On Mon, 2 Mar 2009 17:05:30 +0100 (MET) [email protected] (Joerg Wunsch) wrote:
> Yes, sure. The limitation is only that the JTAG ICE is the JTAG > master, and there can only be one master in the chain. Since each > JTAG ICE (or AVR Dragon, for that matter) can only talk to one AVR at > a time, it can only debug one. The other one is simply acting as a > shift register, passing the other device's JTAG commands through, > without being addressed by them. Ah great :-) > Just remember, while for plain JTAG programming, you can drive the > JTAG clock as fast as possible (subject of the limitations of the > passive circuitry around, see David Kelly's cable length issues), for > debugging, you have to obey the fCPU/4 rule again for the JTAG clock. Well I guess that's not a problem, since when debugging you are not transfering big chuncks of data no ? You are just sending commands and reading/writing variables. So no matter how slow the link, it will still be pretty much real-time since pressing on a button on my keyboard to step the program, or pressing the enter key to read/write a variable, will take much more time than JTAG needs to perform the operation... -- Vince, just opened his mail box... received 3 brand new Mega32, in case I blow one again ! ;-) _______________________________________________ AVR-chat mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/avr-chat
