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31
8210C–AVR–09/11
Atmel AVR XMEGA D
• Bit 5:4 – BLBA[1:0]: Boot Lock Bit Application Section
These lock bits control the security level for the application section. The BLBA bits can only be
written to a more strict locking. Resetting the BLBA bits is possible by executing a chip erase
command.
Table 4-8.
Boot lock bit for the boot loader section.
BLBB[1:0]
Group Configuration
Description
11
NOLOCK
No lock – no restrictions for SPM and (E)LPM accessing
the boot loader section.
10
WLOCK
Write lock – SPM is not allowed to write the boot loader
section.
01
RLOCK
Read lock – (E)LPM executing from the application
section is not allowed to read from the boot loader
section.
If the interrupt vectors are placed in the application
section, interrupts are disabled while executing from the
boot loader section.
00
RWLOCK
Read and write lock – SPM is not allowed to write to the
boot loader section, and (E)LPM executing from the
application section is not allowed to read from the boot
loader section.
If the interrupt vectors are placed in the application
section, interrupts are disabled while executing from the
boot loader section.
Table 4-9.
Boot lock bit for the application section.
BLBA[1:0]
Group Configuration
Description
11
NOLOCK
No Lock - no restrictions for SPM and (E)LPM
accessing the application section.
10
WLOCK
Write lock – SPM is not allowed to write the application
section.
01
RLOCK
Read lock – (E)LPM executing from the boot loader
section is not allowed to read from the application
section.
If the interrupt vectors are placed in the boot loader
section, interrupts are disabled while executing from the
application section.
00
RWLOCK
Read and write lock – SPM is not allowed to write to the
application section, and (E)LPM executing from the boot
loader section is not allowed to read from the
application section.
If the interrupt vectors are placed in the boot loader
section, interrupts are disabled while executing from the
application section.