According to iMX7 Spec., the rise/fall time spec should not over 0.75ns.
There was too hard to meet when RGMII operation in 3.3V.
We find a document that " OPEN Alliance RGMII EPL"., the document was attached.
The shows there are operation in 3.3V, and specify maximum rise/fall time spec.is 1ns
Normaly, RGMII operation voltage is 2.5V, so rise/fall time spec. 0.75ns should not be a problem.
When RGMII operation in 3.3V, should we still follow the 0.75ns spec., or we can just make sure rise/fall time small than 1.0ns.
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RGMII and GMII are similar which use the same clock - 125MHz.
RGMII often operation in 2.5V, but GMII operation in 3.3V.
RGMII speify Tr/Tf < 0.75ns.
GMII specify Tr/Tf < 1.0ns.
We know the higher voltage needs bigger rise/fall time.
So, Should we follow the 1.0ns spec.with 3.3V operation?
Please see the attachement, there is NXP LS1088A datasheet.
There shows 1.8V/2.5V, two different rise/fall time spec which are 0.75ns and 0.54ns.
I think there will be an other rise/fall time for 3.3V operation, right?