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danielya
danielya
Associate
May 27, 2008
Question

RCC_WaitForHSEStartUp function

  • May 27, 2008
  • 2 replies
  • 720 views
Posted on May 27, 2008 at 21:37

RCC_WaitForHSEStartUp function

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    2 replies

    lanchon
    lanchon
    Associate III
    May 17, 2011
    Posted on May 17, 2011 at 12:35

    I recommend you consider the fwlib as an example or an implementation guide rather than something to build upon, as it has a number of problems. I wish ST would release include files for the hardware...

    danielya
    danielyaAuthor
    Associate
    May 17, 2011
    Posted on May 17, 2011 at 12:35

    In the STM32 datasheet is written:

    ''tSU(HSE) is the startup time measured from the moment it is enabled (by software) to a stabilized 8 MHz oscillation is reached. This value is measured for a standard crystal resonator and it can vary significantly

    with the crystal manufacturer''.

    The same time the timeout value for the RCC_WaitForHSEStartUp function of the Firmware Library is hard defined in stm32f10x_rcc.c module equal to 128. In my case I tried 128, 144 and only with 192 the function starts to return SUCESS. If this value is so resonator dependend, why the library designers did not made it a function parameter?

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