AnsweredAssumed Answered


Question asked by Martin Smith on Sep 5, 2018
Latest reply on Sep 7, 2018 by CarlosCasillas

I'm trying to bring up a custom PCB and want to use boundary scan to test the PCB. I have run into multiple issues!


Firstly, I can connect to the PCB and read the status all of the balls using SAMPLE mode, but when I put the device into EXTEST mode to drive the pins, the device drops out after approx. 5 seconds. I don't have the ON_OFF pin (M6) connected to anything so was wondering if this was causing the device to go into sleep because the boundary scan disabled the internal pull resistors and the device thought the ON_OFF pin was low??? Any other ideas?


I then went to the eval PCB (IMXRT1050-EVKB) and used the JTAG port (J21) to connected to the M7 on that PCB. I can't connect to it, but I have used that PCB via SWD many times.


I have pulled the JTAG_MOD pin (F13) high to put the M7 into JTAG mode and still nothing. I am beginning to think that the eFuses (specifically the DAP_SJC_SWD_SEL eFuse), or JTAG security settings are to blame but am unsure how to test or what to do about it?

HAs anyone got the eval PCB working with boundary scan???