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Observer
Posts: 19
Registered: ‎11-23-2017

IODELAY application

Hi,

 

May anyone please explain what an IDELAY/ODELAY is? Where this primitive is used?

And where can I find simple examples of this primitive to learn its usage?

 

Thanks

Moderator
Posts: 875
Registered: ‎09-15-2016

Re: IODELAY application

Hi @mo69_hoseini

 

If you are using 7 series, refer this link below:

https://www.xilinx.com/support/documentation/user_guides/ug471_7Series_SelectIO.pdf

 

If you are using Ultrascale, refer the link:

https://www.xilinx.com/support/documentation/user_guides/ug571-ultrascale-selectio.pdf

 

I think you will get sufficient information in these doc.

 

Regards

Rohit

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Regards
Rohit
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Observer
Posts: 19
Registered: ‎11-23-2017

Re: IODELAY application

Hi @thakurr

 

In my book, the user guides are not suitable for beginners and it seems they are written for skilled designers who need to know how to use new technologies

 

I need something simpler. I know IODELAY is used for delaying inputs or outputs, but I don't know where they are necessary. Could you please give some practical and simple examples?

 

Regards

Scholar
Posts: 408
Registered: ‎06-09-2011

Re: IODELAY application

@mo69_hoseini,

One of the very useful applications is in fine-tuning of high-speed data bus - suppose it is coming from a high-speed ADC - when lines are not tunned in PCB!. you may know that in such cases, bits of the data bus may pass different traces to get to the FPGA, thus causing them to be unaligned to the input clock. So, to make everything fine tunned inside FPGA we use such elements located in IOB to overcome such problems. The similar situation may exist for output bus.

 

Hope this will help,

Hossein