ZI
@KDJEM.1 proposed "you can activate the FDCAN bootloader with only by PH13/PH14 pins." 

What does "activate" mean?, those pins dont exist

 

This topic has been closed for replies.
Andrew Neil
Andrew NeilBest answer
Super User
Jan 16, 2025 12:41 PM UTC

Looks like they've been over-general with their "STM32H74xxx".

Needs to add a note, "Where these pins are available"

@STTwo-32 @STOne-32 @KDJEM.1 

 

PS:

Also Table 1:

AndrewNeil_1-1737031749750.png

 

PPS:

Another example where this caused confusion:

https://community.st.com/t5/stm32-mcus-products/fdcan-bootloader-on-ufbga169-stm32h743ai/td-p/577760

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
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5 replies

Andrew Neil
Andrew Neil
Super User
Jan 16, 2025 12:26 PM UTC
@Javier1 wrote:

What does "activate" mean?, those pins dont exist

I guess he means those are the only pins you can use.

The stm32H743ZI datasheet says:

"The boot loader is located in non-user System memory. It is used to reprogram the flash
memory through a serial interface (USART, I2C, SPI, USB-DFU)."

So no mention of FDCAN:

AndrewNeil_0-1737030295528.png

https://www.st.com/resource/en/datasheet/stm32h743zi.pdf#page=27

 

So it looks like you can't use the bootloader via FDCAN on this chip.

 

PS:

Similarly for STM32H750VB:

https://community.st.com/t5/stm32-mcus-embedded-software/fdcan-bootloader-for-stm32h750vb/m-p/762446/highlight/true#M59030

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
    Javier1
    Javier1Author
    Principal
    Jan 16, 2025 12:36 PM UTC

     

    "The boot loader is located in non-user System memory. It is used to reprogram the flash
    memory through a serial interface (USART, I2C, SPI, USB-DFU)."

     

    I believe those are just examples, immediatly after that , the datahseet refeers to the AN2606


    So this table 119 page 280 from AN2606 is an error?

    Javier1_0-1737030886449.png

    also table 3 page 39

    Javier1_1-1737030945230.png

     

     

    hit me up in https://www.linkedin.com/in/javiermuñoz/
      Andrew Neil
      Andrew NeilBest answer
      Super User
      Jan 16, 2025 12:41 PM UTC

      Looks like they've been over-general with their "STM32H74xxx".

      Needs to add a note, "Where these pins are available"

      @STTwo-32 @STOne-32 @KDJEM.1 

       

      PS:

      Also Table 1:

      AndrewNeil_1-1737031749750.png

       

      PPS:

      Another example where this caused confusion:

      https://community.st.com/t5/stm32-mcus-products/fdcan-bootloader-on-ufbga169-stm32h743ai/td-p/577760

      A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
        KDJEM.1
        KDJEM.1
        ST Technical Moderator
        Jan 16, 2025 1:49 PM UTC

        Hello @Javier1 @Andrew Neil ,

        As mentioned in AN2606, for STM32H74, the FDCAN bootloader pins are PH13 and PH14. So, if the PH13 and PH14 pins are not available in some packages, the FDCAN bootloader is not supported. 

        KDJEM1_0-1737035198949.png

         

        The LQFP100, TFBGA100, LQFP144, and UFBGA169 STM32H743 packages do not have PH13 and PH14 pins, so the FDCAN bootloader is not supported.

        KDJEM1_1-1737035198711.png

         

        Thank you @Andrew Neil and @Javier1 for reporting your feedback about the AN2606 application note. I reported internally your suggestion internally.

        Note that, also I reported internally the datasheet typo for correction.

        KDJEM1_2-1737035273539.png

         

        Thank you for your contribution in STCommunity.

        Internal ticket number: 200567  (This is an internal tracking number and is not accessible or usable by customers). 

        Kaouthar

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