User guide

Atmel AVR2054
9
8390B-AVR-12/11
Figure 3-2. Serial bootloader programming algorithm.
3.2 Bootloader USB DFU specifics
The embedded bootloader for Atmel SAM3S microcontrollers operates in a different
way than shown in Figure 3-2 to
conform to certain features of the SAM3S
microcontroller and development boards, on which it is hosted.
Embedded bootloader for SAM3S uses Device Firmware Upgrade (DFU) standard. A
DFU component should be included in the application (see Section 3.2.2.1). The
pro
cedure of uploading a new firmware image does not change for the user. For
detailed instruction see Section 4.1.2. The
remaining part of this section describes
implementation details of SAM3S embedded bootloader and is intended for users
who will possibly modify the embedded bootloader code.