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fxu001
Novice
330 Views

How to interpret 8b/10b convert in the JESD204b bus

Hello,

 

  1. Observation: From one of 16 bits output signal outxTxSerialData in the JESD204B serial bus, I can figure out that there are 40 bits transitions during one clock (tx_link_clk_clk) cycle, that scenario meant that the input has 32 bit parallel data when JESD204B used 8B/10B encoding technical from your JESD204B datasheet . From your protocol there are up and low 32 bits parallel data transfer to form 64 bits parallel data that matches your AV bus input. As a result, 64 parallel bus coordinate with one bit serial bus in the JESD204B output
  2. Confuse: When I pick up one output serial bus, the 10 toggling patterns are 1111101011 following with 0000010100 during half of tx_link_clk_clk clock cycle, which it preforms RD=-1 and RD=+1 patterns generation. Now I review the 8b/10B encoding table, and none of above pattern matches the Wikipedia .
  3. Requirement: Can you give me the encoding technical table so I can detect whether input parallel data through JESD204B IP is correct or not? It will be benefit during my system bring up
  4.  

Thank you so much for your help in advance!

 

-Fred

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6 Replies
Nathan_R_Intel
Employee
53 Views

Hie Fred,

 

My sincere apologies or the delayed first response. I mixed up this question with another and hence missed responding to this thread.

Please check my response on the 8B10B encoding.

 

An example for K28.5 encoding technical table is shown in the attached diagram.

 

The information is also available in our user guide below (Pg2):

https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/ds/dsed8b10b.pdf

 

However, to read the parallel data, please disable scrambling; otherwise you will be reading incorrect values. I am suspecting scrambling is enabled; hence you cannot read the correct data.

 

 

Regards,

Nathan

 

fxu001
Novice
53 Views

Hi Nathan, Great info! I see. I will disable the scrambling during debug. Thank you so much:) Thanks, -Fred
fxu001
Novice
53 Views

Hi Nathan, which module do disable scrambling in TX and RX? Thanks, -Fred
Nathan_R_Intel
Employee
53 Views

Sure,

 

Is your issue resolved?

 

Regards,

Nathan

fxu001
Novice
53 Views

Hi Nathan, I am working with another project. I might get back to you after two weeks. Thank you so much😊 -Fred
Nathan_R_Intel
Employee
53 Views

Sure. Do let me know if you have further questions.

 

Regards,

Nathan

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