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64B/66B encoding and decoding support for custom data

Ron2197
Novice
375 Views

Hello,

I want to use 64B/66B encoding and decoding for custom data without the use of 10GBASE-R protocol.

I tried to configure the transceiver wizard but it gave errors saying that 64B/66B encoding and decoding enable is invalid.

I have gone through Arria 10 and Stratix 10 Transceiver User Guides and have observed that both the user guides mention 10GBASE-R protocols for enabling 64B/66B encoding and decoding.

 I would like to know which FPGA part will support 64B/66B encoding and decoding with "Transceiver Configuration Rules : Basic (Enhanced PCS)" for line rate above 12Gbps.

Thanks and Regards,

Ron

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6 Replies
CheePin_C_Intel
Employee
345 Views

Hi Ron,


As I understand it, you would like to use the 64B/66B encoding/decoding blocks without using the 10GBASE-R mode in Native PHY. For your information, these blocks are only available using 10GBASE-R mode. I am not aware of specific device which support 64B/66B encoding/decoding blocks without 10GBASE-R mode. As a workaround, you might want to look into coding your own soft 64B/66B blocks for your use case. Sorry for the inconvenience.


Ron2197
Novice
342 Views

Hello CheePin,

Thanks for the confirmation. Are there any Intel FPGA IP cores  which can be used for 64B/66B encoding outside the transceiver?

I would like to know whether I can use 10GBASE-R for any desired line rate or is it fixed to 10G only(Single channel without channel bonding). Note: The reason for asking this question is cause I have observed in the Intel® Arria® 10 Transceiver PHY User Guide that the architecture for 10GBASE-R shows fixed values of clocks and line rate with the line rate shown to be 10.3125 Gbps. 

The required line rates for my application may come in the range of 12Gbps to 24Gbps on single channel. Will it be possible for me to implement this using 10GBASE-R without channel bonding?

Thanks and Regards,

Ron

CheePin_C_Intel
Employee
321 Views

Hi Ron,


Thanks ofr your update. Regarding your latest inquiries, as I understand it, there is no specific IP for 64B/66B encoding available. 


Regarding the 10GBase-R Native PHY, your understanding is correct, all the line rate is fixed to 10.3125Gbps to comply with the specs. Therefore, you would not be able to change the data rate to other values. Sorry for the inconvenience.


You might want to look into using your own soft 64/66B encoder as workaround.


Ron2197
Novice
318 Views

Hello CheePin,

Thank you for the help.

Till now, what I have understood is that 64B/66B is supported only 10GBASE-R and supports line rate of only 10.3125Gbps. The 64B/66B encoding should be done by User Logic in case any other protocol is needed to be implemented.

Here are few queries I have regarding the configuration.

 Ill use Intel Transceiver with following configurations 

  • Transceiver Configuration Rules : Basic (Enhanced PCS)
  • Transceiver Mode: TX/RX Duplex
  • Number of Channels: 1
  • Data Rate: in the range of 12Gbps to 24Gbps

     Enhanced PCS settings

  • Enhanced PCS/PMA interface width: 64
  • FPGA fabric/ Enhanced PCS interface width: 66
  • Tx 64B/66B encoder: Disbaled
  • Rx 64B/66B decoder: Disbaled

Note: I have mentioned the settings which looked necessary.

Let us assume the scenario, where I will be using the above configured transceiver and I will loopback the data.

Query 1: If I provide the 64bit data and 2 bit header, whether the transceiver will append the header to the data and create the 66bit serial data which will be transmitted on the differential line or will it do this only when 64B/66B encoding is enabled? ( I am under the impression that the header is only appended to the data when 64B/66B encoder is enabled, hence would like some clarification regarding this)

Query 2: If the above query holds good (Header will be appended to data even though the 64B/66B encoder is disabled) then whether the Transceiver Rx logic will decode the data properly ( provide the 2 bit header in the header bus and 64bit data in the data bus) and give it to the user?  (Note: Raising this query with the assumption that if the Transceiver Tx can append header even when 64B/66B Encoder is disabled then the Transceiver Rx will be capable of removing the header from the serial data even though the 64B/66B Decoder is disabled)

Query 3: Whether the received data will be properly aligned always or is there a possibility for the decoded data to be misaligned? 

For now these are the basic doubts I have regarding the Transceiver Functionality and would be glad if these could be cleared.

Thanks and Regards,

Ron

 

CheePin_C_Intel
Employee
295 Views

Hi,


Thanks for your update. 


Regarding your latest inquiries on the behavior of the XVCR with 64/66 bit interfaces, sorry as I do not have much insight into how the behavior would look like. As a workaround, I would like to recommend you to create a simple one channel test design and perform a Modelsim simulation to check on the functional behavior. The simulation would replicate the expected behavior of the XCVR and can help to clarify your queries.


Please let me know if there is any concern. Thank you.


CheePin_C_Intel
Employee
266 Views

Hi,


As I understand it, it has been some time since I last heard from you. This thread will be transitioned to community support. If you have a new question, feel free to open a new thread to get the support from Intel experts. Otherwise, the community users will continue to help you on this thread. Thank you.



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