I would like to make JTAG in order to be able to debug ATmega2560 and debug/program ARMs in the future, with in devices voltage range from 1.8V to 5.5V (probably only 3.3 and 5.0V).
There is many available circuits, from plain to MCU based, with 25 pin, 9pin and USB connectors with PC. The only variant I can't use is with 25pin connector. RS232 can be handled on laptop only trough FTDI based converter. On desktop there is native serial port with the proper chipset work with full voltage signals between -15V and +15V, i.e. respecting fully RS232 standard.
Does JTAG will work through FTDI based USB-RS232 converter?
What would be recommendations for the circuit which would satisfy these minimum requirements and can be done easily?
What freeware software can be used with JTAGs on Linux (both, debugging and programing feature, currently related with ATmega2560 only)?
I'm aware ATMEL Studio 7 can work with JTAGs, however, still there is no Linux version available.
Thanks in advance.