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i.MX6Q DQS gating calibration question

Question asked by Apollo Chang on Dec 10, 2018
Latest reply on Dec 11, 2018 by igorpadykov

Hi All,

 

We alrways use DDR calibration tool to get some value.

 

But why Final Value is "End-0.5*tCK:" not "Mean" ?

 

 

 

Example

 

BYTE 0:

 

    Start:         HC=0x01 ABS=0x1C

 

    End:         HC=0x04 ABS=0x5C

 

    Mean:         HC=0x02 ABS=0x7B

 

    End-0.5*tCK:     HC=0x03 ABS=0x5C

 

    Final:         HC=0x03 ABS=0x5C

 

BYTE 1:

 

    Start:         HC=0x02 ABS=0x18

 

    End:         HC=0x04 ABS=0x4C

 

    Mean:         HC=0x03 ABS=0x32

 

    End-0.5*tCK:     HC=0x03 ABS=0x4C

 

    Final:         HC=0x03 ABS=0x4C

 

 

 

 

 

DQS calibration MMDC0 MPDGCTRL0 = 0x034C035C, MPDGCTRL1 = 0x03480340

 

 

 

DQS calibration MMDC1 MPDGCTRL0 = 0x03680370, MPDGCTRL1 = 0x035C0324

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