Re: [avr-chat] Crystals (was ATmega32 @ 16MHz : fuse bits ??)

[Dan]

Hi,

I'm new to the list but have been using Atmel for a long time.
I'm glad I found this.
This convention dates back to the first PROMs and EPROMs.
Where the cell of each data bit was actually a type of fuse which literally
gets burned (or popped) by using a higher programming voltage.
So the unprogrammed state was actually a 'closed' connection,
thus creating a logic 1 as if you the switch was closed until you opened it.
This convention has remained intact over 30yrs year now.

IIWDTI
=Dan

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Joerg Wunsch wrote:

> Vincent Trouilliez <address@hidden> wrote:
>
>  
>
> > About the fuse bits that have a reversed logic, I am not sure why
> > the data sheet keeps insisting that 0 means programmed and 1
> > unprogrammed.
> >    


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