35
XMEGA B [DATASHEET]
8291B–AVR–01/2013
Bit 3:2 – BLBAT[1:0]: Boot Lock Bit Application Table Section
These lock bits control the software security level for accessing the application table section for software access. The
BLBAT bits can only be written to a more strict locking. Resetting the BLBAT bits is possible only by executing a chip
erase command.
Table 4-11.
Boot lock bit for the application table section.
Bit 1:0 – LB[1:0]: Lock Bits
These lock bits control the security level for the flash and EEPROM during external programming. These bits are writable
only through an external programming interface. Resetting the lock bits is possible only by executing a chip erase
command. All other access; using the TIF and OCD, is blocked if any of the Lock Bits are written to 0. These bits do not
block any software access to the memory.
Table 4-12. Lock bit protection mode.
Note:
1.
Program the Fuse Bits and Boot Lock Bits before programming the Lock Bits.
BLBAT[1:0]
Group Configuration
Description
11
NOLOCK
No lock – no restrictions for SPM and (E)LPM accessing the
application table section.
10
WLOCK
Write lock – SPM is not allowed to write the application table
01
RLOCK
Read lock – (E)LPM executing from the boot loader section is not
allowed to read from the application table 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
table section, and (E)LPM executing from the boot loader section is
not allowed to read from the application table section.
If the interrupt vectors are placed in the boot loader section,
interrupts are disabled while executing from the application section.
LB[1:0]
Group Configuration
Description
11
NOLOCK3
No lock – no memory locks enabled.
10
WLOCK
Write lock – programming of the flash and EEPROM is disabled for
the programming interface. Fuse bits are locked for write from the
programming interface.
00
RWLOCK
Read and write lock – programming and read/verification of the
flash and EEPROM are disabled for the programming interface.
The lock bits and fuses are locked for read and write from the
programming interface.
Содержание XMEGA B
Страница 320: ...320 XMEGA B DATASHEET 8291B AVR 01 2013 Table 25 12 7 segments Character Table...
Страница 321: ...321 XMEGA B DATASHEET 8291B AVR 01 2013 Table 25 13 14 segments Character Table...
Страница 322: ...322 XMEGA B DATASHEET 8291B AVR 01 2013 Table 25 14 16 segments Character Table...
Страница 412: ...412 XMEGA B DATASHEET 8291B AVR 01 2013...
Страница 413: ...413 XMEGA B DATASHEET 8291B AVR 01 2013...
Страница 414: ...414 XMEGA B DATASHEET 8291B AVR 01 2013...