High voltage programming to enable DebugWire.?

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I read the following under "known issuse" in the manual for JTAGICE mkII.

"debugWIRE communication is lost when part code forces the part into reset. BOD, WDT or other reset sources cause the part to lose debugWIRE communication. High voltage programming is required to get communication re-established."

Does this mean that is I use debugWire and get some of the above reset causes, my part is destryed? Or that is actually "high voltage programming" I think on it as parallell programming that must be done in a ZIF socked and not in the target using ordinary ISP.

I wanted to make an application with the ATmega168 that puts the device in power-down mode in idle time and letting the watch-dog wake it up. This will be much more power efficient than using idle mode. But if the above is correct I will not be able to debug my program. A possibility is to use idle mode during debugging but I must still be able to re-enable debugWire without desolder the device.

My favorites:
1. My oscilloscope, Yokogawa DLM2024.
2. My soldering iron, Weller WD2M, WMRP+WMRT.
3. JTAGICE3 debugger.

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I am unaware of this problem, but I use power-save mode with a watch crystal on timer2. It does use a little more current, though.

That said, I have had code on the 168 that inadvertently caused a reset (unassigned interrupt), and this did not cause me to lose debugWire contact. I have done things which have disabled debugWIre, and if the part was a surface mount part, I had to unsolder it an put another part in its place. If it was a DIP in a socket, I was able to reprogram it with HV program it in a SK500.

For your information, what I did was shut off SPI in the power reduction register (PRR). It turns out that SPi must be enabled for debugWIre and ISP to work.

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This is also from "known issuses"...:

"The PRSPI bit (Power Reduction Serial Peripheral Interface bit) in parts with PRR register (Power Reduction Register) must not be written to 1. If this bit is written to 1 it will disable the clock to the debugWire module and all communication between the JTAGICE mkII and the debugWire interface will stop. Currently this bug is present in Atmega48/88/168."

So my question about the WDT reset is still unanswered.

My favorites:
1. My oscilloscope, Yokogawa DLM2024.
2. My soldering iron, Weller WD2M, WMRP+WMRT.
3. JTAGICE3 debugger.