I am interested in the Arrow Electronics promo offer of an AVR JTAGICE mkII for $149. Hopefully this special promotion is still available (mid-May 2010) even if there is a one or two month waiting period.
I'd like to know if there are any emphatic positive or negative opinions among the users here of this product.
I have had an ICE200 in the past and found it invaluable for developing complex (at least for me) programs. But the light fragile flex-cables on my ICE200 broke. I also burned out several pins by accidentally outputting logic high to pins that were jumped to ground on the prototyping breadboard.
Having the ICE200 model obsolete devices is an annoyance, but not a real problem because the AVR core is basically unchanged since the 90S1200. What left my head spinning about the ICE200 was having no documentation on the error numbers and messages. I had no idea what caused them or how to fix them. But that's a common problem across the industry.
The great thing about the ICE200 is being able to make hundreds of small changes in the code and breakpoint matrix daily without 'wearing out' the base AVR (since there is no real microcontroller actually in the circuit).
I'm really unclear about whether JTAG 'wears out' the underlying device. Are breakpoints done by writing a special op-code directly to the flash memory? Or does each program address have a breakpoint bit that is monitored by the internal JTAG circuitry?
What is the main advantage of using JTAG over debugWire? Is the Dragon still prone to self-destruct without warning? (I've had two, and neither one lasted more than a month. I've used a case for the Dragon PCB and a powered-USB hub, with no luck). Will Atmel repair the JTAGICE mkII if it just fails without warning or reason? Does that happen often with this product?
All opinions, reasoned or extreme, are welcome.