AnsweredAssumed Answered

Boundary Scan chain fails 150ms after EXTEST instruction

Question asked by Jan Heiber on Mar 30, 2017
Latest reply on Mar 31, 2017 by Artur Petukhov


I am having trouble in Boundary Scan testing an iMX6UL device, exact number is IMX6G2CVM05AA, revision is 1.1.

When entering EXTEST mode, the scan chain breakes after about 150ms. That is enoutgh for testing the scan chain itself but not for the interconnection test and cluster tests. The iMX6 device delivers 0x0000 at its TDO pin afterwards.

It looks like a TAPRESET (TRST or entering the state) can revers the result, I suspect an internal reset.

I need to know how to make sure the device is not executing any reset after entering EXTEST instruction.


I also tried:

- loading instruction "ENABLE_EXTRADEBUG" and entering different values to address 4 and address 7 registers but without success.


I am looking forward to your soon reply Please don't hesitate to ask in case of further questions.


With best regards

Jan Heiber