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Contributor
Contributor
880 Views
Registered: ‎02-16-2018

Aurora 64b/66b link not stable

Hi,

I am using Vivado 2017.4 and KC705 (kc7k325tffg900-2) Evaluation Board.

I have used aurora TX-only simplex and RX-only simplex, both IP's are configured to 1 lane each, 10Gbps line rate and 156.25MHz gt_ref_clk.

I am referring following document to generate 156.25MHz gt_ref_clk for aurora.

https://www.xilinx.com/support/documentation/boards_and_kits/kc705/2014_3/xtp202-kc705-si5324-c-2014-3.pdf 

I have programmed Aurora-TX on one board and Aurora-RX on other board, both are connected through optical cable. Initially after power on I am seeing tx_channel_up, tx_lane_up, rx_channel_up and rx_lane_up, But after asserting pma_init for Aurora-TX the link is lost I am not seeing rx_channel_up and rx_lane_up back until and unless I reprogram the board. but Aurora-TX side both tx_channel_up and tx_lane_up are there.

I tried asserting reset_pb on Aurora-Tx the link is stable.

The link stable when Aurora-RX reset_pb and pma_int are asserted.

somebody help me on this.

Thanks

Iranna

4 Replies
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Xilinx Employee
Xilinx Employee
843 Views
Registered: ‎03-30-2016

Hello Iranna i@007

Aurora 64B66B has Auto link recovery features, as mentioned in PG074 Chapter2.
XF_AURORA_64B66B_Auto_Link_Recovery.png

So, if you reset TX simplex, TX will stop sending K28.5 , so RX simplex will be initialized automatically.
BTW, Please see also PG074 chapter3 for a correct reset sequence procedure.
Asserting TX simplex pma_reset only (as mentioned in your post) does not match with chapter3 reset guidance.

 XF_AURORA_64B66B_Chapter3_Reset.png
Thanks & regards
Leo

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Contributor
Contributor
818 Views
Registered: ‎02-16-2018

Hi Leo,

Thanks for replying.

In design I have a global reset from which I am generating reset_pb and pma_init for aurora as per user guide, Still I loose link on Aurora-RX that's why for debugging I have connected reset_pb and pma_init externally just to know which is causing link loss.

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Xilinx Employee
Xilinx Employee
810 Views
Registered: ‎03-30-2016

Hello Iranna i@007
I just realized that you are using 2017.4. Could you please try IP from Vivado 2018.2 ?
Aurora 64B66B IP has a bug fix related to Auto-link feature.

XF_IRANNA_AURORA_SIMPLEX.png


Thanks & regards
Leo

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Contributor
Contributor
768 Views
Registered: ‎02-16-2018

Hi Leo,

I tried with Vivado 2018.2 but still I am seeing the same issue.  

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