USB Library
Device - CDC - Serial Emulator

This demo shows how to use the CDC class to create a USB to UART bridge device. This demo is very similar to the Device - CDC Basic Demo, with the following differences: 

  1. The CDC serial emulator firmware enables the hardware UART of the microcontroller and forwards any received UART RX bytes to the host terminal program through the virtual COMx port. Similarly, any bytes received from the host terminal program over the COMx port get forwarded out the hardware UART TX microconroller pin. This provides a bi-directional USB to UART bridge functionality.
  2. The CDC serial emulator firmware uses SET_LINE_CODING information to update the hardware UART baud rate setting. The host automatically sends one or more SET_LINE_CODING requests upon the user opening the COMx port or changing the COMx port baud rate (or other data encoding settings) from the terminal program. This allows the host software to control the hardware UART's baud rate value.
 

The CDC serial emulator demo uses the same USB drivers that are needed for the CDC Basic Demo. Upon plugging in a USB CDC serial emulator device, and installing any necessary drivers (for Windows, for Mac/Linux OSes, the drivers are normally automatically installed and come with the OS), the device will produce a COMx port (on Windows, on Mac a /dev/tty.usbmodemXXXX object, and on a Linux machine a /dev/ttyACMx object) that PC applications such as serial terminal programs can connect to. 

 

See the Device - CDC Basic Demo information for more details.

MLA - USB Library Help Version : 2.16
http://www.microchip.com/mla