Electronic – Programming Interface for TI DSP

I believe I may have found a two part solution for my particular problem. I currently own an Arduino Diecimila (which has the ATMEGA168 with the problem) and also a new Arduino Nano 3.0. I went ahead and flashed the Arduino Nano with the ArduinoISP firmware. I then picked up 3 28 Pin ATMEGA328P DIP chips for $5.00 each at the local electronics store.

I used the ArduinoISP to flash one of the virgin chips with the Arduino Firmware using the above link with a crystal. I plan to now flash one of the other ATMEGA328Ps with the High Voltage Programmer firmware. This chip along with a bit of wiring on a breadboard should allow me to reset all of the fuses on the original ATMEGA168. Once that is done, I will be able to use the Arduino Nano to reprogram the chip.

Since the ATMEGA328Ps only cost $5 each, my end goal is to setup one 328 as an Arduino ISP programmer, setup the 168 as a HV Programmer, keep one 328 chip in my current Arduino Diecimila (upgrade!!), and I'll have one left over for whatever. I can then either switch chips on the Diecimila or build out a real board for the ISP and HV Programmer boards.

I still have not tested the JTAG ICE MKII yet with a logic/oscilloscope. Not sure if it is the root of the problem or not. I will address this issue after I build the HV Programmer.

I will report back on the success/failure of the HV Programmer. I just need to go get a few more 1K resistors to pull it off. Anyone ever tried the HV Programmer? Any other suggestions? If nothing else, hope this helps someone.

About the JTAG, you don't need a proprietary one, unless the board you have has a proprietary connector. Even then, if you can discover its pinout you could make an adapter connector. The main difference between open/free JTAG projects and a commercial product is that the later will probably have higher speeds, which makes a big difference depending on the complexity of the programs. There are cheap commercial JTAG adapters that are parallel/serial, and somewhat more expensive ones that are USB; given the choice, I'd always prefer USB.

About the toolchain, it's perfectly possible to use GNU tools, (take a look at gnuarm.com) but the downside is that you have to find documentation about how to interface with the device-specific hardware; also you may have to prepare a specific link script for the memory map of your device. The more rare/exotic it is, the less probable it is that you'll find a script already made. And these link scripts can be pretty complicated. If you use a commercial toolchain specifically tailored for your device, you'll find everything already set to make it work on the device.

I'd also recommend to buy a dev board (like this one) for that MCU; It'll be a lot easier to make everything work if you can divide-and-conquer. And having a tested, functional board is the best way to keep software and hardware problems separated.