Re: [AVaRICE-user] AVaRICE with AVRDragon and AtMEGA8u2, debugWire

[Joerg W. <j...@ur...>]

As Brian wrote:

>     got asynchronous event: 0xf7
>     recv: timeout

This is an

#define EVT_ERROR_PHY_RECEIVE_TIMEOUT       0xF7

meaning the debugWIRE transport timed out (between the Dragon 
and the target).

> So...is this something to do with telling AVaRICE it's an atmega48 when 
> it's really an atmega8u2?

Very unlikely.

Btw., when debugging an 8 KiB device (ATmega8U2), better pick another 
8 KiB device for -P, like the ATmega88.

>  Suffice it to mention that using Atmel Studio 
> under Windows works flawlessly.

Then the only way to find out is (unfortunately) to trace Atmel 
Studio's actions when initializing the AVR Dragon, and compare it 
to what AVaRICE does.

I'd more suspect the actual debugWIRE connection at first though. 
You can try experiment with pullup resistors on /RESET.  I've seen 
target working more reliably with 4.7 kΩ or 10 kΩ pullups, but 
I've also seen target working best without any additional component 
between the ICE (i.e. your Dragon) and the /RESET line.

Also make sure to use at most the standard STK500 cable length between 
the Dragon and the target (about 15 cm), as the Dragon's line drivers 
are known to be quite weak.
-- 
cheers, Joerg               .-.-.   --... ...--   -.. .  DL8DTL

http://www.sax.de/~joerg/
Never trust an operating system you don't have sources for. ;-)