IMX6UL Reference schematic design used 470 ohm for DDR Differential clock

[ramesh6663]

Hi,

Why IMX6UL Reference schematic design used 470 ohm for DDR Differential clock termination instead of 100 ohm?

Is there any reason releated to Silicon version issue?

I have checked about this in Hardware design document, datasheet, Reference manual. But i didn't get those details?

Please help me on this.

Thanks in advance,

Regards,

Ramesh

[igorpadykov]

Hi Ramesh

in general it is necessary to follow Hardware Development Guide for the i.MX 6UltraLite

Applications Processor

http://cache.freescale.com/files/32bit/doc/user_guide/IMX6ULHDG.pdf

Seems on EVK that value was chosen to decrease power consumption.

Best regards
igor
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[ramesh6663]

HI Igor,

 Thanks for your quick response, Could you please let me know in this Hardware design guide where they mentioned the "DDR Differential clock Termination resistor value "?.

And I hope its not depends on Power consumption, It is related to Internal circuitry of DDR controller in IMX6UL processor.

Thanks & Regards,

Ramesh

[igorpadykov]

Hi Ramesh

strictly speaking it is necessary to perform ibis modelling to find optimal

resistor value, 470 ohm was found to work fine.

>Could you please let me know in this Hardware design guide where they mentioned

>the "DDR Differential clock Termination resistor value "?.

Best regards
igor