RT1176 startup incorrectly, serial boot problems

[_And_]

I have a special board with RT1176 and it doesn't seem to boot correctly.

When I start the device and try to connect USB, it is detected as an unidentified device. and in serial bootloader and internal boot, D+ just goes up to ~3V (As far as I understand, in internal boot it should not respond to USB at all.)

There is no connection via UART1 either, it does not respond to packets from the RX line, TX is always at a low level

It is not clear whether there is a problem with the USB part or the processor itself is not booting correctly. The power sequence is as specified in section 4 of the datasheet.

BOOT_MODE[1:0]=01 (external pull-up/pull-up)

Are there any other nuances regarding the enable and activation of the serial downloader mode?

Also maybe there is some possibility of determining in which part there is a problem (power, memory, USB part..)?

[_And_]

- the power sequence seems good 

- BOOT_MODE[1:0] is equal to 01, but as I wrote before, it seems that regardless of 01 or 10, it starts in an incomprehensible mode

are there any other requirements to launch serial mode? or maybe the microcontroller has some sensitive circuits at startup that need attention?

I try with MCUBootUtility Tool connect to MIMXRT1170 EVKB and it works, but on my own board I encountered a problem (basically the schematic is taken from the evaluation board). Maybe you have some advice on how to narrow down the search for the error? and what could be the reason that the USB seems is activated but does not try to communicate?

[mayliu1]

Hi @_And_ 

Thanks for your update information.

Based on the situation you described in previous post, I suggest that you

check whether the board can powered on successfully.

1：Did you add 1ms R/C delay  in your board design, it is very import.

2: Please use an oscilloscope to test voltage about these pins in the following Fig, especially  the VDD_SOC_IN pin .

 If your board  BOOT_MODE[1:0]set as 01(Serial Downloader),  and power on successfully(Voltage range and power  on sequence), 

Open MCUBootUtility Tool, LPUART1 or USB should be available. 

Wish it helps you.
If you still have question about it, please kindly let me know.

BR

mayliu

[mayliu1]

Hi @_And_ 

Thank you for your interest in the NXP MIMXRT product, I would  like to provide service for you.

First ,I  suggest  check your hardware design first.

Please refer to MIMXRT1170 EVK board design, check  the difference between your design board  and MIMXRT1170 EVK board.  Especially  pay attention to "When internal DC-DC is enabled, external delay circuit is required to delay the DCDC_PSWITCH signal 1 ms after
DCDC_IN is stable".

https://www.nxp.com/webapp/Download?colCode=MIMXRT1170EVKHUG

Second,  Please make sure  set BOOT_MODE[1:0] Pins as 01 before power on, 

you can use MCUXpresso Secure Provisioning Tool or NXP-MCUBootUtility Tool to test your board.

Wish it helps you.
If you still have question about it, please kindly let me know.

BR

mayliu