XGMII interface

[yifeng zhou <zhuifeng0426 () gmail com>]

Dears:

As in IEEE 802.3 clause 46, in 10G Ethernet, RS and PCS may use XGMII
interface to inter-connect.

XGMII interface is a 32-bit wide, transmit & receive data path, working on
frequency of 156.25HZ. So, for transmit direction, the total transmit rate
should be 32*156.25=5Gbps, how 10G works with this interface?

Further, on PMA,  the transmit rate become 312.5M characters per lane.. how
done this number come?

thanks!