Fuse Bits
The ATmega48/88/168 has three Fuse bytes. Table 118 - Table 121 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 118. Extended Fuse Byte for mega48
Extended Fuse Byte
Bit No
Description
Default Value
–
7
6
5
4
3
2
1
0
–
1
–
–
1
–
–
1
–
–
1
–
–
1
–
–
1
–
–
1
SELFPRGEN
Self Programming Enable
1 (unprogrammed)
Table 119. Extended Fuse Byte for mega88/168
Extended Fuse Byte
Bit No
Description
Default Value
–
–
–
–
–
7
6
5
4
3
–
–
–
–
–
1
1
1
1
1
Select Boot Size
(see Table 113 for details)
BOOTSZ1
2
0 (programmed)(1)
Select Boot Size
(see Table 113 for details)
BOOTSZ0
BOOTRST
1
0
0 (programmed)(1)
1 (unprogrammed)
Select Reset Vector
Note:
1. The default value of BOOTSZ1..0 results in maximum Boot Size. See Table 124 on
page 275 for details.
272
ATmega48/88/168
2545D–AVR–07/04
ATMEL [ ATMEL ]
