JTAG Software/UrJTAG

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UrJTAG is a dedicated JTAG tool, derived from the Openwince JTAG tools. While development of the openwince JTAG tools stalled in 2005, UrJTAG now in 2008 is under active development.

It integrates all existing patches for the openwince tools, and adds new features (like SVF player and BSDL parser) and support for new cables, even USB based cables.

The project homepage is http://urjtag.org.

Get the source

The most recent version is always available from the Subversion repository.

From time to time, a new release is made available at the SF/UrJTAG download page

However, the 0.7 release doesn't have exactly the code integrated as the special openwince JTAG tools version used here. Unless there's a 0.8 available, you should rather use the code from the Subversion repository.

You can get it with Subversion:

svn co https://urjtag.svn.sourceforge.net/svnroot/urjtag/trunk/jtag urjtag

Then compile with

cd urjtag

Interface Cable

UrJTAG works with parallel port cables such as the Wiggler. Also there's quite good support for USB cables based on FTDI chips and some more.

Board Support

Depending on your architecture, you may need to find or create a board support file.

Flash Programming

Running the following code should reprogram the flash chip. See http://urjtag.org/book/index.html for generic instructions and sample output

cable wiggler parallel 0x378
include Openwince-jtag-mpc8241.txt
endian big 
instruction SAMPLE/PRELOAD 
shift ir 
shift dr  
instruction EXTEST 
shift ir 
initbus mpc824x 
detectflash 0xFFC00000


  • You may need to run as root to access the parallel port device.
  • Be sure to specify the correct cable type. Enter "help cable" for a list of cables.
  • detect should print out a list of parts detected. If it prints out nothing then the rest of the commands will fail.
  • Double check Flash ROM and/or Information/PPCFlashROM to verify the address of the flash for your board.
  • I did not get this to work so the instructions above may be incorrect.

See Also