MIMXRT1060-EVKB cannot boot up with certain condition

[niz]

Hello 

We observed an issue with MIMXRT1060-EVKB: 

We flashed the sample software provided in the MCUXpresso SDK, the LED toggling project (evkbmimxrt1060_igpio_led_output). 

Connected the 3.3V externally to pin 8 of J16. 

Then connected the mini-USB port try to power up the board

The board stuck, the red LED D6 and D1 are always on: 

The reset button(SW1) does not work in this case. 

Checked the user manual, the D6 means: 

But have no idea why that 3.3V connection could result in a reset via SDA

The only way to get rid of this state is to cut the power (unplug the USB), disconnect the 3,3V external input to the J16, plug in the USB again, the board can power up and LED starts blinking. At this time, if we plug back the external 3.3V to the J16 pin8, it seems fine and no issue. 

The problem is if we have 3,3V connected to J16 before the EVKB is powered, then if we connect the power, the board will stuck in the state shown above.  

We need to connect 3.3 V to this pin in our real application. 

Any idea/suggestion would be appreciated. 

Thanks 

[jay_heng]

Yes, this is design limitation, you can see below note in Data sheet:

Need to ensure that there is no back voltage (leakage) from any supply on the board towards the 3.3 V supply (for example, from the external components that use both the 1.8 V and 3.3 V supplies).

[jay_heng]

I will reproduce it on my side.

I believe It has something to do with OpenSDA debugger firmware update design

[niz]

Hi Jay

Thanks for looking into this issue. 

Is there any update on your side for this topic? 

Best regards 

Ni