06-22-2009 12:20 PM
I need to design an application on our board that will interface to Gigabit Ethernet as well as SATA. Only I have one reference clock available that can be 100 or 125 MHz. I have seen that for SATA typically a 75 or 150 MHz reference clock is used and for Gigabit Ethernet a 125 MHz reference clock is used.
Do you think that it is possible to have both interfaces working using a single 100 MHz reference clock?
Thanks for your help.
06-22-2009 12:38 PM
SATA 1.5 gbs uses 75MHz and SATA 3.0 gbs uses 150MHz clock, given that you have a DWORD interface to the Serdes.
GbE uses 125MHz clock for 8-bit interface. Note that if you want to support 100 or 10 Mbs, the clock is going to be 25 or 2.5 MHz.
It's possible to derive those clocks from the same reference clocks using more than one DCM/PLL .