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waclawek.jan
waclawek.jan
Super User
October 11, 2023
Question

STM32F407 - HSE is not divided by 128 when used as RTC clock

  • October 11, 2023
  • 2 replies
  • 2415 views

waclawekjan_0-1697041208230.png

This is not true, according to RM, HSE is divided by RCC_CFGR.RTCPRE which ranges from HSE/2 to HSE/31.

JW

 

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    2 replies

    S
    Sarra.S
    ST Employee
    October 11, 2023

    Hello @waclawek.jan, 

    Thank you for bringing up this issue

    I can already confirm that the information in the datasheet is not totally coherent with the RTC block diagram (HSE/32): 

    SarraS_0-1697042947004.png

    I will further look into this issue and get back to you asap 

    Thank you! 

    To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.
    waclawek.jan
    waclawek.janAuthor
    Super User
    October 12, 2023

    Hi @Sarra.S ,

    Indeed, a third divider, wrong again.

    I understand that it's consequence of copy/paste, but it deserves to be cleaned up.

    Thanks,

    Jan

    S
    Sarra.S
    ST Employee
    October 12, 2023

    Hello again @waclawek.jan, 

    I can confirm that The correct description is in RCC so from HSE/2 to HSE/31.

    This issue is tracked internally to be corrected (Ticket 163728). 

    Thank you for bringing up this issue.

    To give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.
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