I have a custom board, that is very close to the EVKB board, except no USB or MIPI. I cannot seem to access serial downloader mode to use the Secure Provisioning Tool via UART, nor obtain any access via JTAG/SWD for programming. The chip seems to be working, on that there is an ON/OFF button that when held for 5 seconds, or whatever the length is, powers the chip off, and then pressing the button again powers it on.
I've double-triple checked everything, and it nearly matches the EVKB board, however one things I noticed that was not done was to connect VDD_MIPI_* or VDD_USB_* to anything, again, as the board doesn't use MIPI or USB. Could not connecting those power pins be causing the problems I'm having with accessing UART or JTAG/SWD?
The image I posted is from that red circled area, and I am using the exact components, values as detailed in the EVKB there.
Hi @application_ninja ,
In MIMXRT1170-EVKB board , RC delay time is 30000*0.00000022=0.0066s =6.6ms.
Please check your board, if your board use the same RC delay circuit, Please use an oscilloscope to measure the signal circled in red in the image.
Best Regards
As an FYI, this is what my delay circuit looks like...
Blue being DCDC_IN and yellow being DCDC_PSWITCH.
Hi @application_ninja ,
VDD_SNVS_DIG is internal LDO output.
1: I suggest you can compare your customed board with MIMXRT1170-EVKB board, check the difference.
2: If you have MIMXRT1170-EVKB board, did you try modify the MIMXRT1170-EVKB board same as your customed board?
Best Regards
Apparently VDD_SNVS_DIG is low, and controlled by software, so my design is correct?
https://www.nxp.com/docs/en/data-sheet/IMXRT1170BCEC.pdf
"The power rail VDD_SNVS_DIG is controlled by software."
Hi @application_ninja ,
Could you use an oscilloscope to check if the power-up sequence is normal, especially the RC delay circuit?
Best Regards
MayLiu
All my power rails look good, proper voltages, my ONOFF button works, reset button, just really stumped as to why I cannot program / read the chip.
Hi @application_ninja ,
Thanks for your updated information.
First, I suggest you follow the HDUG recommended design for your customed hardware development board.
Second, please check the Boot Mode pins settings of your custom development board. If you want use the Secure Provisioning Tool via UART, you need set as serial downloader mode.
Third, Only LPUART1 support serial downloader mode.
Wish it helps you.
Best Regards
MayLiu
Yes, I am aware of that document, but that does not answer my question, and as you have confirmed what the document states, those are "recommendations", they are not listed as "requirements" for proper board operation. So going by the way you have stated and the documentation reads, as "recommended" they do not have to be performed for proper board / chip operation.
Which leads back to my question, could not doing these "recommendations" cause the problems I am seeing?
Hi @application_ninja ,
Thank you so much for your interest in our products and for using our community.
In MIMXRT1170HDUG, it describe that Unused pins recommendation
https://www.nxp.com/webapp/Download?colCode=MIMXRT1170HDUG
Please follow the Recommended connections for unused analog interfaces.
Wish it helps you.
If you still have question about it, please kindly let me know.
Best Regards
MayLiu