IMX6Q is not powering up due to issue with XTALO

[alielseddeek]

Dear Community,

I am working on bringing up IMX6Q using my cutsom board but I encountered a problem.

For the crystal oscillator 24MHZ  it is supposed to connects its XTALI and XTALO to my external crystal but by mistake XTALO is connected to ground inside my board.

So I searched to know whether it will affect powering up my board or not then I found in the Hardware Development Guide for IMX6Q document that

" Without a properly running clock, the i.MX6 will not function properly. "

I wanted to know if it will be a problem if the XTALO is connected to the ground. I also wanted to know whether this will affect powering up the IMX6Q or I could not use the 24 crystal in powering it up.

Thanks in advance

Best Regards
Ali Elseddeek

[igorpadykov]

Hi Ali

all voltages. Exceptions are given in sect.2.8 Unused analog interfaces

Hardware Development Guide.

Best regards

igor

[alielseddeek]

Thanks a lot Igor.

[alielseddeek]

That's great for the first questions thanks a lot Igor,
But for the second one could you please specify which signal to inspect by the oscilloscope, do you mean VDD_SNVS_IN, VDDHIGH_IN, VDD_ARM_IN and VDD_SOC_IN ?

And if so, What are the other voltages -that should be connected after the first four- needed to boot from sd card ?

Thanks in advance

Best regards
Ali Elseddeek

[alielseddeek]

Thanks Igor but I had a problem regarding the power up sequence as it is mentioned in more than NXP document with slightly differences as

1) In the section you mentioned (4.2.1 Power-Up Sequence) is stated that VDD_SNVS_IN, VDDHIGH_IN, VDDSOC_IN, VDDARM_IN, and POR_B should be connected in the sequence mentioned.

BUT

2) In Hardware Development Guide, Table 8-2. Board bring-up checklist, NVCC_JTAG and NVCC_DRAM are added in "....., NVCC_JTAG, and NVCC_DRAM are also critical to the i.MX6 boot up."

Question 1) So which of them is the required sequence to power it up??

Question 2) Is there anyway to check if the processor is powered up or not?

Thanks in advance

Best regards
Ali Elseddeek

[igorpadykov]

Hi Ali

sect.4.2.1 Power-Up Sequence specially mentions

VDD_SNVS_IN, VDDHIGH_IN, VDD_ARM_IN and VDD_SOC_IN

as high important in power-up sequence. After them all power supplies

should be applied, sequence does not matter.

>2) Is there anyway to check if the processor is powered up or not?

by oscillosope. Also useful to check Chapter 8 Avoiding Board Bring-up Problems

Hardware Development Guide.

Best regards

igor

[alielseddeek]

Thanks Igor for your replies.

I have two another questions,

Q1) I am trying now to power it up by using u-boot through SD card, so I wanted to confirm that my manual power up sequence is correct.

My power-up sequence is as follows:

1) Connecting all ground pins to ground.
2) Applying 3 volts on VDD_HIGH_IN and VDD_SNVS_IN.
3) Applying 3.3 volts on SD3_DAT5 .

4) Applying 1.2 volts on VDD_ARM_CAP and VDD_SOC_CAP.
5) Applying 3.3 volts on POR_B.

Q2) I also wanted to know if I should make any restrictions on the current I am taking from the power supply to the different pins.

Thanks in advance.

Best regards
Ali Elseddeek

[igorpadykov]

Hi Ali

power up sequence is described in sect.4.2.1 Power-Up Sequence

i.MX6DQ Datasheet (rev.4, 7/2015)

http://cache.freescale.com/files/32bit/doc/data_sheet/IMX6DQCEC.pdf

Regarding max. current, one can look at Table 8. Maximum Supply Currents

Best regards

igor

[igorpadykov]

Hi Ali

do you mean "24 MHZ crystal" which could not removed?

Then processor will not work.

Table 21 can be found in datasheet

i.MX6DQ Datasheet

http://cache.freescale.com/files/32bit/doc/data_sheet/IMX6DQCEC.pdf

Best regards

igor

[alielseddeek]

Thanks Igor,

Okay, in case that I solved the crystal problem, Could I do this?

Q1) Is it possible to power up the IMX6Q by entering the needed voltages by power supplies MANUALLY for testing?

Thanks in advance

Best regards
Ali Elseddeek

[igorpadykov]

Hi Ali

you can try to connect external clock to XTALI.

>Q1) Is it possible to power up the IMX6Q by entering the needed voltages by

>power supplies MANUALLY for testing?

yes, provided that power-up sequence will be followed,

sect.4.2.1 Power-Up Sequence i.MX6DQ Datasheet

Best regards

igor

[igorpadykov]

Hi Ali

24MHz produces clocks for processor core and all other

peripherals, please check CCM chapter of Reference Manual.

Without it processor will not boot.

Best regards

igor

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[alielseddeek]

Thanks Igor for your reply,

To be more specific, I had a schematics' mistake in my board which lead that XTALO pin of the IMX6Q is connected to the ground in an intermediate layer of my board, so it is nearly impossible to fix it without manufacturing a new board with the corrected schematics.

My question is:
Is there any method that could override this crystal (24 MHZ) or XTALO by using any other crystal or pin to power up my IMX6Q?

or I should re-manufacture my board to power my IMX6Q?

Thanks in advance

Best regards
Ali Elseddeek

[igorpadykov]

Hi Ali

one can apply external clock to XTALI

use Table 21. XTALI and RTC_XTALI DC Parameters

i.MX6DQ Datasheet

http://cache.freescale.com/files/32bit/doc/data_sheet/IMX6DQCEC.pdf

Best regards

igor

[alielseddeek]

Thanks Igor for your reply but I think that I was not clear enough in my question last time.

To be more clear I had the external 24 MHZ oscillator connected to my IMX6Q as shown in the image while the XTALO pin grounded and it couldn't be removed unless I re-spin the board.

My questions are the following:

------------------------------------------

Q1) I searched for "Table 21. XTALI and RTC_XTALI DC Parameters" you mentioned but I couldn't find it, could you be more specific about where I could find it, please?

Q2) Could I power up the board with the XTALO pin grounded as in the image by any other modification you suggest?

Q3) Is it possible to power up the IMX6Q by entering the needed voltages by power supplies MANUALLY?

Thanks in advance

Best regards
Ali Elseddeek