Hi Fang Li. Its a customer board. I configure the UART with 19200, 8 bits, None parity and 1 bit to stop. The problem is when i change the baud rate in software, i need to verify this change e modify my baud rate in MCU. The problem is i dont find where in the software i see the change of data. I'm using the example usb cdc of the site MCU on eclipse.