Datasheet

311
8284D–AVR–6/11
ATmega169A/PA/329A/PA/3290A/PA/649A/P/6490A/P
Notes: 1. Program the Fuse bits and Boot Lock bits before programming the LB1 and LB2.
2. “1” means unprogrammed, “0” means programmed
28.2 Fuse Bits
The ATmega169A/169PA/329A/329PA/3290A/3290PA/649A/649P/6490A/6490P has three
Fuse bytes. Table 28-3 toTable 28-5 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 29-17 on page 354 for BODLEVEL Fuse decoding.
2. Port G, PG5 is input only. Pull-up is always on. See ”Alternate Functions of Port G” on page 85
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 28-2. Lock Bit Protection Modes
(1)(2)
(Continued)
Memory Lock Bits Protection Type
Table 28-3. Extended Fuse Byte
Extended Fuse Byte Bit No Description Default Value
–7– 1
–6– 1
–5– 1
–4– 1
BODLEVEL2
(1)
2 Brown-out Detector trigger level 1 (unprogrammed)
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)