3.1 Overview

The USB device stack is divided into three parts:

USB Device Controller (UDC) Provides USB Chapter 9 Compliance
USB Device Interface (UDI) Provides USB Class Compliance
USB Device Driver (UDD) Provides the USB Interface for Each AVR Product

Figure 3-1. USB Device Stack Architecture

The online versions of the documents are provided as a courtesy. Verify all content and data in the device’s PDF documentation found on the device product page.