I.MX28 boot problem

[nic87]

Hello,

I'm currently working on a custom board with an IMX28 and everything worked perfectly until now.

I have recently noticed some boot issues on a few percentage of boards ( 10-20 % ) .

I first have suspected an SD issue ( the Bootloader and the Linux are in a SDcard)  but after verification the SD0_Power doesn't allow supply to the SDcard when the problem appears. 

So the problem is before...

I looked at my Bootmode resistors and i saw that the VDDIO given by the IMX28 is only 1,95V.  VDDA and VDDD are correct.

This problem is not constant on these boards which often boot correctly.But when it appears, this happens 4-5 times in a row.

When the processor boots correctly, VDDIO is 3,45V.

I have a few components powered by VDDIO but the global consumption is not really high so I don't get where the problem  is.

I power the I.MX28 with a 4,2V power supply on DCDCBATT.

If someone has already seen this problem, I'd be happy to have some informations.

Best regards!

[art · Accepted solution]

Please check your power supply connection against the Section 4.1.1.1 "DCDC_BATT source only: hardware configuration" of the AN4199 "Using the i.MX28 Power Management Unit and Battery Charger" App Note, available on the i.MX28 Documentation web page:

http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=i.MX287&fpsp=1&tab=Documentation_Tab

The most likely cause of the problem is wrong connection of some power lines, e.g. floating BATTERY pin, missing bypass capacitor on the VDD5V pin etc.

Have a great day,
Artur

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[lategoodbye]

Hi Nick,

i don't have a clue about your problem, but it would be helpful if you write down:

What kernel version do you use?

What specific bootloader do you use?

Is the bootloader configured for DCDC_BATT like in AN4199?

Stefan