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Visitor markus_iis
Visitor
337 Views
Registered: ‎11-26-2015

UltraScale+ GTH Latency

Hello,

 

I need for my application a deterministic latency in the GTH-Transceiver RX-Path.

I do not use comma-alignment but I have to use the elastic buffer. I cannot deactivate the elastic buffer inside the GTwizard (1.7)  because if I do it I cannot use the Physical Resources I need  (QuadX0Y1 and QuadX1Y1 together).

I read here: https://forums.xilinx.com/t5/Networking-and-Connectivity/Artix7-GTP-Latency-AR-58981/td-p/776644 and here: https://forums.xilinx.com/t5/Serial-Transceivers/GTP-transceiver-Deterministic-latency-through-RX-datapath/td-p/829135 that it is possible to read the latency of the RX elastic buffer. But I could not find anything like this in the ug576.

Is it also possible to read the current latency of the rx elastic buffer from the GTH-transceiver of a Ultrascale+ device?

 

Thank you,

Markus

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2 Replies
Moderator
Moderator
294 Views
Registered: ‎07-30-2007

Re: UltraScale+ GTH Latency

You can't read current information on the data pointers and be assured of the latency.  What is your line rate?  You should be able to do buffer bypass across 2 quads.

Roy


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Visitor markus_iis
Visitor
270 Views
Registered: ‎11-26-2015

Re: UltraScale+ GTH Latency

Hello Roy,

 

thanky you for your fast answer.

My linerate is up to in between 4 and 12 Gbit.

If I disable the elastic buffer:

elastic_buffer_disabled.PNGdisable elastic buffer

 

I am no more able to choose Channels from the other column (from the same column it´s possible):

second_quad.PNGchoose additional channels

Best regards,

Markus

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