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Visitor
Visitor
8,751 Views
Registered: ‎07-01-2016

Tuning of GTX Receiver for Custom Protocol

Hello,

 

We are trying to implement a custom protocol on Zynq ZC706 platform, but we are seeing issue in the GTX RX path. Since this is a custom protocol, there are no straight forward values for CDR and other tuning related attributes. Most of such values are listed as "use Wizard generated values", which may not work for a custom protocol. We are starting with 5 Gbps data rate and targeting to achieve 10 Gbps data rate. I understand that tuning may be different for different data rates, but that can be addressed later once we get hold of it. In initial tests, we are seeing 1-bit error occurring in the RX data path when we try to run it at 5 Gbps. 

 

Can someone point me to a document or link that outlines method to tune the GTX receiver for custom protocol? Any recommendations for better RX results will be highly appreciated.

 

Thanks!

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Xilinx Employee
Xilinx Employee
8,741 Views
Registered: ‎08-01-2008



you can use custom options .

http://www.xilinx.com/support/documentation/ip_documentation/gtwizard/v3_3/pg168-gtwizard.pdf
Thanks and Regards
Balkrishan
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Visitor
Visitor
8,738 Views
Registered: ‎07-01-2016

Hi Balkrishan,

 

I have checked the wizard and 7-series GTX documentation and none provide specific help on addressing the receiver tuning. e.g., I am getting 1-bit error in RX path couple of times (by looking at the received data) with the settings generated by GT wizard. What can be done to detect the source of error and resolve it?

 

Thanks.

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Xilinx Employee
Xilinx Employee
8,736 Views
Registered: ‎08-01-2008

can you please copy error message
Thanks and Regards
Balkrishan
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Visitor
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Registered: ‎07-01-2016

It's not the error message that we are getting. This error was observed by using chipscope and probing the received parallel data.
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Moderator
Moderator
8,702 Views
Registered: ‎02-16-2010

What is the error rate?

Can you mention the similarities of your custom protcol with any of the standard protocols?

Please make the 5Gbps link work error free to start with.

If the attenuation of the link is more than 12dB, select DFE otherwise try with LPM.
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Visitor
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Registered: ‎07-01-2016

Hi @venkata,

 

Are you asking about required error rate or achieved error rate? The required error rate is 1e-12. I am not sure how to measure the achieved error rate. It would be good if you can point me to how to measure it. I found that the RX configuration also depends upon the board and other factors, so some parameters may need to be tuned, I suppose.

 

My custom protocol is similar to PCIe. I have an add-on board that goes on FMC interface of the ZC706 Kit. I am not sure what is the impact of this add-on board on the overall channel. It would help me a lot if you can provide some step-by-step pointers for debug as we are using GTX for the first time.

 

Thanks.

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Visitor
Visitor
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Registered: ‎07-01-2016

Hi,

 

Can anyone point to a troubleshooting guide for 7-series GTX? How to debug and detect issues in GTX configuration for a custom protocol?

 

Thanks.

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Visitor
Visitor
8,344 Views
Registered: ‎07-01-2016

Can any one help with this query? If not, can someone point me to appropriate Xilinx Support channel, if available?

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Moderator
Moderator
8,327 Views
Registered: ‎02-16-2010

Have you checked the HSSIO solution center?
http://www.xilinx.com/support/answers/57237.html
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