Boyette, Ken

8b10b Encoder/Decoder

Lack of "Code violation" signal in the decoder.
It would be very useful.

Code violation signal

The pdf file "8b10b_encdec_v1d0" released with the src code is wrong about the squence of 5 LSB and 3 MSB during encoding process.

The pdf says so: "The MS 3 character bits are encoded by an internal 3b/4b encoder and the disparity, or difference in 1's and 0's is determined. The 5 LS bits are encoded by an internal 4b/5b encoder depending upon the disparity value from the previous 3b/4b coding."

Actually, the 5 LS bits are encoded fisrt, and the 3 MS bits are encoded according to the RD of the 5b/6b encoding result. I figured this with the simulation of my project using the 8b10b codec.

See the 8b/10b encoding page on wikipedia for more, it helps me make sure.

5 LS bits are encoded fisrt

In my application the data is validated from one enable signal and non at each clock signal. I tryed to  modify the encoder code but the K code is non correct while the other codes works well.
can you  help me?
thanks alot

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8b10b Encoder/Decoder