Why are there periodic glitches on the transceiver Tx pins when using F-tile PMA/FEC Direct PHY IP in GPON mode with single-width transfer?

Due to a problem in the Quartus® Prime Pro Edition Software version 23.3 and earlier, when you instantiate PMA/FEC Direct PHY IP in GPON mode with signal-width transfer, you may see periodic glitches on the transceiver Tx pins.

To work around this problem in hardware, perform the following steps:

1. Navigate to <your ip directory>/.
2. Locate dphy_f_tx_dsk_gen.sv and change the following lines:

   From

      genvar l;
      for(l=0;l<LANES;l=l+1)  begin:lane
         assign o_data[l*80+:80] = DOUBLE_WIDTH_ON ? {i_data[l*80+79], tx_dsk_pulse, i_data[l*80+:78]} 
                                                   : {i_data[l*80+79 : l*80+37], tx_dsk_pulse, i_data[l*80+:36]};
      end : lane

   To

      genvar l;
      for(l=0;l<LANES;l=l+1)  begin:lane
         assign o_data[l*80+:80] = DOUBLE_WIDTH_ON ? {i_data[l*80+79], tx_dsk_pulse, i_data[l*80+:78]} 
                                                   : {i_data[l*80+79 : l*80+37], 1'b0, i_data[l*80+:36]};
      end : lane

This problem has been fixed starting from the Quartus® Prime Pro Edition Software 24.1.