iMXRT: No Connection with Serial Downloader

[Sam_ECU]

Hello,

I've my first custom board with the MIMXRT1062DVJ6B chip and I'm unable to connect to the chip over Serial Downloader and MCUBootUtility.

When "BOOT_MODE_0" is pulled up, my computer recognises there's a connection, but with the error "Unknown USB Device: Descriptor request failed"

My computer has no issue recognising 1060-EVK and 1010-EVK.

The Power, POR_B design is carried over from the 1060-EVK. The board is using the Flash from 1010-EVK (W25Q64JVSSIQ).

Powering and start up appears fine. There was originally an issue with the power supply to NVCC_SD1 but that has been resolved.

I noted that VDD_USB_CAP = 2.36V, but the 1010-EVK is 2.64V.

I've tried to connect with UART as well but there is no connection. I measure 3.33V on UART_TX and UART_RX although in the design they are both open.

What can be the sources for this issue?

Thanks.

[weidong_sun]

Dear @Sam_ECU ,

Welcome!

Since the question in the post has been discussed clearly, could you please press "ACCESPT AS SOLUTION" to close the case?

Thanks!

Regards,

weidong

[youngSheldon]

Here's my POR. Basically a simplified version of the EVK schematic for 1010 that takes care of the powerup sequence (R & C values). Serial connection works like a charm.

A few notes though:

• The board I had problems with was handsoldered so I redesigned it a bit and had a FAB do the assembly
• I had some issues with a Micron FLASH which I changed.
• UART works fine. USB is recognized now but I didn't manage to do a programming yet. Sinde UART works, I didn't spend time on it.
• I am using NXP-MCU Boot Utility which seems to be developed by a NXP employee
• NXP's support on this was close to zero.

[Sam_ECU]

Hello @youngSheldon 

Cheers for your input.

Glad you resolved your issues.  I still can't say where my issues lie.

According to the hardware development guide:

And the reference manual:

The power up (measured) fulfills the requirements.

I can also short the POR_B pin to ground during power up and then remove the ground and the issue remains the same, so I'm not convinced the issue lies in POR_B.

Boot_Mode(0) is 3.3V when the POR_B goes high.  Boot_Mode(1) is 0V.

I've no idea, where the issue lies...

[anthony_asterisk]

I'm having a similar problem, did you find a solution?  @Sam_ECU @nxf77486 

[youngSheldon]

I'm having a very similar issue with iMXRT1010 on a custom board. I can program the board via JTAG, but when USB is connected the system blocks (looks there is an advice on this in this post).

USB and UART programming both fail. I tested pretty much everything, every single component and connection and I am quite sure there is something in MCU that slips between my fingers. My VDD_USB_CAP is 2V6, same as on EVK.

[nxf77486]

Hello,

Thank you for contacting NXP support.

Can you please help me by trying this configuration on our MCUXpresso Secure Provisioning Tool, also as far as I understand you are booting the application from the RT1010? If this is not the case please let me know.

Regarding voltages I also recommend to give a look into the hardware development guide.

[Sam_ECU]

Hello @nxf77486 

My board has the MIMXRT1062DVJ6B chip.

There is still no connection when using the Provisioning Tool (USB or UART):

The measured power voltages all conform to those required in the Hardware Manual.

How should I best proceed to determine why's there no communication to the chip on my board?

Thanks,
Sam

[nxf77486]

Hello,

Thank you for the information, can you please help me by confirming that the set-up of the pins are set for SD so you can be able to flash the device as you are trying to do.

[Sam_ECU]

Hello @nxf77486 ,

BOOT_MODE_0 is pulled up to 3.3V.

BOOT_MODE_1 is floating.  I've pulled it down to ground as well but it makes no difference.

[Sam_ECU]

Hello @nxf77486 

I can flash the chip using MCUXpresso.

I've measured the power up below and referenced it with the information in the "Hardware Development Guide":

BOOT_MODE_0 is connected to F11 with 3.3V. BOOT_MODE_1 ist connected to G14 and floating.

BT_CFG_(x) are all pulled low.

I still can't access the chip over UART or USB in Serial Download mode.

Any and all help appreciated.

Thanks,
Sam

[nxf77486]

Hello,

I understand thank you for the information.

Can you please help me confirm the LPUART channel you are using, for the serial download you must use the LPUART1.

Please help me verify this.

[Sam_ECU]

Hello @nxf77486 

[nxf77486]

Hello,

I appreciate the information and the image send.

According to the following community post clients that are willing to use the UART it is recommended to unplug USB OTG as this is not allowed can you please he me with this test.

[Sam_ECU]

Hello @nxf77486 

That's not the issue.

Likewise with no UART attached and only connecting USB

[Sam_ECU]

Hello @youngSheldon & @anthony_asterisk 

No, I haven't resolved the issue.

I redesigned the board with an update to the POR_B.  I changed the flash to that from the 1060-EVK.

Still the exact same issue.

The help from NXP has been next to useless.

Have you managed to resolve your issues?

Cheers,

Sam

[Sam_ECU]

My POR_B Design:

[Sam_ECU]

@diego_charles @DanielRuvalcaba 

Could you help me with this issue?

[weidong_sun]

Dear @Sam_ECU ,

It seems that your USB/UART issue has not been resolved yet. 

We can continue to discuss it. 

Would you mind sharing your full schematic with me?

My email is : weidong.sun@nxp.com

Let me check the schematic firstly, then continue to discuss it with you, OK?

Thanks!

Regards,

weidong

[Sam_ECU]

Hello @weidong_sun ,

I sent you an email.  Thanks for looking into the issue.

Regards,

Sam

[weidong_sun]

Dear @Sam_ECU ,

See below, please!

Since you want USB OTG1 to be device mode, ID pin can't be floated, it should be connected to GPIO_AD_B0_01 pin of RT1062, and internal pull-up resistor should be enabled, otherwise external pull-up resistor should be used.

Next, I will check your UART1 circuit.

Thanks!

Regards,

weidong