JTAG connection to i.MX233

Started by settuz, February 12, 2016, 09:09:38 PM

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Hello everybody!

I just received my first OLinuXino-micro board and I eager to start testing it. At first I tested it with an Arch distro and it seems to be working pretty well (of course).

Now I would like to connect it to my brand new J-Link debugger through standard JTAG interface. I read a lot of documents on this topic and I know that the standard JTAG interface is shared with the SD card pins and so on. However according to the reference manual (section 35.1.2), setting BM[3-0]="b0110" should set the processor waiting for a JTAG connection (they don't mention SJTAG here ???). I assume that the factory ROM code is in charge of detecting BM[3-0] pins and setting the proper I/O pins.

Of course I modified the original OLinuXino board in order to start from JTAG and I removed the SD card from the slot, but when I launch the GDB server it always complains that:
   "Connecting to target...ERROR: Could not connect to target."

Is there anyone which succesfully connected a standard JTAG to this processor before?
Otherwise it seems that the SJTAG adapter is the only way to get debug working on this board...   :-\ Is this adapter working also with J-Link?

Thanks a lot!  ;)


Hi JohnS,
thank you very much for the link! It seems that they already experienced the very same issue that I'm facing.

In fact the problem is that by setting BM[3-0]="b0110" should set the processor waiting for JTAG connection, but then it seems impossible to conenct through JTAG (I'm using a J-Link probe). I don't know if it's only a matter of properly configuring OpenOCD or there's also the factory ROM code which doesn't apply the proper pin-mux at boot. Anyway I'll give a try to the solutions proposed on that link and I'll let you know.

Thanks a lot!


Probably the manual+silicon work.

You might try a request for anyone who's tried it.  Guessing that the oocd ML and imx forums (if any) may work if anyone happens to be there who's done it.

I think the 233 is part of a family.  If so, maybe widen searches to the other member(s).

I suppose you found the reference to the Lyre project?  it's in https://olimex.wordpress.com/2012/06/08/imx233-sjtag-adapter-design-complete/

Possibly some hints in this (at least there's imx233.cfg), though probably not: http://www.jann.cc/2013/08/24/debugging_the_imx233_olinuxino_via_sjtag_with_openocd.html