
103
2535J–AVR–08/10
ATtiny13
17.2 Fuse Bytes
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.
When programming the RSTDISBL fuse, High-voltage Serial programming has to be used to
change fuses to perform further programming.
Notes: 1. The SPIEN fuse is not accessible in SPI Programming mode.
4. The default value of SUT1..0 results in maximum start-up time for the default clock source.
5. The default setting of CKSEL1..0 results in internal RC Oscillator @ 9.6 MHz. See
Table 18-3Table 17-3.
Fuse High Byte
Fuse Bit
Bit No
Description
Default Value
–
7
–
1 (unprogrammed)
–
6
–
1 (unprogrammed)
–
5
–
1 (unprogrammed)
4
Self Programming Enable
1 (unprogrammed)
3
debugWire Enable
1 (unprogrammed)
2
Brown-out Detector trigger level
1 (unprogrammed)
1
Brown-out Detector trigger level
1 (unprogrammed)
0
External Reset disable
1 (unprogrammed)
Table 17-4.
Fuse Low Byte
Fuse Bit
Bit No
Description
Default Value
7
Enable Serial Programming and Data
Downloading
0 (programmed)
(SPI prog. enabled)
EESAVE
6
Preserve EEPROM memory through
Chip Erase
1 (unprogrammed)
(memory not preserved)
5
Watchdog Timer always on
1 (unprogrammed)
4
Divide clock by 8
0 (programmed)
3
Select start-up time
1 (unprogrammed)
2
Select start-up time
0 (programmed)
1
Select Clock source
1 (unprogrammed)
0
Select Clock source
0 (programmed)