Re: [avrdude-dev] device signature string

[Jan-Hinnerk Reichert]

On Friday 12 December 2003 15:06, Michael Mayer wrote:
> Hi all,
>
> In AVR910 atmel specifies the byte ordering for a signature read.
> The vendor code 0x1e comes first, followed by the part family and
> the part number. But the butterfly returns them in the reverse
> order:
>
> Send: s [73]
> avrdude: Recv: . [05] . [94] . [1e]
>
> Is this a bug in the butterfly firmware or the same for a real
> avr910 and a stk500, too?

This was not the way it was specified, IIRC. Nevertheless, there have 
been AVR910 implementations that do it that way. Probably, it is the 
correct behaviour now.

At least the latest AVR910 source I have (V2.2 from May 31st 2000) 
does it like this.

So I would not expect that Atmel changes this behaviour in future 
implementations of Butterfly-bootloader ;-)

If you are paranoid, just do a check for 0x1e and reverse order, if it 
is at the end...

> As mentioned yesterday, I want to try to use the signature string
> to choose a default device, if no -p switch is given at the command
> line. It seems to be only a relativly small modification, but it is
> still work in progress.

IMHO the only problem is that the error handling must be moved from 
"main.c" to each programmer.

/Jan-Hinnerk