ARM Getting Started: Using USBprog and OpenOCD
Be careful (added Jan 18, 2009):
OpenOCD has updated its commands set, thus, some OpenOCD commands mentioned in this article have become obsolete. If you have download the latest source code through svn, and compiled your own OpenOCD, Please do this:
$ info openocd
to get the correct commands.
A couple of weeks ago, I bought a chip of AT91SAM7S32 from OURAVR — a local net shop and also a community for AVR/ARM related electronic design — just a chip, because I could afford neither a evaluation board nor a JTAG adapter with USB interface. (Unfortunately my laptop only have USB ports for I/O, I am unable to use a relatively cheaper Wiggler-like JTAG device.)
So, after searching in my tool box, I found the following things:
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a lot of AVR chips, including a ATMEGA32.
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USB device chips: USBN9604 and some FTDI chips, but without a FT2232 which can support USB to JTAG bridge directly.
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crystals, 74245 level shifter, solderless bread board, SMD to DIP convert boards, voltage regulator, USB socket, RCLs, adult videos, …
OK, that enough. I could make a mini development board by myself. And Benedikt Sauter provided us a wonderful tool — USBprog, I once tried it as a good AVRISP MK2 Clone. It can also be programmed as a OpenOCD adapter for programming and debugging ARM microcontrollers.
If you are acquainted with AVR microcontroller, also have a USBprog or just a USBN9604 chip on hand, this article will give you a method to play with ATMEL ARM with the following advantages:
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very low cost: less than 20 US dollars totally.
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promptly available: you can build the whole system in a weekend.