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Adventurer
Adventurer
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Registered: ‎05-18-2018

How do I tell Vivado to treat signals as differential, and can I set this up in the Block Diagram editor?

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I have several fabric SPI blocks with signals that I want to be differential when they enter/leave the UltraScale+ IC.

In my block design, my MOSI and MISO signals are single-ended (I read that IP core signals are not differential), but I want the signals leaving/entering the US+ to be differential (MOSI_P/MOSI_N, MISO_P/MISO_N).

Questions:

1) How do I tell Vivado to treat these signals as differential?

2) I've read that I need to instantiate IBUFDS/OBUFDS primitives. Is this true, and if so, how do I bring these into the block diagram?

3) At what point in the design process do I need to tell Vivado these signals are differential?

 

Thanks!

single-ended_to_diff.png
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Moderator
Moderator
389 Views
Registered: ‎01-16-2013

Re: How do I tell Vivado to treat signals as differential, and can I set this up in the Block Diagram editor?

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@joelschad 

 

You can add utility buffer IP in the block diagram and customize it to be used as differential buffer. 

https://www.xilinx.com/support/documentation/ip_documentation/util_ds_buf/v2_1/pb043-util-ds-buf.pdf

 

---Syed

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Kindly note- Please mark the Answer as "Accept as solution" if information provided is helpful.
Give Kudos to a post which you think is helpful and reply oriented.

Did you check our new quick reference timing closure guide (UG1292)?
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Highlighted
Moderator
Moderator
390 Views
Registered: ‎01-16-2013

Re: How do I tell Vivado to treat signals as differential, and can I set this up in the Block Diagram editor?

Jump to solution

@joelschad 

 

You can add utility buffer IP in the block diagram and customize it to be used as differential buffer. 

https://www.xilinx.com/support/documentation/ip_documentation/util_ds_buf/v2_1/pb043-util-ds-buf.pdf

 

---Syed

---------------------------------------------------------------------------------------------
Kindly note- Please mark the Answer as "Accept as solution" if information provided is helpful.
Give Kudos to a post which you think is helpful and reply oriented.

Did you check our new quick reference timing closure guide (UG1292)?
---------------------------------------------------------------------------------------------

View solution in original post

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Adventurer
Adventurer
383 Views
Registered: ‎05-18-2018

Re: How do I tell Vivado to treat signals as differential, and can I set this up in the Block Diagram editor?

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Thanks. Somehow I missed this.

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