AVR-Chat

Mega16 is 44 pin, Mega8/Mega168 is 32 pin.

Local disti has reported a number of companies routinely using debugwire, he 
didn't mention the lockout issue although.

Given the need to have to use the SPI lines for programming anyway I am leaning 
toward the well trodden JTAG solution. I would like to use a much smaller device 
but feature creep has begun & Mega8 class is the minimum family so Mega16 is a 
short hop away & cost is not an issue...


Cheers

Don

Ivan Vernot wrote:
> HI Don,
> I have used debug wire on a Tiny13.
> 
> It worked well enough (when I it worked) but I am a little disturbed that I 
> have been locked out of a few micros when things go wrong.
> 
> FWIW here is how it worked for me
> -  need to connect to regular ISP lines.
> - AVRStudio is told to go into debug wire mode
> - AVRStudio enter as 'special' ISP mode to set the debug wire fuse bits
> - Alls well and debug wire works just like JTAG (cool)!
> 
> BUT
> Before you exit you debug setting (and AVRStudio) you must remember to clear 
> the debugwire fuse bit.
> If you don't or AVRStudio crashes or AVRStudio reports that it could not set 
> the debug wire fuse bit (as was my case) then you can get locked out of the 
> micro and regular ISP no longer works nor does debug wire :-(
> 
> I don't want to appear too negative.as I have not had too much time to look 
> into this as yet (and it is possible that I screwed up something).
> 
> I have been successfully developing with debug wire for a couple of week 
> with no problems. Then, I need to (in a hurry) make a quick mod for a client 
> and in a flurry of activity I managed to lock myself out of three devices in 
> a row!!!!
> 
> I have not been able to investigate it further and it does concern me 
> but )(as I said)  I was a very happy camper 'till then.
> I am 'hoping' that I did something stupid in my rush.
> 
> HTH.
> 
> BTW: IF I'm not mistaken the mega 16 and the mega8 pin compatible? So you 
> could use the mega16 in development (and use JTAG) and then when its all 
> done recompile for a mega 8.
> 
> Cheers,
> 
> Ivan Vernot
> 
> 
> 
> 
> 
> ----- Original Message ----- 
> From: "Don Ingram" <don@led.com.au>
> To: <AVR-Chat@yahoogroups.com>; <codevisionavr@yahoogroups.com>
> Sent: Friday, March 31, 2006 10:06 AM
> Subject: [AVR-Chat] Debug wire experiences
> 
> 
>> Hi All,
>>
>> Does anyone have any comments re experiences with debugwire on JTAGII.
>>
>> I am specing a project at present which fits neatly with the Mega8 
>> derivatives
>> but am reluctant to leave the well trodden path with the Mega16 / JTAG 
>> family.
>>
>> I see very little history of conversation re debugwire and have little 
>> desire to
>> play pioneer ( the guy lying face down in the mud with the arrows in the 
>> back )
>>
>> X-posted to chat & codevision.
>>
>> Cheers
>>
>> Don
>>
>>
>>
>> Yahoo! Groups Links
>>
>>
>>
>>
>>
>>
>>
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
> 
>  
> 
> 
> 
> 


-- 
Cheers

Don Ingram


Leading Edge Design

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