General Description: Version 1.0 of the 8b/10b Decoder core will give incorrect disparity checks and "code_err" flags for some of the symbols.
The incorrect flags occur on certain combinations of the lower six bits of the input symbol. These the incorrect symbol errors can be seen in the behavioral models in the b6 (the lower 6-bit block) process.
WHEN "000110" => b6_disp <= neg ; --D.0 b6_err <= FALSE; -- RF: Found a bug here: true;
WHEN "100111" => b6_disp <= pos ; --D.8 b6_err <= FALSE; -- RF: BUG found here: true;
WHEN "110011" => b6_disp <= neg; -- RF: found bug here pos ; --D.24 b6_err <= false ;
Solution
This issue has been fixed in Version 2_0 of 8b/10b Decoder, which is available in IP_Update#3 (D_IP3) and newer IP updates.