cancel
Showing results for 
Search instead for 
Did you mean: 
Highlighted
Explorer
Explorer
335 Views
Registered: ‎04-19-2018

AXI interface to GTH

 

I've been using the Wizard-generated GTH transceiver for demonstration and eye diagram measurements.

Now it's time to do something useful. I need to input/output data from it, I assume AXI-Stream is the logical choice.

Is there any guidance on how to do that?

0 Kudos
7 Replies
Highlighted
Xilinx Employee
Xilinx Employee
289 Views
Registered: ‎03-30-2016

Re: AXI interface to GTH

Hello

GTH transceiver is not using AXI stream for data interface.
( Please see also UG576 Chapter3 and Chapter4 "TX/RX interface" section)

The data interface will be different, depending on your GTH configuration.
( For example 8B10B encoding vs RAW data )
You would probably want to generate GTH with your configuration , and run Example Design simulation to observe the behavior.

For GTH Example Design , please see also PG182 Chapter5/6 for a start point.


Regards
Leo

0 Kudos
Highlighted
Explorer
Explorer
255 Views
Registered: ‎04-19-2018

Re: AXI interface to GTH

 

I know. That's what I want to achieve. To add an AXI-Stream interface to it. Otherwise is not much useful.

0 Kudos
Highlighted
Xilinx Employee
Xilinx Employee
237 Views
Registered: ‎10-19-2011

Re: AXI interface to GTH

Hi @satguy ,

how about using an IP like Aurora?

------------------------------------------------------------------------------
Don't forget to reply, give kudo and accept as solution
------------------------------------------------------------------------------
Highlighted
230 Views
Registered: ‎07-23-2019

Re: AXI interface to GTH

 

@eschidl 

that's a good suggestion, unfortunately, I've been asked the 8b10b encoding to be optional. If there were a way for Aurora to send raw data (that I would encode and ensure there is no DC bias) then I would certainly ditch the GTH wizardry without tears besides those of joy. 

0 Kudos
Highlighted
Xilinx Employee
Xilinx Employee
217 Views
Registered: ‎10-19-2011

Re: AXI interface to GTH

Hi @archangel-lightworks ,

okay, that reduces your options quite a bit. I guess 64b66b encoding is optional too :).

With raw data I do not know of an IP myself that would provide AXI access. Maybe you could reuse parts of Aurora there. AXI is just the outer layer there.

------------------------------------------------------------------------------
Don't forget to reply, give kudo and accept as solution
------------------------------------------------------------------------------
0 Kudos
213 Views
Registered: ‎07-23-2019

Re: AXI interface to GTH

 

I started on the AXI interface from the example. It is not a big deal, actually. It's just how long debugging it until reliable enough can be.

Highlighted
Explorer
Explorer
140 Views
Registered: ‎08-14-2013

Re: AXI interface to GTH

The GTH transceiver is just a serializer. It accepts new data on every clock cycle. So you could consider it as an AXI stream endpoint that always has tready = 1 and expects tvalid continuously high. In general, you'll want to have some sort of a 'shim' in between the transceiver and your AXI stream interface that can properly encode/scramble the data as well as include framing information. You could use an Ethernet PHY for this, or Aurora, or roll your own that does something similar. Presumably you would need the same thing on the other end as well to pull the data back out and get it back into an AXI stream interface.