Project name：serial communication.
Specific requirements：realize serial port loopback test, send data from PC serial debug assistant, and send back to PC after the development board receives it.
1.download the bit file to the development board and then switch the downloader to the USER_JTAG interface. (The downloader has integrated USB to serial function) As shown in the figure.
2.Open the device manager to view the COM number of the serial port as shown in the following figure.
3.Open the serial debugging tool to set the serial port, COM port set to the value viewed in the device manager, baud rate set to 9600, data bits set to 8, parity bit set to None, stop bit set to 1, and then click Open serial port, as shown in the figure below.
4.Click Manual input to send, enter the content to be sent in the HEX format input or character format input box, click Send to see the sent content and the returned content in the display area, as shown in the following figure.