The USB Secure DFU Bootloader example uses the Bootloader modules to implement a bootloader with secure Device Firmware Update (DFU) functionality. It uses CDC ACM USB class, commonly known as Virtual COM port. After connecting the USB cable, the development kit will enumerate as a COMx port on Windows hosts or as a /dev/ttyACMx device on Linux/Unix hosts. The port can be opened and closed just like a traditional serial port.
For Windows XP/7 hosts, you must manually install the driver that is located in the example directory:
Windows 8 (and later) hosts will pick the correct driver (usbser.sys) automatically.
After the Virtual COM port is installed and detected by the host computer, the device can be tested as in Serial Secure DFU Bootloader.