Debugging iMX233-OLinuXino with OpenOCD and SJTAG Tutorial


Christian Jann posted wonderful tutorial how to setup OpenOCD and SJTAG to debug iMX233-OLinuXino.

Reading the post I see Christian had no SJTAG and borrowed one from a company, we are going definitely fix this and next week will send him one of our iMX233-OLinuXino-NANO which now is assembling and iMX233-SJTAG so he could continue with his interesting tutorials 🙂



iMX233-SJTAG is serial-to-parallel JTAG converter which allow iMX233 processors to be debuggged with ordinary 20 pin JTAGs like ARM-USB-TINY-H, ARM-USB-OCD-H etc by only two pins.

All of our iMX233-OLinuXino boards have provision for SJTAG connection just the female connector is not populated as only few would need to debug RTOS with hardware debugger.

Everyone have chance to win iMX233-SJTAG today if answer correctly to our Quiz question.

Today at 17.00 o’clock our local Bulgarian time (GMT+2) we will post on Twitter our question.

You have one hour to reply to our tweet with the correct answer.

At 18.00 o’clock we will count the correct answers and ask to generate random number in range then anнounce the winner and ship the board by airmail next Monday.

Good luck!

iMX233-SJTAG adapter design complete


OpenOCD supports iMX233 JTAG debugging, the scripting support is available from the Lyre project.

Using parallel JTAG though is tricky as the parallel JTAG signals are shared with SD-CARD SPI signals and if you use parallel JTAG signals you lose the SD-CARD. Without SD-CARD you can’t boot the linux image, then what we do?

iMX233 have nice serial JTAG lines which use just two signals to do JTAG debugging without messing with the other ports, but for this purpose you need to buy the expensive USD 300 SJTAG adapter from Freescale.

As iMX233-OLinuXino number of developers increase with every day we decided that we should release low cost alternative to Freescale SJTAG. We can’t release this design as open source as we received private programming logic from Freescale under NDA, so the best we can do is just to produce this adapter at low cost and make it affordable for all OLinuXino developers.

The design is complete and we run few prototypes to validate the design, if everything works well, these will be available for sale in July.