Unable to Achieve 12.5 Mbit/s Baud Rate on USART/UART (NUCLEO-N657X0-Q - STM32N6x7xx)

[AdelF]

I am working with the NUCLEO-N657X0-Q board featuring an STM32N6x7xx microcontroller. The reference manual for this series specifies that the USART/UART peripherals can support speeds "up to 12.5 Mbit/s".

I am attempting to configure the peripheral to this maximum speed but have been unsuccessful, running into standard clock-division limitations.

When I attempt to configure a rate this high in STM32CubeMX , the resulting clock divider is simply disallowed. The maximum reliable baud rate I have been able to set on the device is 6.25 Mbit/s.

Any guidance on the exact register settings or clock tree configuration required to hit the 12.5 Mbit/s mark would be greatly appreciated.

Thank you in advance for your help.

[TDK]

Probably you need to change oversampling from 16 (default) to 8. You can't achieve the max speed with 16x oversampling. Works for me here. Include your IOC if you're still having trouble.