AVR fuse bits settings

Posted by Omkar on April 3, 2010

Setting AVR fuse bits correctly is most important and equally confusing part for many beginners. In this post I have presented some of the ready to use fuse bit settings and corresponding batch files, which can be used with AVRdude.

Link for downloading avrdude batch files (to be used with USBasp) is given at the end of this post.

Factory Default Settings for ATmega16/32.

H fuse:
JTAG            : Enabled
OCD             : Disabled
SPI Programming : Enabled
CKOPT           : Unprogrammed
EEPROM Preserve : Unprogrammed (EEPROM not preserved)
BOOT size       : 1024 words
Reset Vector    : User flash code

L fuse:
Brown-out level : 2.7V
Brown-out detect: Disabled
Startup timing  : Default
Clock Source    : Internal, 1MHz

External Crystal upto 16MHz, JTAG disabled. Rest of the options : Default.Internal 8MHz oscillator, JTAG disabled. Rest of the options : Default.
Factory Default Settings for ATmega8.

H fuse:
Reset Disabled  : Unprogrammed (Reset pin is enabled)
Watchdog        : Off
SPI Programming : Enabled
CKOPT           : Unprogrammed
EEPROM Preserve : Unprogrammed (EEPROM not preserved)
BOOT size       : 1024 words
Reset Vector    : User flash code

L fuse:
Brown-out level : 2.7V
Brown-out detect: Disabled
Startup timing  : Default
Clock Source    : Internal, 1MHz

External Crystal upto 16MHz. Rest of the options : Default.Factory Default Settings for ATtiny13.

H fuse:
Self programming: Disabled
debugWire       : Disabled
Brown-out detect: Disabled
Reset Disabled  : Unprogrammed (Reset pin is enabled)

L fuse:
SPI Programming : Enabled
EEPROM Preserve : Unprogrammed (EEPROM not preserved)
Watchdog        : Off
Clock div by 8  : Enabled
Startup timing  : Default
Clock Source    : Internal, 9.6MHz

Internal 4.8MHz oscillator, Divide clock by 8. Rest of the options : DefaultInternal 9.6MHz oscillator, clock is not divided by 8. Rest of the options : Default.

Fuse programming is most crucial and any mistake might lead to non-functioning AVR controller. I have also made DOS batch files, which can be used to apply above mentioned settings with AVRdude and USBasp. You can download these files from :

AVR Dude – DOS batch files for fuse bit settings using USBasp. Archive password : mega16

http://www.megaupload.com/?d=S9BCR2RJ

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