Re: [avr-chat] Trouble with ATMEGA 1280 extended fuse byte

[Bernard Fouché]

Hi Eric.

I've no direct contact with Atmel at this time. FYI I checked another 
brand new ATMEGA1280 and it shows the same problem. Setting bit 3 to 
zero fixes this issue as the new value is accepted by the target.

Regards,

 Bernard

Eric Weddington wrote:
> Hi Bernard,
>
> Your best bet is to send this issue to avr AT atmel.com and see if they know
> what's going on here.
>
> Thanks,
> Eric Weddington
>
>
>   
> > -----Original Message-----
> > From: address@hidden
> > [mailto:address@hidden
> >  On Behalf Of Bernard Fouché
> > Sent: Monday, August 20, 2007 5:47 AM
> > To: address@hidden
> > Subject: [avr-chat] Trouble with ATMEGA 1280 extended fuse byte
> >
> > Hi List.
> >
> > I have the following problem:
> >
> > - I use an "ATMEGA1280 V 8AU 0622".
> >
> > - ATMEGA1280 data sheet (2549K-AVR-10/07) says (table 151, page 343)
> > that only the lower 3 bits of the extended fuse byte can be
> > programmed
> > and all other bits should be '1'. IMHO it means that
> > acceptable values
> > are from 0xF8 to 0xFF.
> >
> > - When I try to set my fuses to 0xFD (to have Brown-Out
> > Detection (BOD)
> > at 2.7volts, see table 27 page 60), avrude complains that
> > while it wrote
> > 0xFD, it reads 0xF5.
> >
> > - When using AVRSTUDIO4, I also read 0xF5 for this fuse byte.
> >
> > - 0xF5 is 11110101 -> bit 3 is zero, not one.
> >
> > Did I miss something obvious or is the datasheet wrong? If
> > so, what bit
> > 3 means ?
> >
> > Thanks!
> >
> >   Bernard
> >
> >
> > _______________________________________________
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> > http://lists.nongnu.org/mailman/listinfo/avr-chat
> >
> >     
>
>
>