I had created the project for STM32F4Discovery from STM32CubeMX, and set the system to use external crystal of 8 MHz. I configured USART1 and USART2 to function as UART and repeatedly send strings out. The output looks all fine expect when configure the UART baudrate to 921600. When configure UART baudrate to 921600 on STM32F4Discovery, all received are 0x00 .
I had tried the similar configuration on STM32F0Discovery, on which using HSI system clock. By my understanding, this will be less accurate than the HSE used on STM32F4Discovery board. But the UART1 and UART2 running on baudrate of 921600 is all fine.
I’m not so sure if I had made mistake on clock configuration. Please help.