Re: [avr-chat] Dragon: mega slow at dumping Flash, normal ?

[Daniel O'Connor]

On Mon, 29 Jun 2009, Vincent Trouilliez wrote:
> On Mon, 29 Jun 2009 00:19:17 +0200 (MET DST)
>
> address@hidden (Joerg Wunsch) wrote:
> > Vincent Trouilliez <address@hidden> wrote:
> > > Or might this be a problem in the terminal mode of avrdude,
> > > rather than the Dragon ?
> >
> > Sorry, I didn't read your message to the end at first.
> >
> > Yes, the terminal mode uses one byte at a time transfers, it's
> > terribly slow.  It's really only intended for having a quick view
> > into a few bytes of memory.
>
> Yeah but it's very fast with my crappy // port DIY cable ('bsd'
> style), it's only when using my Dragon that somehow terminal mode
> becomes super slow. That's why I am trying to find out if it's
> because of the Dragon that's crap (sorry Atmel) or if the terminal
> mode somehow has some bug that makes it slow with the Dragon, but
> fast with a DIY cable. I still have not been able to figure out which
> of the Dragon or avrdude, is at fault... so I can't take action ! ;-)

The Dragon is slow because there is a lot more protocol overhead, so 1 
byte at a time transfers are very wasteful.

On the plus side since the Dragon is smart you can transfer big chunks 
of data to it and it will do the rest at the speed you specify.

FWIW I use a Dragon (with FreeBSD) in ISP mode and I don't have speed 
problems with -U for programming parts. Although I did have to adjust 
the SCK rate at first.

-- 
Daniel O'Connor software and network engineer
for Genesis Software - http://www.gsoft.com.au
"The nice thing about standards is that there
are so many of them to choose from."
  -- Andrew Tanenbaum
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