Refer to https://www.st.com/resource/en/datasheet/stm32f446re.pdf
In section 3.23 on PDF page 32, it says:
"The devices embed four universal synchronous/asynchronous receiver transmitters (USART1, USART2, USART3 and USART6) and four universal asynchronous receiver transmitters (UART4, and UART5)."
It should say two UARTs (which would then agree with everything else!)
On the following page it says:
"The USART1 and USART6 interfaces are able to communicate at speeds of up to 11.25 Mbit/s. The other available interfaces communicate at up to 5.62 bit/s."
Based on table 8 "USART feature comparison" that is just below that it should be 5.62 Mbit/s"
Please bring this to the attention of the group at ST that creates the datasheets.
