[avr-gcc-list] Target connecting problem with JTAGICE mkII

[Eric Fu]

Hello,
 
I previously used JTAGICE mkII to download and debug ATmeg16 with STK500
and AVR Studio without problems. Now I’ve built my target board and
JTAGICE mkII failed to detect the target. I’ve checked the HW
connections and they all seemed correct. AVR Studio prompts to retry
with external reset enabled.  When I checked Yes, it stilled failed.
(The Reset signal was indeed seen on an oscilloscope). It then prompts
to use SPI to enable the JTAG interface fuse which I haven’t yet done.
 
Before I progress further, I’d like to see if I’ve missed something
fundamental.
I’m just wondering why it is OK with STK500? (I hope I didn’t damage the
ATmeg16 when I soldered it to the board)
JTAGICE mkII user’s guide indicates that it is not possible to use both
OCD and programming at the same time. Is it something to do with this? 
How can I control / toggle OCD and programming mode with AVR Studio?
With STK500, I don’t have to do anything. The code is loaded to the chip
at start-up and automatically goes into debug mode.
 
Note: The ATmeg16 is a sample supplied by Atmel. So it should come with
JTAGEN fuse programmed.
 
Thanks in advance for any helps.
 
Eric Fu