
142
8048C–AVR–02/12
ATtiny43U
19.2
Fuse Bytes
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:
Notes:
Fuses. When RSTDISBL fuse has been programmed, parallel programming must be used for
unprogramming the fuse and programming the device.
2. DWEN must be unprogrammed when Lock Bit security is required. See
“Program And Data3. The SPIEN Fuse is not accessible in SPI Programming mode.
details.
Table 19-3.
Fuse Extended Byte
Fuse High Byte
Bit No
Description
Default Value
7
-
1 (unprogrammed)
6
-
1 (unprogrammed)
5
-
1 (unprogrammed)
4
-
1 (unprogrammed)
3
-
1 (unprogrammed)
2
-
1 (unprogrammed)
1
-
1 (unprogrammed)
0
Self-Programming Enable
1 (unprogrammed)
Table 19-4.
Fuse High Byte
Fuse High Byte
Bit No
Description
Default Value
RSTDISBL(1)
7
External Reset disable
1 (unprogrammed)
DWEN(2)
6
DebugWIRE Enable
1 (unprogrammed)
SPIEN(3)
5
Enable Serial Program and Data
Downloading
0 (programmed, SPI prog.
enabled)
WDTON(4)
4
Watchdog Timer always on
1 (unprogrammed)
EESAVE
3
EEPROM memory is preserved
through the Chip Erase
1 (unprogrammed,
EEPROM not preserved)
BODLEVEL2(5)
2
Brown-out Detector trigger level
1 (unprogrammed)
BODLEVEL1(5)
1
Brown-out Detector trigger level
1 (unprogrammed)
BODLEVEL0(5)
0
Brown-out Detector trigger level
1 (unprogrammed)