Debugging ATMega(32,64 or 128) MCUs - JTAG or ISP 6 pin ?

[smartcat004]

Is there anyway I can do debugging(with breakpoints/single stepping) with the ATMEL standard ISP 6 pin connector ?
Or is a JTAG the only way to do  debugging on these MCUs ? 

If any good advise/experience on ATMegaXX debugging please share.

Appreciate also if anyone can advise what is required for doing the one wire debugging.
 

[microkid]

Debugging can only done by jtag pins and not possible with isp pins.

Dragon is required to one wire debugging.

MicroKid

[chyun3]

The one wire debugging is depend on MCU.....ex:ATMega48, ATtiny461, ATtiny44,..these are the MCU that can perform one wire debugging...however before can perform one wire debug, we must use 6pin ISP to program the DWEN fuse...

For ATMega32 it only support JTAG(8 pins) debugging....

[smartcat004]

I just bought one dragon from Farnell.
Has JTAG / ISP / Parallel programming / dW  built in a small card

Unlike the STK500 which comes with bundles of cable assemblies, this Dragon comes with no USB cables, JTAG cables etc ! Need to provide own cables. 

Just a dull printed paper box wrapping the pcb board ... thats all !

Not complaining .... but rather impressed with the cost savings effort to this extent.

-- But most importantly it performs great for my AtMega32L

One more thing to mention is the Dragon only supports up to the 32K sized chips
. Probably that limitation is deliberate.

[shishishi]

USE JTAGICE DEBUG

[edaudo]

ATMega32 ... 128 only use the JTAG interface for debugging. But you need the 6-pin ISP too, to first set the JTAG enable fuse otherwise you will not be able to connect to the MCU.

The JTAG ICE is the best choice if you can aford it. The actual version is MkII (serial+USB), the older MkI (serial) does not support DebugWire for smaller chips but you sometimes can get it pretty cheap at ebay.