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Explorer
Explorer
1,354 Views
Registered: ‎03-17-2011

Instantiation of OBUFT

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Hello,

 

I'd like to instanciate single ended output buffers in vivado IP integrator (with tri-state enable). I think the primitive is OBUFT.

How can I do that?

I've found the Utility buffer but it does not seem to answer my issue..

 

Thanks.

 

Sébastien.

 

--Sebastien
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1 Solution

Accepted Solutions
Explorer
Explorer
1,673 Views
Registered: ‎03-17-2011

Re: Instantiation of OBUFT

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From vivado 2018.1, the utility buffer in the IPI has been upgraded to version 2.1.

It now supports the IOBUF buffer.

No need to package the buffer anymore.

 

Sébastien.

--Sebastien
6 Replies
Scholar jmcclusk
Scholar
1,350 Views
Registered: ‎02-24-2014

Re: Instantiation of OBUFT

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This is usually done in the top level RTL of a design.   It's quite rare (and probably not recommended) to implement IO cells in the IP Integrator.

Don't forget to close a thread when possible by accepting a post as a solution.
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Explorer
Explorer
1,330 Views
Registered: ‎03-17-2011

Re: Instantiation of OBUFT

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Thanks for your reply. I know buffers are instantiated at top level.

In my case, the whole design is implemented using the IP. Event the top level.

My HDL code has been packaged and also instanciated with te IPI.

 

The utility buffer allows to add IO buffers but not all kind of buffers. If I want to manage an output buffer with a tri-state enable, I can choose the IOBUFDS but that's a differential output pair. However, I only need a single ended buffer...

In the end, that gives an error at implementation phase.

--Sebastien
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Explorer
Explorer
1,318 Views
Registered: ‎03-28-2016

Re: Instantiation of OBUFT

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All BDs generated using IPI still require an HDL wrapper.  You should instantiate the tri-state buffers in that wrapper file.  When you first generate the HDL wrapper, you will need to select the option to "Copy generated wrapper to allow user edits".  From there, you can add the tri-state buffers.  Keep in mind that you will also be responsible for any other modifications to the wrapper that are needed as Vivado will no longer auto-update the file.

 

In some cases, Vivado will automatically infer the tri-state buffers and add them to the wrapper file for you.  I'm not sure what the requirements are to get Vivado to that.

 

Ted Booth - Tech. Lead FPGA Design Engineer
www.designlinxhs.com
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Explorer
Explorer
1,315 Views
Registered: ‎03-17-2011

Re: Instantiation of OBUFT

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Ted,

 

That's indeed a way to solve the problem.

But, don't you think it's kind of weird to use the IP integrator, generate everythink in tcl or graphically and then... edit/maintain a vhdl file in the end (just for pads)?

IMHO, we should be able to use the IP integrator from top to bottom. In order to solve my issue, I dumbly packaged an IOBUF... and it works.

 

Sébastien

--Sebastien
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Moderator
Moderator
1,262 Views
Registered: ‎06-14-2010

Re: Instantiation of OBUFT

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Hello @sebo,

 

Thanks a lot for letting us know and we are glad to see your issue is resolved now.

As your issue is solved, please mark an appropriate response as Accepted Solution (more info on this can be found here: https://forums.xilinx.com/t5/help/faqpage/faq-category-id/solutions#solutions), so  the topic can be completed then. We appreciate your help.

 

Thanks in advance and have a great day.

Kind Regards,
Anatoli Curran,
Xilinx Technical Support
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Don’t forget to reply, kudo, and accept as solution.
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Explorer
Explorer
1,674 Views
Registered: ‎03-17-2011

Re: Instantiation of OBUFT

Jump to solution

From vivado 2018.1, the utility buffer in the IPI has been upgraded to version 2.1.

It now supports the IOBUF buffer.

No need to package the buffer anymore.

 

Sébastien.

--Sebastien