USB Libraries Help > USB Device Libraries > USB CDC Device Library > Using the Library > Library Overview
MPLAB Harmony USB Stack
Library Overview

The USB CDC Device Library mainly interacts with the system, its clients and function drivers, as shown in the Abstraction Model. 

The library interface routines are divided into sub-sections, which address one of the blocks or the overall operation of the USB CDC Device Library.

Library Interface Section 
Description 
Functions 
Provides event handler, read/write, and serial state notification functions.