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imx6 DDR calibration - U-boot or GUI ?

Question asked by Aebischer Quentin on May 23, 2017
Latest reply on May 24, 2017 by Aebischer Quentin

Hi everyone,

 

So I have been running two methods to calibrate DDR on our product (imx6Solo based board - 2x512 MB = 1GB of DDR3), the one with GUI based tool and the one with u-boot. 

 

I don't know why, but the results are quite different, especially for the Read DQS Gating calibration (MPDGCTRL0 PHY0).

 

With u-boot method, I get : 0x42280228.

With GUI based method, I get : 0x0238023C.

 

So U-boot method reports a value 29 times larger.

Also the Write level calibration (MMDC_MPWLDECTRL0 ch0) is 2,5 times bigger with GUI-based method than with U-boot.

 

I have verified each parameter passed to the aid script, and I invalidated cache in U-boot too, so I don't know what I did wrong in either method ?

 

Which method should I trust better ?

 

Regards,

 

Quentin

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