Topic : Crytal Freq used in STM32F107 daughter card.

Forum : ARM

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February 1, 2011 - 5:35am
Guest

Hello
In your QuickStart_STM32F107 example
That is Raisonance\Ride\Examples\ARM\REva\QuickStart_STM32F107\main.c file
Line number 143,144 its mentioned

/* PLLCLK = 8MHz * 7 = 56 MHz */
RCC_PLLConfig(RCC_PLLSource_PREDIV1, RCC_PLLMul_7);

But when I was seeing the schematic of duaghter board the crystal frequency is 25M.
And not 8MHz . Please clarify.

Toolchain : Ride 7
Board : Revav3.3
Processor : STM32F107

Also in case the crystal freq is 25M then in Ride7 should I change
RLink Configuration-->Advanced Options --> Crystal Freq to be 25M instead of 8M.

Thanks In Advance
Lokesh Siddhu
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February 7, 2011 - 3:59pm
Raisonance Support Team

Hi Lokesh,

You are right, there are some problems with this example.
I wrote this looong ago, when the ST libraries were not polished and quite difficult to use. We will correct the example so that the correct information is used.
The main problem here is that the comment is wrong.

2 things:
- In your ST Library projects, always define the STM32F10X_CL, USE_STDPERIPH_DRIVER and HSE_Value macros. This way you will have better chances that your project works.
- If you need an authoritative example that shows how to use the ST Library in your projects, please refer to the system_stm32f10x.c file form the ST Library. The comments are very useful and will be much safer than our examples.

Best Regards,