[BPI-R4] SFP+ MAC specifications

Hi,

What is the specifications of the SFP+ MAC ?

The BPI-R3 MAC is fixed at 2.5Gbps allowing the PHY rate adjust to the cable link speed.

Is the BPI-R4 MAC fixed at 10Gbps or can its clock rate be varied, for example, so SFP transceivers that expect a MAC that can do 2.5Gbps can be plugged into the SFP+ slot and still work.

On r4 mac can operate in 2 different modes SGMII (lynxi pcs) for up to 2.5g like on r3 or usxgmii for 10g (xfi pcs).