06-13-2012 12:21 AM
I would like to use the ZYNQ Gigabit Ethernet MAC controller (GEM) in GMII mode in 10/100/1000 speeds.
For trispeed operation I need a kind of clock configuration as shown below.
Most PHY's use the dual clock GTX_CLK, MII_TX_CLK for tri speed operation.
So I need a clock MUX basically. But the GEM has a clock input EMIOENET[1,0]GMIITXCLK to the GEM only.
It seems to me I need to implement the BUFGMUX for GTX_CLK, MII_TX_CLK selection and
handle the speed switching as shown below myself?
The GEM seems not to expose interface signals as the XILINX Tri-Mode Ethernet MAC.