Comments on: Setting fuse-bits on Atmel Atmega8 AVR

By: thanks louic

thanks louic — Mon, 02 Apr 2012 20:30:40 +0000

this article really saved me .........
i thought my atmega16 won't work again
thanks man

By: louic

louic — Tue, 20 Mar 2012 15:01:29 +0000

Hi vishnu,

I don't understand your first question. All I can say about precautions is to read the datasheet and think carefully before you change fuse bits. If you know what you are doing, and double check the values before you change them there will not be a problem.

By: vishnu

vishnu — Mon, 19 Mar 2012 15:39:40 +0000

can you tell what all precautions should be taken while setting fuse bits in extreme burner

By: vishnu

vishnu — Mon, 19 Mar 2012 15:37:54 +0000

hai am doing a project on avr.i am confused.i used extreme burner instead of avr dude
1.will the fuse bits from frequency to frequency.if so what will be the fuse bits for 8,12,16 MHZ
2.i checked my atmega8 by programming with test led program,that was ok.i set the fuse bits for 16mhz as c9 and FF.then i erase the chip and burned my actual program.again i set the fuse bits will there be any problem.there was no response from my controller after then

By: Can 89S programmed using USBasp? - Page 5

Can 89S programmed using USBasp? - Page 5 — Mon, 09 Jan 2012 19:08:45 +0000

[...] i cannot write them directly in digit.. so i searched for check box values.. as per this site: Setting fuse-bits on Atmel Atmega8 AVR at Louic's blog – about science and stuff the pattern is hfuse: bit 7 6 5 4 3 2 1 0 name RSTDISBL WDTON SPIEN CKOPT EESAVE BOOTSZ1 BOOTSZ0 [...]

By: louic

louic — Tue, 10 May 2011 09:42:24 +0000

Hi taqee ahmed, It is a good idea to include such a picture, but unfortunately I do not have a lot of time at the moment. But let me try to describe it more clearly:

For the working atmega that will send the pulses: The easiest is to put this chip on your programmer board. Then connect PIN C0 to XTAL1 of the "broken" atmega.
For the broken atmega: All you need is power, ground, and reset connected, and the connection to XTAL1 as said above.

I hope this helps. More details about connecting an atmega microcontroller can easily be found with google: search for "minimal atmega schematic" or something similar.

By: taqee ahmed

taqee ahmed — Sun, 08 May 2011 00:50:22 +0000

thanks for informative article

some people doesnot have very good understanding of English

can you publish the circuit diagram for removing fuses of broken atmega with working atmega

thanking you

Bye

By: kim

kim — Sat, 23 Apr 2011 07:31:22 +0000

Hello everybody
I also build Atmega48 based external generator
it is generating signal.
But when I return crashed atmega48 or atmega8
Stk200, PonyProg doesn’t recognize my uC.
uCs still not working.

By: Programming Arduino with Arduino « Wire Jungle

Programming Arduino with Arduino « Wire Jungle — Mon, 16 Aug 2010 05:41:41 +0000

[...] Introduction and some do’s and don’ts: here [...]

By: louic

louic — Tue, 01 Dec 2009 10:34:01 +0000

Hi Marius,

The Atmega 8 manual says:

"For resonators, the maximum frequency is 8 MHz with CKOPT unprogrammed and 16 MHz with CKOPT programmed."

unprogrammed = 1
programmed = 0

So with CKOPT = 1, the maximum frequency is 8 MHz, but CKOPT = 0 will also work. The opposite is not true however: if the crystal resonates between 8-16 MHz, CKOPT has to be set to 0.

So if the crystal frequency is not higher than 8MHz, the following quote from the manual can help you decide how to set CKOPT.

"When CKOPT is programmed, the Oscillator output will oscillate a full rail-to-rail swing on the output. This mode is suitable when operating in a very noisy environment or when the output from XTAL2 drives a second clock buffer. This mode has a wide frequency range.

When CKOPT is unprogrammed, the Oscillator has a smaller output swing. This reduces power consumption considerably. This mode has a limited frequency range and it cannot be used to drive other clock buffers."

So yes, you are right that your quote from my weblog is very confusing. I changed it. Thank you for your comment!