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korayk
Visitor
Visitor
416 Views
Registered: ‎03-09-2021

LVDS Output Buffer

Hello,

I have a vc707 board. I want to send 16 bit data to FMC LVDS pins. 

However, I could not find the correct buffer for this task.

Can you recommend and give example usage of an LVDS output buffer.

I tried OBUFDS but it seems it is not the convenient one.

Thank you,

Koray

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4 Replies
bruce_karaffa
Scholar
Scholar
412 Views
Registered: ‎06-21-2017

Convenient or not, the OBUFDS is the differential output buffer.  Look at the language template in Vivado device primitive instantiations.  Why is using this buffer inconvenient?

korayk
Visitor
Visitor
329 Views
Registered: ‎03-09-2021

Hello Bruce, thanks for the reply.

I don't remember exactly but I read somewhere OBUFDS is not fast enough. Also, I can not select LVDS as I/O std when I use OBUFDS.

I thought there may be a special buffer for LVDS. 

Any suggestions?  

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drjohnsmith
Teacher
Teacher
316 Views
Registered: ‎07-09-2009

If your in Vivado,

   then the constraints file is normally used to sets the lvds and its type,

then you also have to get the bank voltages correct for it to be placed,

OBUFDS are the standard differential outputs of the FPGA, 

    how fast do you want to go ? 

The "only" faster ones are the Giga bit speed serdes blocks , but they are not LVDS as such.

 

<== If this was helpful, please feel free to give Kudos, and close if it answers your question ==>
korayk
Visitor
Visitor
277 Views
Registered: ‎03-09-2021

Thank you John. Yes I am using VIVADO. The program used to terminate itself when I tried to select LVDS. I don't remember what I changed but now everything seems OK. 

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