Not meet some recommendation with i.MX6D

[ko-hey]

Hi all

I'd like to get your thoughts on my problem.

My customer built custom boards that is over 10 with i.MX6Dual and had some issues.

The issues are as below.

• Some boards failed booting from SD
• Some boards success booting from SD only when repeat push reset switch
• A boards failed booting from NAND

These boards can boot from serial boot.

When they test a platform_SDK and DDR Stress Test, it has no error.

The concern is that the board isn't satisfied with the location of the bulk capacitor recommedation.

From the above results, I guess that it is caused by lack of meeting some recommendation.

So if they satisfy some recommendation, the issues will be disappeared.

What do you think about it ?

Please tell me your opinion.

Ko-hey

[igorpadykov · Accepted solution]

Hi ko-hey

you are right, not following bulk capacitor placement recommedations

may lead to described issues.

Recommended to place the various sized CAPs, where as the larger sized bulk

CAPs  are further out and the smaller  high freq CAPs (0.22 uF) are closest to the

power balls as possible. To satisfy stability requirements over process and

temperature conditions one needs to follow EB814:

http://cache.freescale.com/files/32bit/doc/eng_bulletin/EB814.pdf

Best regards

igor

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[ko-hey]

Hi Igor

I understand logically but I can't proof it.

How can I proof it ?

Ko-hey

[igorpadykov]

Hi Ko-hey

one can hand solder capacitors directly under center of chip. 

Best regards

igor

[ko-hey]

Hi Igor

Thanks.

Ko-hey

[ko-hey]

Hi Igor

Let me confirm one thing.

Could you tell me the measurement conditions of equipment ?

Ko-hey

[igorpadykov]

Hi Ko-hey

measurement conditions are common: measure with multimeter

as close to processor pads as possible.

Best regards

igor

[ko-hey]

Hi Igor

I'm sorry in insufficient explanation.

I want to know a recommend equipment condition such as sampling freq of oscilloscope and type of probe.

What conditions do you measure the ripple on voltage rail in freescale ?

Ko-hey

[igorpadykov]

Hi Ko-hey

I do not have such data, sorry. But one can use any oscilloscope,

there are no special requirements for it.

Best regards

igor

[ko-hey]

Hi Igor

OK! Thanks!

Ko-hey