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IMX28 (evk) MDC/MDIO Timing dts

Question asked by Peter Sinka on Feb 5, 2014
Latest reply on Feb 13, 2014 by Peter Sinka

Hi,

 

I was wondering if there was a way to invert the MDC of the fsl-fec Ethernet controller via a setting in the DTS file?

 

Looking at the data sheet for the LAN8720 ethernet tranceiver datasheet: http://media.digikey.com/pdf/Data%20Sheets/SMSC/LAN8720.pdf

pgs 35/55 it look like the Data should be clocked in on the rising edge of the MDC signal. With at least 10ns of setup/hold

 

However when I look at the two signals on a scope, I can see that this timing requirement is not met (looks like both MDIO and MDC are changing at the same time)

 

So I was wondering if there was any way of inverting it via the .dts file to improve the margin?

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