Anyone successful with ARM922t + JTAGKEY + OpenOCD?

Development Boards MicroMod
1

Hi,

By ARM922t, I specifically mean KS8695PX. I have had the same problem with other folks in the forum, getting the same “Error validating JTAG scan chain, IR mismatch” error message. I have tried their methods but to no success. Can anyone help out a bit? Thanks!

Here’s a list of noticeable problems …

  1. I tried getting the IR id thing using the Amontec’s demo tool … but both the DR and IR chain return only FF FF FF FF.

  2. It doesn’t seem to be able to halt the CPU and enter debug mode using openocd.

  3. SRST reset with the demo tool works well, but nothing else works.

  4. I’ve tried my AT91R40008 refenece board and it works fine. Does it have to do with the CPU architecture (ie. ARM922t)? Do they handle JTAG differently?

Thanks

2

The ARM922t is very similar to the ARM920t, and afaik the OpenOCD has been successfully tested with a ARM922t based system. At the very least, debug entry, register access etc. should definitely work.

Your problem is most likely caused by the KS8695PX or the board you’re using. Do you have schematics for your board available?

Something that you can always try if JTAG communication failed is lowering th speed (by increasing the jtag_speed value).

Regards,

Dominic

3

Hi,

Do you have a email address so that I can send you the schematics?

The wiring looks generic to me though. nTRST, TDI, TMS, TCK and nSRST are all pulled up to 3.3V with 10K resistors. This is a standard 20-pin header, and pin 11 → GND, pin 17/19 → NC. Pin 1/2 → VCC, rest to GND.

I’ve also tried different speed and no success.

Thanks!!

4

Hi garlicman,

Please send me a copy of the schematic to laurent DOT gauch @ amontec DOT com. I could tell you if there are possible mistakes between your board and the OpenOCD + Amontec JTAGkey .

Regards,

Laurent

http://www.amontec.com

5

Hi to everyone who reads this thread,

The problem I have been encountering has been solved.

Thanks to Laurent@Amontec and Dominic, I have gone through again with all the JTAG signals and found the TMS pin was not properly connected to the CPU. Redid the soldering and everything is fine now. Connection from GDB works fine. Now it makes you think twice before trusting another reference board eh?

Anyway, thanks for all your supports. Great products, great forum! Thanks!