Multitech MultiConnect xDot MTXDOT Series, Руководство разработчика

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GETTING STARTED
12 MultiConnect
®
xDot
TM
MTXDOT Developer Guide
AT Command Port: XR21V1410 USB UART
You may need to install a driver for the debug port to function properly. Go to:
https://developer.mbed.org/handbook/Windows-serial-configuration
Mac
On Mac systems, COM ports appear in the Device Manager as:
/dev/cu.usbmodemx
Where x is a string of numbers and possibly letters, ending in a number.
The COM port with lower number is the AT command port and COM port with the higher number is the debug
port.
Updating Firmware Using the xDot Bootloader
The xDot bootloader allows firmware upgrades either via YMODEM through command or debug serial ports at
115,200 bps.
To enter the bootloader, enter the characters xdt on either serial port upon processor reset. The bootloader allows
250ms for x and then 500 ms each for d and t. If these timers expire before receiving the proper character or
another character is received, the bootloader jumps to the application code.
The bootloader includes an option to upgrade application code via YMODEM or jump to the application
code. During the YMODEM file transfer, the new application is programmed directly into the STM32L151CC
flash memory.
Since the new application is directly programmed into the STM32L151CC flash memory and the xDot has no
on board memory to back up the old application, recovery from failed download is the responsibility of the
host system.
The mbed build process creates two files when building for the bootloader. The
name_of_program_application.bin file is the application with the correct offset that can be transferred via
YMODEM onto the xDot using the bootloader. The name_of_program.bin file is the entire program with the
bootloader than can be flashed on using jtag (this file cannot be transferred onto the xdot via YMODEM).
To build xDot firmware with the bootloader, you must include the bootloader.bin file in the mbed-os directory
along with an mbed_app.json file that includes directives describing the space used for the bootloader and the
location where the bootloader.bin file resides.
Note: For an application to run at the correct offset, it needs location where it will reside so the vector
table is correct.
mbed-os version 5.5.4, includes hooks that allow you to easily add a boot loader for the xDot. Go to
https://docs.mbed.com/docs/mbed-os-handbook/en/latest/advanced/bootloader/ for details.
For the bootloader, create a file with the following content. (Actual size may vary, but needs to
accommodate the bootloader size.) Name the file mbed_app.json and place it in the root directory.
{
"target_overrides": {
"XDOT_L151CC": {
"target.restrict_size": "0x8000"
}
}