AN 846: Intel® Stratix® 10 Forward Error Correction

ID 683805
Date 7/02/2018
Document Table of Contents Transcode Encoder

The KR forward error correction (KR FEC) transcode encoder block performs the 64B/66B to 65-bit transcoder function by generating the transcode bit.

The transcode bit is generated from a combination of 66 bits after the 64B/66B encoder which consists of a 2-bit synchronization header (S0 and S1) and a 64-bit payload (D0, D1,…, D63). To ensure a DC-balanced pattern, the transcode word is generated by performing an XOR function on the second synchronization bit S1 and payload bit D8. The transcode bit becomes the LSB of the 65-bit pattern output of the transcode encoder.

Figure 7. 66-Bit to 65-Bit Transcoding