i.MX6Q DDR3 clock problem

[cbrust]

For troubleshooting purposes, we generated a script to initialize DDR3 to use a 400MHz (instead of 533MHz) clock using the v1.9 Freescale Register Aid tool (latest as of 12/5/15).  We verified the 400MHz initialization script was indeed different from a 533MHz script generated by the same tool.  However, after using the 400MHz script to initialize DDR, the clock frequency remains at 533MHz by o-scope measurement (we saw this issue before with the old register scripting aid too).  Because the clock frequency does not change there is no way we can try a lower frequency for troubleshooting our DDR3.  Is there something additional that needs to be done in order to get the 400MHz clock frequency or is this an indication of a larger issue with our i.MX6Q?

[Yuri]

You may create SR to get some example sources how to change frequency.

Regards,

Yuri.

[igorpadykov · Accepted solution]

Hi C

generated script just calculates MMC/DDR settings but does not set CCM frequencies.

This should be done using jtag, in DDR Tester (input DDR requency) or using other ways.

So there are no indication of any  issues with your i.MX6Q.

Best regards

igor

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[cbrust]

Thanks Igor.

We figured we were missing something simple or making a bad assumption.

Cliff