5-3
Enter your choice(0-9):
Loading Software Using XModem Through Console Port
Introduction to XModem
XModem is a file transfer protocol that is widely used due to its simplicity and good performance.
XModem transfers files via console port. It supports two types of data packets (128 bytes and 1 KB), two
check methods (checksum and CRC), and error packet retransmission mechanism (generally the
maximum number of retransmission attempts is ten).
The XModem transmission procedure is completed by the cooperation of a receiving program and a
sending program: The receiving program sends a negotiation packet to negotiate a packet check
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 an acknowledgement packet and the sending program
proceeds to send another packet; otherwise, the receiving program sends a negative
acknowledgement packet and the sending program retransmits the packet.
Loading Boot ROM software
Follow these steps to load the Boot ROM software:
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: Enter
3
in the above menu to load the Boot ROM software using XModem. The system displays
the following download bits per second setting menu:
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 download bits per second. For example, if you select
5
, the 115200 bps
rate 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
Now, press <
Enter
>.