Atmel AT32UC3C0128C, Manual

Page: 6 / 37

6
32166A–AVR32806–06/11
Atmel AVR32806
6.2.1 General purpose fuse bits
Atmel AVR UC3
series devices have 32 general purpose fuse bits. When these bits are erased,
they are set to logical 1.
AVR UC3 devices are shipped with their fuses set as follows:
•
For Atmel AVR UC3 C series: The general purpose fuses are set to F877FFFFh
•
That is, BOD is enabled, and the boot loader area is set to 8192 bytes.
The general purpose fuse bits can be changed in one of the following ways:
•
With a hardware debugger, use the
avr32program writefuses
command (see
avr32program
help writefuses
), or execute “Program Fuses...” on the chosen hardware debugger Atmel
AVR32 target in
Atmel AVR32 Studio
• With ISP, use the
CONFIGURATION
memory with BatchISP (see
Section 7.4.2
), or execute
“Program Fuses...” on the appropriate ISP AVR 32-bit target in
AVR32 Studio
(see
Section
7.5.2
)
• From the running embedded application, use the WGPB, EGPB, PGPFB, and EAGPF
FLASHC commands. See the AVR UC3 datasheets for further information, and be careful of
the lock errors that can occur with these commands
6.2.2 Flash user page
6.2.2.1 Description
The boot loader uses two words in the flash user page to store its configuration:
•
Configuration Word1 at address 808001FCh is read first at boot time to know if the ISP
process should start unconditionally, and whether it should use Configuration Word2, where
further configuration is stored (see
Table 6-1.
)
• Configuration Word2 at address 808001F8h stores the I/O conditions that determine
whether the USB DFU ISP or the application is started at the end of the boot process (see
Table 6-2.
)