FEC-Only Decoder Interface Signaling for 50G Operation - 1.1 English

Versal ACAP Integrated 600G Interlaken with FEC Subsystem Product Guide (PG371)
Document ID
PG371
Release Date
2022-07-21
Version
1.1 English

In 50G mode, the bit ordering for the input of Slice0 of FEC0 decoder is as follows:

  • At the start of the codeword where rx_fec0_slice0_din_start=1,
    • rx_serdes_data0[79:0]=CW[79:0]
    • rx_serdes_data1[79:0]=CW[159:80]
  • At the second codeword cycle,
    • rx_serdes_data0[79:0]=CW[239:160]
    • rx_serdes_data1[79:0]=CW[319:240]
  • At the third codeword cycle,
    • rx_serdes_data0[79:0]=CW[399:320]
    • rx_serdes_data1[79:0]=CW[479:400]
  • At the 34th codeword cycle,
    • rx_serdes_data0[79:0]=CW[5359:5280]
    • rx_serdes_data1[79:0]=CW[5439:5360]
In 50G mode, the bit ordering for the output of Slice0 of FEC0 decoder is as follows:
  • At the start of the codeword where rx_fec0_slice0_dout_start=1, rx_fec0_slice0_dout[159:0]=CW[159:0]
  • At the second codeword cycle, rx_fec0_slice0_dout[159:0]=CW[319:160]
  • At the third codeword cycle, rx_fec0_slice0_dout[159:0]=CW[479:320]
  • At the 34th codeword cycle, rx_fec0_slice0_dout[159:0]=CW[5439:5280]

The bit ordering for all 50G decoder interfaces is similar to Slice0 of FEC0. See the following table for a summary of 50G decoder bit ordering.

Table 1. 50G Decoder FEC-Only Bit Ordering Summary
FEC Inst Slice Number Decoder Input Input CW Start Position Decoder Output Output CW Start Position
FEC0 Slice0 rx_serdes_data0[79:0]

rx_serdes_data1[79:0]

 rx_serdes_data0[0] rx_fec0_slice0_dout[159:0] rx_fec0_slice0_dout[0]
Slice1 rx_serdes_data2[79:0]

rx_serdes_data3[79:0]

 rx_serdes_data2[0] rx_fec0_slice1_dout[159:0] rx_fec0_slice1_dout[0]
FEC1 Slice0 rx_serdes_data4[79:0]

rx_serdes_data5[79:0]

 rx_serdes_data4[0] rx_fec1_slice0_dout[159:0] rx_fec1_slice0_dout[0]
Slice1 rx_serdes_data6[79:0]

rx_serdes_data7[79:0]

 rx_serdes_data6[0] rx_fec1_slice1_dout[159:0] rx_fec1_slice1_dout[0]
FEC2 Slice0 rx_serdes_data8[79:0]

rx_serdes_data9[79:0]

 rx_serdes_data8[0] rx_fec2_slice0_dout[159:0] rx_fec2_slice0_dout[0]
Slice1 rx_serdes_data10[79:0]

rx_serdes_data11[79:0]

 rx_serdes_data10[0] rx_fec2_slice1_dout[159:0] rx_fec2_slice1_dout[0]
FEC3 Slice0 rx_serdes_data12[79:0]

rx_serdes_data13[79:0]

 rx_serdes_data12[0] rx_fec3_slice0_dout[159:0] rx_fec3_slice0_dout[0]
Slice1 rx_serdes_data14[79:0]

rx_serdes_data15[79:0]

 rx_serdes_data14[0] rx_fec3_slice1_dout[159:0] rx_fec3_slice1_dout[0]
FEC4 Slice0 rx_serdes_data16[79:0]

rx_serdes_data17[79:0]

 rx_serdes_data16[0] rx_fec4_slice0_dout[159:0] rx_fec4_slice0_dout[0]
Slice1 rx_serdes_data18[79:0]

rx_serdes_data19[79:0]

 rx_serdes_data18[0] rx_fec4_slice1_dout[159:0] rx_fec4_slice1_dout[0]
FEC5 Slice0 rx_serdes_data20[79:0]

rx_serdes_data21[79:0]

 rx_serdes_data20[0] rx_fec5_slice0_dout[159:0] rx_fec5_slice0_dout[0]
Slice1 rx_serdes_data22[79:0]

rx_serdes_data23[79:0]

 rx_serdes_data22[0] rx_fec5_slice1_dout[159:0] rx_fec5_slice1_dout[0]