2023-10-13 04:27 PM
I'm looking at the STM32H7B0xB. I'm confused about what the actual maximum baud rate of the UART (in asynchronous mode) is. I'm getting three conflicting answers:
Does anyone know what the maximum UART speed in asynchronous mode is for these devices?
2023-10-14 06:46 AM - edited 2023-10-14 06:54 AM
General rule of thumb is the APB clock for the bus the U(S)ART is on DIV8, the H7B0 APB1/APB2 max speed is 140 MHz, so 17.5 Mbaud, but the rates will need to divide relatively cleanly so the rate error can get high (actual vs desired). And Asynchronous Serial isn't known for its robustness.
You can route in a usart_ker_ck through the kernel clock distribution tree. Need to find a table of maximum clocks there. Ok, so per RM fuart_ker_ck / fusart_ker_ck is 280 MHz, so 35 Mbaud