Help: Xilinx Virtex II Pro MGTs Reference Clock

[honghongrong]

The Xilinx XC2VP20 has eight MGTs, four Top MGTs and four Bottom MGTs. There are two external reference clock sources for the MGTs, one for Top MGTs, the other for Bottom MGTs. I only use 2 Top MGTs, must I input the bottom MGTs' reference clock?

 

[mhmhmh]

If you use only 2 top MGTs you can use only one external input. The second one is needed if you want use MGT from buttom side.

Cheers