When I connect the jtagusb to target board(mega128), the LED is on, then in AVR studio I clicked the connect to programmer button, after I choose JTAGICE, the LED goes off. Seems it’s the only problem, them the fuse window still shows and I still can program the fuse. when I closed the JTAGICE window, it is still off.
Could anyone tell me why or it is normal? because now Im debugging my TWI communication, the program is stucked in sending start condition, I checked everywhere and there are no problem, now Im suspect if it is because of JTAGUSB, may be because it is not working at all.
It seems that you have the same problem as I have.
You don’t write which programmer or debugger programs you use.
My system set up is as follows:
Linux (Ubuntu)
Headboard with an ATmega128 chip
AVR-USB-JTAG debugger and programmer
AVRDUDE version 5.4 programmer software
I don’t have good explanations of the problem but if you have found out about a solution/explanation since you posted this message I would like to hear it.
I did some reading of old post in this forum which made me much clever. If the AVR-USB-JTAG is only used as programmer it should be disconnected when the program has been transferred to the chip since it holds the ~RESET low, why the CPU cannot start executing the program.