
503
42073A-MCU Wireless-02/13
ATmega2564/1284/644RFR2
Memory Lock Bits
Protection Type
BLB1 Mode
BL12
BL11
1
No restrictions for SPM or (E)LPM accessing the Boot
Loader section.
2
1
0
SPM is not allowed to write to the Boot Loader
section.
3
0
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 Interrupt Vectors are placed in the
Application section, interrupts are disabled while
executing from the Boot Loader section.
4
0
1
(E)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.
Notes:
1. Program the Fuse bits and Boot Lock bits before programming the LB1 and LB2.
2. “1” means un-programmed, “0” means programmed.
31.2 Fuse Bits
on page 504 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.
Table 31-3. Extended Fuse Byte
Ext. Fuse Byte
Bit No
Description
Default Value
7
1
6
1
5
1
4
1
Reserved
3
Do not modify
1 (un-programmed)
BODLEVEL2
(1)
2
Brown-out Detector trigger level
1 (un-programmed)
BODLEVEL1
(1)
1
Brown-out Detector trigger level
1 (un-programmed)
BODLEVEL0
(1)
0
Brown-out Detector trigger level
0 (programmed)
Notes:
Table 31-4. Fuse High Byte
Fuse High Byte
Bit No
Description
Default Value
OCDEN
(4)
7
Enable On-chip debugging
(OCD)
1 (un-programmed, OCD
disabled)
JTAGEN
6
Enable JTAG interface
0 (programmed, JTAG
enabled)
SPIEN
(1)
5
Enable Serial Program and Data
Downloading (SPI)
0 (programmed, SPI
programming enabled)
WDTON
(3)
4
Watchdog Timer always on
1 (un-programmed)