Re: [avrdude-dev] Patch for "Safemode" Support

[E. Weddington]

Colin O'Flynn wrote:

> Hello,
>
> I have created a patch against CVS that implements  "safemode".
>
> It stemmed from a dead AVR I had happen to me, and figuring out that probably 
> a databyte got corrupted which resulted in the lock-bits changing to disable 
> the external RESET pin on my AtMega. Since there are no error detection bits 
> on the AVR's programming protocol, it is possible to have changed the fuse 
> bits and not know it. However - as long as you don't exit programming mode 
> the fuse bits don't become active.
>
>  
Great! Thanks for doing this!

> You can see the thread at 
> http://www.avrfreaks.net/phpBB2/viewtopic.php?t=25596 - which includes Erik's 
> comments which are pretty much the reason I actually made the patch ;-)
>
>
> Erik summed up the idea as this:
>
>  
*cough*
s/Erik/Eric/g
:-)


> "- Before the start of every program, read the fuse settings and store.
> - Program flash / eeprom
> - Read the fuse settings again and compare to previously stored settings.
> - If different, reprogram fuse settings with previously stored settings.
> - Exit programming mode. "
>
> Which is what this patch does. The -s option enables safemode, which right now 
> prevents you from changing the fuse bits *at all*. 
>
>  

Did this actually fix your problem?

Eric