cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 
Highlighted
361 Views
Registered: ‎06-07-2019

Aurora 8b/10b Errors


Hi,


We are trying to develop a customized aurora 8b/10b with working at 12Gbps, which can replace the its equivalent of 64b/66b have found with 'not in table' and 'disparity error' sometimes.


Part Number XCVU440
Mode : DFE
TX Diff ctrl : 730mv
PLL : QPPL1
Cable lengths : 3/5m
Transreciever : generated with 2018.1


The originnal aurora  8b/10b ip is modified to send the recovery sequences intermittently in order to support the hot plug features. Apparently, the robustness of 8b/10b towards error concealing capability has found to be much lower compared to that of 64b/66b, eventhough we use a data scrambling at Lane symbol encoder level!
Is there any intrinsic reason for the poor performance of 8b/10 decoding with DFE ?

Regards,
Maddy



0 Kudos
2 Replies
Highlighted
Explorer
Explorer
320 Views
Registered: ‎03-16-2019

in ethernet 10g application, the protocol uses 64/66b encoding with scrambler but in 1 g ethernet protocol only uses 8b/10b.

from my point of view, 8b/10b and scrambling have an effect on prohibiting the reciever clock from unlocking. 

in an ethernet application, we can see the encoding is related to the data rate. 10/8 =1.25 ethernet 1G rate.

I think scrambling and 8b/10b have the same issue for the receiver's clock. 

64b/66 encoding is only for data alignment and in 10G ethernet show, start and end of the frame by its data code part.

as a result, the main part of the benefit of using 64b/66 is for scrambling after that, this thing you have in your protocol after 8b/10b.

 

Highlighted
Xilinx Employee
Xilinx Employee
238 Views
Registered: ‎06-01-2017

Have you tried LPM mode to see if the BER is lower? Can you add an in-system IBERT to plot eye scan to evaluate link margin?
-------------------------------------------------------------------------
Don’t forget to reply, kudo, and accept as solution.
-------------------------------------------------------------------------