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Contributor
Contributor
9,696 Views
Registered: ‎10-21-2010

What's the necessity to use ibuf component ?

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Hi,

 

I am creating a project on a Virtex II pro. I have a question concerning the use of IBUF component. In my project I don't use it, however my project works properly. My question is, is it necessary to instantiate IBUF and OBUF to avoid problem in the future ? what's the necessity of that ?

 

Thanks by advance

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1 Solution

Accepted Solutions
Instructor
Instructor
12,841 Views
Registered: ‎08-14-2007

Re: What's the necessity to use ibuf component ?

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In most cases you don't need to instantiate IBUF components.  I've found that the only

reasons I need to instantiate them is either because XST tries to insert more than one IBUF

on a single input (usually a DCM-related issue) or because XST doesn't infer differential

input buffers, so you need to instantiate IBUFDS components.  By the way, Lattice tools

don't require you to instantiate differential buffers.  Differential I/O's are treated like single-ended

using only the positive side of the pair.  Defining the IO standard as something differential

forces their tools to infer the differential buffer and assign the negative side of the pair.  In

both the case of Lattice and Xilinx, the parts have only one choice to place the positive vs. negative

part of a differential pair, so there's no reason Xilinx couldn't do something similar.

 

-- Gabor

-- Gabor
6 Replies
Xilinx Employee
Xilinx Employee
9,693 Views
Registered: ‎01-03-2008

Re: What's the necessity to use ibuf component ?

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Your synthesizer is adding the IBUFs and OBUFs automatically to your design.

------Have you tried typing your question into Google? If not you should before posting.
Too many results? Try adding site:www.xilinx.com
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Scholar drjohnsmith
Scholar
9,680 Views
Registered: ‎07-09-2009

Re: What's the necessity to use ibuf component ?

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Hi

 

I work on premise I;m a control freak,

  so instnatiate what I want,

 

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Historian
Historian
9,677 Views
Registered: ‎02-25-2008

Re: What's the necessity to use ibuf component ?

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@drjohnsmith wrote:

Hi

 

I work on premise I;m a control freak,

  so instnatiate what I want,

 


Why make things so difficult?

 

----------------------------Yes, I do this for a living.
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Scholar drjohnsmith
Scholar
9,672 Views
Registered: ‎07-09-2009

Re: What's the necessity to use ibuf component ?

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one word answer,

 

   predictability.

 

just my way of doing things,

 

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Instructor
Instructor
12,842 Views
Registered: ‎08-14-2007

Re: What's the necessity to use ibuf component ?

Jump to solution

In most cases you don't need to instantiate IBUF components.  I've found that the only

reasons I need to instantiate them is either because XST tries to insert more than one IBUF

on a single input (usually a DCM-related issue) or because XST doesn't infer differential

input buffers, so you need to instantiate IBUFDS components.  By the way, Lattice tools

don't require you to instantiate differential buffers.  Differential I/O's are treated like single-ended

using only the positive side of the pair.  Defining the IO standard as something differential

forces their tools to infer the differential buffer and assign the negative side of the pair.  In

both the case of Lattice and Xilinx, the parts have only one choice to place the positive vs. negative

part of a differential pair, so there's no reason Xilinx couldn't do something similar.

 

-- Gabor

-- Gabor
Contributor
Contributor
9,617 Views
Registered: ‎10-21-2010

Re: What's the necessity to use ibuf component ?

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Thank you very much for this explanation !

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