Editing AVR microcontrollers (section)

=== Bootloader ===
Most AVR models can reserve a [[bootloader]] region, 256&nbsp;bytes to 4&nbsp;KB, where re-programming code can reside. At reset, the bootloader runs first and does some user-programmed determination whether to re-program or to jump to the main application. The code can re-program through any interface available, or it could read an encrypted binary through an Ethernet adapter like [[Preboot Execution Environment|PXE]]. Atmel has application notes and code pertaining to many bus interfaces.<ref>{{cite web|url=http://www.atmel.com/dyn/resources/prod_documents/doc2541.pdf |archive-url=https://web.archive.org/web/20050516025202/http://www.atmel.com/dyn/resources/prod_documents/doc2541.pdf |archive-date=2005-05-16 |url-status=live|title=DES-encrypted AVR Bootloader|access-date=2012-09-19}}</ref><ref>{{cite web|url=http://www.atmel.com/dyn/resources/prod_documents/doc2589.pdf|title=AES-encrypted AVR Bootloader|access-date=2012-09-19}}</ref><ref>{{cite web|url=http://www.atmel.com/dyn/resources/prod_documents/doc2589.pdf|title=XMEGA Bootloader|access-date=2012-09-19}}</ref><ref>{{cite web|url=http://www.atmel.com/dyn/resources/prod_documents/doc7618.pdf |archive-url=https://web.archive.org/web/20060628210714/http://www.atmel.com/dyn/resources/prod_documents/doc7618.pdf |archive-date=2006-06-28 |url-status=live|title=AVR USB Bootloader|access-date=2012-09-19}}</ref>