PeterChow
Newbie level 4
xilinx cpld global clock
Hi
I have got a problem during my desing process,It is about Virtex2's global clock pins.
In it's datasheet there are expressions like this:
-----------------------------------------------------------------------------------------------
The primary (GCLKP) and secondary (GCLKS) clock pads have no relationship
with the P-side and N-side of differential clock inputs. In banks 0 and 1, the GCLKP
corresponds to the N-side, and the GCLKS corresponds to the P-side of a differential clock input. In banks 4 and 5, this correspondence is reversed.
-----------------------------------------------------------------------------------------------
Now I must get differential clock output (signals: lvpecl_clk_n and lvpecl_clk_p) from Virtex2,so how should I connect the differential pins?I am puzzled with the expressions.
Suppose it is in Bank0,the differential signal lvpecl_clk_n should be GCLKP or GCLKN?
Thanks
Added after 26 minutes:
I am afraid I made a mistake,when it is used as global clock path,the direction of the global clock pins are input.So if I wanna a lvpecl differential clock from them,they can just be viewed as normal IO pins.So the P-side of pins should be connected to the P-side of the signal,and so as the N-side pins and signals.It is?Thank you.
Hi
I have got a problem during my desing process,It is about Virtex2's global clock pins.
In it's datasheet there are expressions like this:
-----------------------------------------------------------------------------------------------
The primary (GCLKP) and secondary (GCLKS) clock pads have no relationship
with the P-side and N-side of differential clock inputs. In banks 0 and 1, the GCLKP
corresponds to the N-side, and the GCLKS corresponds to the P-side of a differential clock input. In banks 4 and 5, this correspondence is reversed.
-----------------------------------------------------------------------------------------------
Now I must get differential clock output (signals: lvpecl_clk_n and lvpecl_clk_p) from Virtex2,so how should I connect the differential pins?I am puzzled with the expressions.
Suppose it is in Bank0,the differential signal lvpecl_clk_n should be GCLKP or GCLKN?
Thanks
Added after 26 minutes:
I am afraid I made a mistake,when it is used as global clock path,the direction of the global clock pins are input.So if I wanna a lvpecl differential clock from them,they can just be viewed as normal IO pins.So the P-side of pins should be connected to the P-side of the signal,and so as the N-side pins and signals.It is?Thank you.