cancel
Showing results for 
Search instead for 
Did you mean: 

UART cannot set high baud rate

fkst
Associate II

I have a uart peripheral whose baud rate can only be set to 3.125M. However, the baud rate of another uart peripheral with the same clock configuration in the project can be set to 12.5M. I want to know what the baud rate limit is based on? How to increase the baud rate from 3.125M to 12.5M?

 

fkst_0-1703066288603.png

fkst_2-1703066511624.png

 

fkst_1-1703066310126.png

 

12 REPLIES 12
TDK
Guru

CubeMX is using the UART5 clock selection to determine the acceptable UART7 speeds. Clearly a bug. In MCUA it's set to SYSCLK=200MHz but in MCUB it's set to PCLK1=50MHz, hence the difference in behavior.

Easy workaround: enable UART5, set the clock selection to SYSCLK to match that of UART7, then disable UART5.

TDK_0-1703134308790.png

If you feel a post has answered your question, please click "Accept as Solution".
Amel NASRI
ST Employee

Hello @fkst & @TDK ,

Even though the solution is already found, I let our STM32CubeMX expert @Semer CHERNI investigate the issue deeply.

Question will be moved to STM32CubeMX forum board.

-Amel

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.

Semer CHERNI
ST Employee

Hello @fkst 

I confirm the issue related to STM32CubeMX. It's now tracked internally for analysis and future fix (169726: this is an internal ticket number)

KR,
Semer.

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.