AVR-Chat

I received a small Olimex development board that included a Tiny2313.
The 7805 voltage regulator is apparently bad and puts out the same as 
it's input voltage (12volts). Needless to say, I suspect that 12volts 
on the Tin2313 has zapped it.  But, I got curious and looked at the 
differences between the 2313 and tiny2313. One of the differences is 
that there is a fuse bit for the oscillator.  Being new to AVR - if 
the fuse bit is set, is it correct that that is the confiugration 
forever?  A fuse bit is just like a regular fuse, I assume. Blow it 
and it is blown.  I barely know anything about the 2313 and guess I 
need to change to the Tiny2313.....

Doug

At 09:23 PM 7/25/2005, n4ij wrote:
>I received a small Olimex development board that included a Tiny2313.
>The 7805 voltage regulator is apparently bad and puts out the same as
>it's input voltage (12volts). Needless to say, I suspect that 12volts
>on the Tin2313 has zapped it.

Almost certainly.

>   But, I got curious and looked at the
>differences between the 2313 and tiny2313. One of the differences is
>that there is a fuse bit for the oscillator.  Being new to AVR - if
>the fuse bit is set, is it correct that that is the confiugration
>forever?

Nope, fuse bits can be reset, IF you have the right programmer.
It is possible to get it into a state where the simple programmers 
can't talk to it anymore.

>  A fuse bit is just like a regular fuse, I assume. Blow it
>and it is blown.

Nope, completely eraseable. :)

On Mon, 25 Jul 2005, Dave VanHorn wrote:

> 
> >  A fuse bit is just like a regular fuse, I assume. Blow it
> >and it is blown.
> 
> Nope, completely eraseable. :)
> 

I have wondered where the term came from.  Is it a holdover from the old 
PROM fuses? I still have a couple AMD 27S27's around here somewhere that 
actually DO burn out "fuses" in the device when they're programmed.

Zack