This is the JTAG port, this is the proper pinout I believe;
1 3.3 VDC; 16 GND
2 NC; 15 GND
3 NC; 14 TMS
4 NC; 13 NTRST
5 NC; 12 NRESET
6 TDI; 11 TCK
7 GPIO 118; 10 NC
8 GPIO 39; 9 TDO

Have not been real successful in connecting via OPENOCD, any help would be great.

Chris

Brilliant! Thanks very much. I'll let you know if I have any success with openocd.

Hmm. I'm not having any luck either. I'm using this JTAG adapter. I know the adapter works as I've used it on the FreeRunner successfully.

# openocd -f openocd.conf
Open On-Chip Debugger 1.0 (2008-10-20-00:11) svn:517M
$URL: svn://svn.berlios.de/openocd/trunk/src/openocd.c $
Error: jtag.c:1291 jtag_examine_chain(): JTAG communication failure, check connection, JTAG interface, target power etc.
Error: jtag.c:1487 jtag_init(): trying to validate configured JTAG chain anyway...
Error: jtag.c:1384 jtag_validate_chain(): Error validating JTAG scan chain, IR mismatch, scan returned 0x0000
Error: jtag.c:1384 jtag_validate_chain(): Error validating JTAG scan chain, IR mismatch, scan returned 0x0000
Error: jtag.c:1384 jtag_validate_chain(): Error validating JTAG scan chain, IR mismatch, scan returned 0x0000
Error: jtag.c:1384 jtag_validate_chain(): Error validating JTAG scan chain, IR mismatch, scan returned 0x0000
Error: jtag.c:1384 jtag_validate_chain(): Error validating JTAG scan chain, IR mismatch, scan returned 0x0000
Error: jtag.c:1384 jtag_validate_chain(): Error validating JTAG scan chain, IR mismatch, scan returned 0x0000
Error: jtag.c:1495 jtag_init(): Could not validate JTAG chain, exit

Tying TDO high gives me the following which seems to again agree that the adapter is ok.

# openocd -f openocd.conf
Open On-Chip Debugger 1.0 (2008-10-20-00:11) svn:517M
$URL: svn://svn.berlios.de/openocd/trunk/src/openocd.c $
Error: jtag.c:1291 jtag_examine_chain(): JTAG communication failure, check connection, JTAG interface, target power etc.
Error: jtag.c:1487 jtag_init(): trying to validate configured JTAG chain anyway...
Error: jtag.c:1384 jtag_validate_chain(): Error validating JTAG scan chain, IR mismatch, scan returned 0x01ff
Error: jtag.c:1384 jtag_validate_chain(): Error validating JTAG scan chain, IR mismatch, scan returned 0x01ff
Error: jtag.c:1384 jtag_validate_chain(): Error validating JTAG scan chain, IR mismatch, scan returned 0x01ff
Error: jtag.c:1384 jtag_validate_chain(): Error validating JTAG scan chain, IR mismatch, scan returned 0x01ff
Error: jtag.c:1384 jtag_validate_chain(): Error validating JTAG scan chain, IR mismatch, scan returned 0x01ff
Error: jtag.c:1384 jtag_validate_chain(): Error validating JTAG scan chain, IR mismatch, scan returned 0x01ff
Error: jtag.c:1495 jtag_init(): Could not validate JTAG chain, exit

nRESET behaves as it should. The other pins, I don't know. I can't read anything happening on them with a multimeter from either the adapter or the board. I guess it's probably way too fast though, I don't have anything more sophisticated to take a reading with.

Chris, did you trace TDI and TDO directly to the CPU? Could there be something else in the JTAG chain, like perhaps the wi-fi chip?

I will have my tech today verify the connections, there must be an error in my listing as I am able to get OpenOCD to at least see the CPU but then does not go any further. I have went back and tried SVN -r 180 but that does not help and it seems even more unstable.

Chris

OK, sorry few mistakes but they have been double checked now directly to the BGA pads;

1 3.3 VDC; 16 TDO
2 NC; 15 NC
3 NC; 14 TCK
4 NC; 13 NTRST
5 NC; 12 NRESET
6 TDI; 11 TMS
7 GPIO 118; 10 GND
8 GPIO 39; 9 GND

I if anyone gets OpenOCD to work I would be interested int the config file.

Thank you,
Chris

Hmm. On experimenting some more I think the pullups and pulldowns are too strong for my JTAG adapter, it's not able to pull nRESET low enough or TCK high enough. I might try making a parallel port wiggler.

I had problems with the TCK signal as well with one of my setups, you can bias it with a resistor to 3.3 volts or you can remove the 1K(?)resistor see the photo below, there is a white arrow near the center, this is tied to ground and then makes the signal too weak. The manufacture actually specs it this way.

http://palmdr.com//eBay%20Photos/LD_JTAG_TCK_Resistor.jpg

Hope this helps,
Chris

Can you tell me how/where to trace (pdf?) the BGA to jtag on the pxa272fc5312? I have a 700p/700wx, and the only open pins I can find is a ruim slot I think. TIA