Atmel ATSAM3S-EK2 データシート
44
Atmel AVR2055
8348D-AVR-06/12
9.3.1 Setting fuse bits
devices during production. It also describes some use cases when certain fuse bits
require values different from the default ones. Based on application-specific
descriptions.
NOTE
Modifying fuse bit settings is possible only using JTAG programming interfaces, and
cannot be done with the Serial Bootloader package tools.
Table 9-4. Fuse bit settings for the ATxmega256A3/D3 device.
Table 9-4. Fuse bit settings for the ATxmega256A3/D3 device.
Option
Default value in
ATxmega256A3/D3
devices
Comments
JTAGUSERID 0xFF
Can be changed according to application-specific
requirements
WDWP
8 cycles
(8ms @ 3.3V)
Can be changed during application development.
Must be disabled for final products
WDP
8 cycles
(8ms @ 3.3V)
Must be always enabled
DVSDON
OFF
Must be always enabled
BOOTRST
Application Reset
Must be set to BOOTLDR if the device needs to
be programmed with Serial Bootloader or if OTAU
support is required
BODACT
BOD Disabled
Can be changed according to application-specific
requirements
BODPD
BOD Disabled
SUT
0ms
WDLOCK
OFF
JTAGEN
ON
EESAVE
OFF
Can be changed according to application-specific
requirements, but external clock source shall not
be used by sleeping devices
BODLVL
1.6V
Resulting
bytes:
FUSEBYTE0
0xFF
FUSEBYTE1
0x00
FUSEBYTE2
0xFF
FUSEBYTE4
0xFE
FUSEBYTE5
0xFF
By default, programming with Serial Bootloader is not allowed, and so firmware can
be uploaded only over the JTAG interface. To turn on bootloader support, first, the
BOOTRST fuse must be set to BOOTLDR, which results in the following fuse bytes:
0xFF, 0x00, 0xBF, 0xFE, 0xFF
Second, a firmware image of the embedded the embedded bootloader (without OTAU
support) shall be programmed to the Atmel ATxmega256A3/Atmel ATxmega256D3