1-3 
 
Enter your choice(0-9): 
Loading by XModem through Console Port 
Introduction to XModem 
XModem protocol is a file transfer protocol that is widely used due to its simplicity and high stability. The 
XModem protocol transfers files through Console port. It supports two types of data packets (128 bytes 
and 1 KB), two check methods (checksum and CRC), and multiple attempts of error packet 
retransmission (generally the maximum number of retransmission attempts is ten). 
The XModem transmission procedure is completed by a receiving program and a sending program. The 
receiving program sends negotiation characters to negotiate a packet checking method. After the 
negotiation, the sending program starts to transmit data packets. When receiving a complete packet, 
the receiving program checks the packet using the agreed method. If the check succeeds, the receiving 
program sends acknowledgement characters and the sending program proceeds to send another 
packet. If the check fails, the receiving program sends negative acknowledgement characters and the 
sending program retransmits the packet. 
Loading Boot ROM 
Follow these steps to load the Boot ROM: 
Step 1: At the prompt "Enter your choice(0-9):" in the BOOT Menu, press <6> or <Ctrl+U>, and then 
press <Enter> to enter the Boot ROM update menu shown below: 
Bootrom update menu: 
1. Set TFTP protocol parameter 
2. Set FTP protocol parameter 
3. Set XMODEM protocol parameter 
0. Return to boot menu   
 
Enter your choice(0-3): 
Step 2: Press 3 in the above menu to download the Boot ROM using XModem. The system displays the 
following setting menu for download baudrate: 
Please select your download baudrate:  
1. 9600 
2.* 19200 
3. 38400 
4. 57600 
5. 115200 
0. Return  
 
Enter your choice (0-5): 
Step 3: Choose an appropriate baudrate for downloading. For example, if you press 5, the baudrate 
115200 bps is chosen and the system displays the following information: 
Download baudrate is 115200 bps  
Please change the terminal's baudrate to 115200 bps and select XMODEM protocol  
Press enter key when ready