Datasheet
297
8021G–AVR–03/11
ATmega329P/3290P
Notes: 1. Program the Fuse bits and Boot Lock bits before programming the LB1 and LB2.
2. “1” means unprogrammed, “0” means programmed
27.2 Fuse Bits
The ATmega329P/3290P has three Fuse bytes. Table 27-3 - Table 27-5 describe briefly the
functionality of all the fuses and how they are mapped into the Fuse bytes. Note that the fuses
are read as logical zero, “0”, if they are programmed.
Notes: 1. See Table 28-9 on page 337 for BODLEVEL Fuse decoding.
2. Port G, PG5 is input only. Pull-up is always on. See ”Alternate Functions of Port G” on page 82
BLB1 Mode BLB12 BLB11
111
No restrictions for SPM or LPM accessing the Boot Loader
section.
2 1 0 SPM is not allowed to write to the Boot Loader section.
300
SPM is not allowed to write to the Boot Loader section, and LPM
executing from the Application section is not allowed to read
from the Boot Loader section. If Interrupt Vectors are placed in
the Application section, interrupts are disabled while executing
from the Boot Loader section.
401
LPM executing from the Application section is not allowed to
read from the Boot Loader section. If Interrupt Vectors are
placed in the Application section, interrupts are disabled while
executing from the Boot Loader section.
Table 27-2. Lock Bit Protection Modes
(1)(2)
(Continued)
Memory Lock Bits Protection Type
Table 27-3. Extended Fuse Byte
Extended Fuse Byte Bit No Description Default Value
–7– 1
–6– 1
–5– 1
–4– 1
–5– 1
BODLEVEL1
(1)
2 Brown-out Detector trigger level 1 (unprogrammed)
BODLEVEL0
(1)
1 Brown-out Detector trigger level 1 (unprogrammed)
RSTDISBL
(2)
0 External Reset Disable 1 (unprogrammed)