DO I need impedance for Virtex-2

[EDA_hg81]

According to datasheet, virtex -2 gets impedance control.

If this means, I do not need line termination control on PCB board?

By the way How I can refer ODDR2 and IDDR2 in VHDL?

Thanks

 

[Iouri]

What frquencyies you are running, if it relativly low you dont need it

Using "attribute" command you can se tup pin properties, i/e IO voltage, driver straingth, type of IO

 

[EDALIST]

vitex has capability to termination.
for ddr2 you will need v4 which is faster.

check xilinx app notes.

 

[EDA_hg81]

it is 200MHZ.

Do I need extre line termination for virtex-2 or sparta-3?

Thank you.

 

[Iouri]

What is trace lenght? What trace size are you using ? Is it poin to point?? How many layers?

There is no straight answer for your question, check Howard Johnos book Black Magic, or look for the Eric Bogatin books. Alos Xilinx app notes will help


Good lack with black magic!

 

[EDA_hg81]

In Virtex -2 datasheet it provides few impedance control methods.
What I am confusing is do I need extra impedance control if I have used one of those impedance control methods provided by virtex-2 datasheet?

Thank you.

 

[Iouri]

again no straight answer you might you might not. Also check the Xilinx for the development board, try to order one of those boards, and see how they behave. or simple run quick protoboard