AT90USB128X

www.DataSheet4U.com Features USB Protocol – Based on the USB DFU class – Autobaud (8/16 MHz crystal) In-System Programming – Read/Write Flash and EEPROM on-chip memories – Read Device ID – Full chip Erase – Start application command In-Application Programming – Software Entry-points for on-chip flash drivers 1. Description The 8bits mega AVR with USB interface devices are factory configured with a USB bootloader located in the on-chip flash boot section of the controller. This USB bootloader allows to perform In-System Programming from an USB host controller without removing the part from the system or without a pre-programmed application, and without any external programming interface. This document describes the USB bootloader functionalities as well as the serial protocol to efficiently perform operations on the on chip Flash memories (Flash and EEPROM). USB DFU Bootloader Datasheet AT90USB128x AT90USB64x AT90USB162 AT90USB82 ATmega32U4 ATmega16U4 7618C–AVR–07/08 www.DataSheet4U.com 2. Bootloader Environment The bootloader is located in the boot section of the on-chip Flash memory, it manages the USB communication protocol and performs read/write operations to the on-chip memories (Flash/EEPROM). The USB bootloader is loaded in the “Bootloader Flash Section” of the on-chip Flash memory. The size of the bootloader flash section must be larger than the bootloader size.USB products are factory configured with the default on-chip USB bootloader and the required boo...