False Warning Clock Configuration on STM32CubeMX

[jeck_asteroid]

Posted on July 18, 2016 at 22:39

In STM32CubeMX v4.15.1 arise false warning Clock Configuration for board NUCLEO STM32F411RE

(APB1 peripherial clocks). See screenshot and .ioc file in atachment. #bug #stm32cube

[slimen]

Posted on July 19, 2016 at 12:08

Hi,

Following the

http://www.st.com/content/ccc/resource/technical/document/datasheet/b3/a5/46/3b/b4/e5/4c/85/DM00115249.pdf/files/DM00115249.pdf/jcr:content/translations/en.DM00115249.pdf

: the maximum allowed frequency of the APB1 is 50 MHz.I don't have this warning, when I create new project with NUCLEO STM32F411RE.But when I checked your .ioc, the error persist ! Maybe this is due to update an old .ioc.So, try with creation of new project, I think this will resolve your problem.Please let me know if this workaround resolves your issue or you still have this issue.Regards

[jeck_asteroid]

Posted on July 19, 2016 at 21:33

Hi, forumstm32

This warning no problem for me. I ignore it. But I hope developers fixed this.I create new project with NUCLEO STM32F411RE without warning too.I dont know why arise this warning after editing my project file.

[Sirma Siang]

Posted on November 02, 2016 at 15:51

Hello Asteroid Jeck,

I want to thank you for your bug report.

This definetely help us to improve our product.

After a deep check into datasheet and reference manual, you are right, the maximum APB bus speed is 50MHz. But when the I2C IP is enabled, this speed is limited to 42MHz. You can refer to page 486 of the reference manual.

It says:

''

The FREQ bits must be configured with the APB clock frequency value (I2C peripheral

connected to APB). The FREQ field is used by the peripheral to generate data setup and

hold times compliant with the I2C specifications. The minimum allowed frequency is 2 MHz,

the maximum frequency is limited by the maximum APB frequency (42 MHz) and an intrinsic

limitation of 46 MHz.

''

CubeMx message, and error, is taking this into account.

If you disable the I2C (just for test), you will see that this error will gone.

Hope it clarify cubeMX behave.

Kind Regards

Sirma