AVR dragon question

[Daniel O'Connor-2]

Hi,
Can someone tell me exactly what the AVR Dragon does for JTAG debugging?
The info file from Atmel says it has JTAG & debugWire "emulation
interfaces" but I don't really know what they mean by that :)

I'd _like_ a JTAG MkII but my funds don't stretch that far :)

Thanks.

--
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
GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C


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[Joerg Wunsch]

"Daniel O'Connor" <darius@...> wrote:

> Can someone tell me exactly what the AVR Dragon does for JTAG
> debugging?  The info file from Atmel says it has JTAG & debugWire
> "emulation interfaces" but I don't really know what they mean by
> that :)

That's the debugging interface.  It's called emulation for historical
reasons (JTAG and debugWIRE debugging have replaced the much more
expensive emulators that were used instead previously).

The JTAG debugging limitation is devices <= 32 KiB of flash ROM, no
Xmega (so far?), no AVR32 (so far?).  Note that AVRs > 32 KiB of flash
ROM can still be programmed through JTAG nevertheless.

--
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[Daniel O'Connor-2]

On Sat, 29 Mar 2008, Joerg Wunsch wrote:
> "Daniel O'Connor" <darius@...> wrote:
> > Can someone tell me exactly what the AVR Dragon does for JTAG
> > debugging?  The info file from Atmel says it has JTAG & debugWire
> > "emulation interfaces" but I don't really know what they mean by
> > that :)
>
> That's the debugging interface.  It's called emulation for historical
> reasons (JTAG and debugWIRE debugging have replaced the much more
> expensive emulators that were used instead previously).

OK.

> The JTAG debugging limitation is devices <= 32 KiB of flash ROM, no
> Xmega (so far?), no AVR32 (so far?).  Note that AVRs > 32 KiB of
> flash ROM can still be programmed through JTAG nevertheless.

Sounds good, thanks for the info. I see avrdude & avarice support it
which is going to be handy :)

Thanks for the info Joerg.

--
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
GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C


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